'06 Dodge ram 5.9L warm idle/short cycling

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'06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Tue Jun 21, 2016 2:36 pm

Hi everybody,

I have a multi-part question but i'll give some background first. The truck has 160k miles and started to blow warm during idle with the A/C on. I decided to replace the accumulator, liquid line (which contains the orfice tube that cannot be removed) and recharge the system. After pulling vacuum and charging the system with the proper amount of R134a (weighed) the system is still short cycling. I will provide more of my own analysis in the appropriate question to keep from confusing people and more importantly myself!

1) I believe my fan clutch to be bad. It is electronically controlled and I never hear it Kick on to 100%. With the truck idling and manifold gauges connected, it runs fine until the condenser heat soaks. After just a few minutes of normal idle operation, both low and high pressure sides get high, 100/450 (90* ambient), at which point the compressor shuts off until the pressures drop. It then comes back on for a few seconds until pressures rise, and then shuts off again.
My question is, if a pressure switch is telling the system to shut off, would this be the same switch that tells the fan to turn on? Or is there an another sensor that tells the PCM to turn the fan on. I don't want to replace a $400 fan clutch if it is not at fault.

2) After more reading, I now know that I did not run the vacuum pump long enough. It was very humid here, and I only ran the vac for about 45 minutes. I only got down to about 20 in/hg which is not enough. The vacuum pump also had steam coming from the exhaust. After charging my truck I charged the wifes scion and it pulled 29 in/hg right away with no steam from the vac. Her car now blows 36 degrees from center vent at idle with 90* ambient.
Since I saw steam while pulling my truck down, but not her car, I can assume that was moisture from my system working its way out because of the new components and humid Oklahoma weather. Is watching for steam along with the gauge a good indicator of needing to vac more until steam is no longer present?
After closing the center valve and turning the pump off, I lost vacuum fairly quick, which I read is indication of moisture boiling off during the vac process. The system however does hold pressure and shows no sign of a leak after checking with UV light, soapy water, and a Mac sniffer. Is it true that the system may not hold pressure if there is substantial moisture present?

I am planning on round two this weekend. I want to let the vacuum pump run for the better part of a day and hopefully get it down to 28-30 in/hg. Does this sound like my logic is reasonable or am I looking at a bigger problem here?

Thanks for your time!
Kevin
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby cornbinder89 » Tue Jun 21, 2016 4:36 pm

Raising vacuum can be moisture boiling off but also could be a leak. If the system is "wet" it can be hard to get all the moisture out in one go. Ideally you would sweep charge with dry nitrogen two or three times before final vacuum and charge with 134a.
If you can't hold a vacuum, find out why before proceeding.
Sounds like the high pressure safety is shutting down the compressor before a hose blows or the relief valve opens.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Tom Greenleaf » Tue Jun 21, 2016 4:48 pm

Hi Kevin - Welcome. Not much time right now, hope colleagues chime in quickly too.

Sorry if already include why you chose to replace those two items. Begs questions first.

So it wasn't blowing cool for you and you replace accumulator, liquid line and an "O" tube was already in new line as you seem to know.

Need to know if you cut old "O" tube out what it looks like or what oil looks like as well. Did you have reason to believe the items replaced were leaking? How much refrigerant if you know came out if you know? It may not have been low as a reason or leaking so far unless I missed it.

So, when low and unfortunately if run and can't keep up because of a failure - not blowing properly cool but about to the oil in system is not lubing the compressor enough so it's highly likely a fault you'll probably see debris in oil or a clogged "O" tube. Condensers are all some sort of high efficiency with strange flow patterns so catch debris and really can't be flushed out for the next likely steps. It's a toss every time thing unfortunately if debris isn't removed or the cause which is about always the compressor. If when starved for return proper refrigerant it isn't carrying oil and would burn out quickly. Stinks systems don't just shut down earlier IMO,

Your one high reading is enough to shut it down. I just can't know each model of everything but that's way too high. Whatever fan set up you said a clutch may not even be getting warm air to pull harder with a blocked condenser inside. You could do without a fan at all just using water over one as a test much more heat transferred than air and pressure should plummet.

Good for you for being able to put back exact known charge. Pressure so high it would cut out system. How you re-enable this exact one I'm not sure but that's just way to high for anywhere around 95F ambient temps. Figure if OK 2.5 X the temp in F. of air coming in thru grille.

IDK - Condenser must be clean enough. Some can hide junk in between condenser and radiators so if everything was fine air can't ge thru well enough, temps not telling good info to anything and a non electronic fan may not know. HPCO is the high pressure cut out switch acronym meant to shut down by those pressures.

So - for now I think you should verify debris in the "O" tube, compressor does pump but doesn't mean it's not making a muddy debris field down stream.

Check more first as you are probably back to before you started which is a bummer with A/C.

Early guess is a leak was a cause, low oil circulation and compressor damage and the Domino effect down stream clogging condenser and "O" tube. Do some looking around so next round it's done once and forget it for a good time with I think a new compressor, accumulator, condenser, "o" tube if replaceable now unknown, and the whole system flushed out.

While pressure is in it now you should rule out any other leaks. Evidence of oil at connections and drain tube for evaporator can't be making water but oil could be there a horrible sign that evaporator is leaking! Once the most common cause with some "Mopar" vehicles. None any fun to do.

Again, do as much checking now with pressure in there. Plan on a lot more and even losing what you 've already done - stinks but think real likely,

T
PS: Know how the fan clutch is really supposed to work. If still (I just don't know) an HD temp sensing clutch not any tricks to it with just engine heat air flow should be pulling hard when hot, just shut down for a few minutes and run again there should be a rush of hot engine coolant and it should respond fairly quickly - just hear or feel airflow, temp of it and clutch relax when it cools down some and should even at just 95F.....
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Tue Jun 21, 2016 5:39 pm

Hi Tom,

First, I replaced the accumulator and o tube because a friend of mine said they are "regular maintenance items." Being new to AC and with very little research I decided they were cheap and easy enough to replace if I was going to evacuate the system anyway. I just cut the old O tube out of the line and it is clean which sounds like a good thing to me.

I forgot to mention that I did run the garden hose over the condenser while the system was short cycling and the pressures dropped and compressor ran continuously. This is why I think its a heat soak/fan problem. My biggest concern is that I don't want to replace a $400 fan clutch If I only need to replace a $30 pressure switch/sensor. Most guys with the common rail cummins report a DTC code with faulty fan clutch, but im not getting one.

The other issue is, my coolant never gets hot at idle, or anytime for that matter. I suppose the condenser might need more air flow than the radiator to function properly, But why would the fan suffice for coolant, but not AC.

I do not know how much 134 came out of the system unfortunately. It has been holding a static 120psi of refrigerant (checked when engine is cold & not running) since Friday, So I don't suspect a leak anymore.

I do need to clean out my radiator fins. I saw the post about cleaning the radiator, not just the condenser when the AC blows warm during idle. With a quick visual inspection I did see seeds and some debris, so I will have to take care of that

I will also look into dry nitrogen before running the vacuum next time. I plan on Friday or Saturday so I have a few days to prepare.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Tom Greenleaf » Tue Jun 21, 2016 7:17 pm

I see you are on line so come back when you should get a notice of this reply made. I can't be here all the time and sorry there's already lots to read and comment on.

* You don't need to run a vacuum pump longer than it takes to reach a full vacuum for you altitude. That's 29.92 Hg and can deduct 1 Hg for each 1,000 ft. of elevation. You could run the vacuum if it's empty till the cows come home - freaking empty is empty what more are you taking away from nothing. Rather you let it hold for a time. All day is nice and it stay there but at a minimum 30min. or more.

* Cold water if condenser was only 1/3 working would make it work? It's path like a maze thru it. If blocked and now think it is just one port unseen you lose about (guess) 1/3rd. Antoher is another 1/3rd. Hard but could possibly see that there are hot spots with an IR thermo where it's working/flowing and quick just cold (ambient possible) temps where nothing is happening or fast enough. You saw 400 PSI at the port which is what the HPCO is seeing.

* Don't know what came out. You are anonymous so just say. How did you empty it? If you slowly let it leak out what was in there you lost nothing but refrigerant. A blow out you lost oil. If recovered to a machine and saved it only removes mostly just the refrigerant not oil which is all important to the compressor it it's game over for the thing. You saw some debris and need to inspect that more when you can. It really can only be particlues of a blown compressor as not much else moves. No fix, needs to be replaced any reason they wear out and throw debris. The debris is probably the current problem but if all is not fixed at the same time and clean, proper charge and oil added from totally flushed out you'll just keep blowing the compressor, take out a brand new condenser again and the "O" tube you can't see yet for yet another new line and accumulator or risk (some) debris in that or any drier as that wont flush out.

I guess it could be argued that you should service A/C with time and age but I don't buy that. If a system is working perfectly leave it alone. Fans and clutches to compressors may need work or replacement - one a measurement the fan how well they pull air which really isn't involved when moving along probably at 40+ MPH incoming air is enough - some will notice this and shut down energy wasting fans that are controlled by the PCM via a reference signal from the HPCO.

Find leaks as already said. Pay someone to find leaks if needed as the sum total of possible equipment would way outweigh the few thousand I think you are looking at to just quit and send this whole thing out. Yes, that shocking!

* What makes this fan clutch $400 bucks? Do you know? I could search out all possible parts on this thing and still not come up with all answers. Does this have BOTH a fan clutch and electric fan? IDK - trucks you can order will all kinds of HD items one by one, oil coolers, extra cooling for engine - trans a separate cooler and power steering too and more I forgot.

Those if there also block the air flow thru the whole set up adding to struggles of cooling everything enough so any dirt on fins just adds troubles.

* One more for now and I'll be back or another. How did you or are you charging this such that you had a clue how much "refrigerant" went in, to a well held vacuum - no air allowed even in lines of gauges!? How?

* I lied - one more. I asked earlier if any fan action is blowing well to feel it blow on thru. Does it or not? Trying to figure out this fan clutch that costs a bit much for even good thermostatic but not connected to any controls other than their own temp sensing.

---------------------------------------------------

Last - sorry about a snag in the site. Know that first posts are in limbo till approved by a moderator. You were and still needed a second approved to show which isn't normal for that "spam" control for this site. Sorry about that - no clue why it did that.

I'll be back as there are more spammer at work while I'm even typing to get rid of.

Check on some more and need any pertinent history also so we can target just what moves you should make. I know much of the US is insanely hot today and more to come. It's only a chllly 90F here right now W 2:15 PM EDT which isn't so bad as it's not that humid and a nice breeze,

Tom
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Tue Jun 21, 2016 8:35 pm

Tom,

When I said let the vacuum pump run longer, I was meaning to allow it to fully come down properly. At around 2000' MSL I will be looking for 28in/hg. It wouldn't come down below 20 in/hg, I'm assuming due to moisture.

The system was bled slowly to atmosphere, I called a local shop and he said he releases to atmosphere because r134 doesn't need to be recovered...not sure if this is true, but I wasn't going to pay someone to do the same I could do for free. No Oil was lost, I also drained the accumulator into a cup, marked a line, cleaned and added the same amount to the new accumulator.

It is very probable that air entered the system through the lines when I was charging it. I used straight 12oz cans of R134a, no sealers. I weighed a can empty and continued to weigh the last can until I was at the required 1lb 14oz for my truck. Next time I will properly bleed the lines before opening the shraeder valves

As for leaks, Im not convinced its leaking. I tested with UV light, soapy water, and had someone use a Mac sniffer. The AC blows cold while moving, I think the problem from the beginning has been with the pressure getting too high, and the compressor shutting off to prevent a blown line or destroying the compressor as cornbinder mentioned. Tracking down the cause of the high pressure is now my focus. I know the system is not over charged.

The fan clutch is expensive because it is an electronically controlled viscous clutch. I have also heard box store parts are not worth the time and money, so MOPAR it is. I have no Trans cooler because it is manual, but it does have a power steering, oil cooler, and intercooler between the condenser and radiator. I did not feel any change in air, or audible tone when turning the AC on while the truck was idling. Im going to take it to dodge and see if they can use their STAR scan tool to figure out why the fan isn't coming on.

The debris was external, in the cooling fins of my radiator, I will flush that out with a hose. The O tube was clean, no signs of a blown compressor.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby cornbinder89 » Tue Jun 21, 2016 8:48 pm

Having no experience with the make and model, my comments could be worthless, but it my experience that controls are more likely to be at fault than the clutch. When the head pressure rises, something need to tell the clutch to lock. That it what I'd look at.
It is very possible that the clutch is controlled by the ECM, and the "sensor" for high pressure is not a simple off/on device, so learn how the system works before poking around, ECM's don't like it when 12 volts is fed in a 5 volt sensor circuit!
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Tue Jun 21, 2016 10:53 pm

corn binder you are correct. The pcm uses ~5 different inputs to control the fan speed. Dodge however uses a TIPM which makes the situation more complex. only dealerships and specialized mopar mechanics have the STAR Scan tool required to diagnose most issues with the system. I made an appointment with a local guy for next Wednesday because that is his earliest appointment.

In the meantime, while trying to track the mechanic down, while driving I got a strong refrigerant smell and lost all cooling capabilities. Once I got to him, he suggested a relief valve may have popped on the back of the compressor. Once the truck cools a bit I will put the manifold gauges back on and see what the static pressure is. Not sure if I lost all the refrigerant or just enough to stop the compressor from cycling at all...
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Tom Greenleaf » Wed Jun 22, 2016 5:46 am

Just this for now, Quote">> At around 2000' MSL I will be looking for 28in/hg. It wouldn't come down below 20 in/hg, I'm assuming due to moisture.<<"

I take that as you are 2,000 ft. above sea level - right? 28Hg would be about right if so.

Moisture of area has nothing to do with it. Who told you that? Moisture CAN'T exist in a vacuum - period. Nothing is nothing.

The only reason we can measure vacuum at all is because we forget we live in atmospheric pressure which is about 14.7 PSI at seal level again. Less what at altitude up to unlivable for a human.

Think on this: Air we live in is NOT nothing at all. Mega ton air planes like a loaded up 747 passenger's and load can fly at just ~250MPH at seal level air density. It can't go that slow at altitude. You can't breath at the altitude they fly at so pressurize cabins - you've hear of that hopefully.

Water if pure under pressures of seal level boils at 212F. Add 1PSI pressure and it boils @ 215F and so on. Reduce PSI and the boiling point is reduced. This is where you see cooking directions for foods the instructions may include "high altitude" times for things.

There are pressure cookers that are allowing liquid water to be much hotter than 212F and stay a liquid. Hence it's faster.

Refrigerants are purposeful condensable gasses with no pressure and a liquid with pressure about exactly like the propane bottle for a BBQ grille.

A/C is just capitalizing on the forces of changing state from solid to liquid (solid not applicable here) or liquid to vapor/gaseous is either consuming power to change state absorbing heat from a liquid to vapor takes away 2X the power that it took to be a liquid under pressure.

Simplify that: Put or spray water on your arm for example. When it evaporates it feels cool as it's taking heat away to do so.

Science, science, science* - will make your head explode but it's all about just that and the exact character of the refrigerant types used to force it to do what is needed at the right locations,

T

* PS: Light of heart with no mal-intent - we were the students with broken glasses fixed with a Band-Aid actually listening to a teacher. Probably not the life of a party but someone has to understand this stuff....
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby cornbinder89 » Wed Jun 22, 2016 11:26 am

Water like refrigerant in liquid form will show no pressure on the gauges, as it boils to gas, it will expand and show pressure, so if a system is really wet, it is possible to see a rise in vacuum (psia) but a leak is more likely. There would have to be a lot of liquid water. Conditions outside the closed system have no effect. So high humidity is a red herring.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Wed Jun 22, 2016 6:29 pm

I feel like I am not explaining well enough. The high humidity was referring to when I changed the parts and the system was open. Would the water vapor in the air not enter the dry system? Once the system is then sealed, I would need to extract that vapor, preferably with dry nitrogen as I learned here, or less efficiently with a vacuum pump.

If moisture cannot exist in a vacuum, why do people run the vacuum pump longer than it takes to achieve the 28 in/hg, or the proper correction for their altitude? Is the pump running longer than it takes to get to that point a waste of time? I'm not challenging your response, just wondering for my own understanding.

You are correct 2000' Mean Sea Level is my elevation. My wifes car pulled down to 28 in/hg almost immediately and continues to blow sub 40* air from center vent. So I know the vacuum pump is working.

Cornbinder- If the water boils and becomes vapor/gas and expands, pressure would negate the vacuum right? This is my logic in thinking that I need to run the vac pump longer to fully eliminate the water from the system. Maybe i'm missing something, but i'm trying to grasp these concepts that I've never dealt with before.


I also used a sniffer again yesterday after the AC quit completely. Nothing was picked up through any of the vents. I had someone tell me that the sniffers are designed for r12, and don't work with 134a. I have a hard time believing that.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Tom Greenleaf » Wed Jun 22, 2016 7:59 pm

Basics: Your humidity for pulling a vacuum means nothing. End that thinking. A full vacuum of absence of vapor - any. Water vapor, all contents of ambient air. Some liquids like oils remain in a vacuum others don't.

H2O - Water - pure. Ice will not stay in a total vacuum - we can argue about it but as pressure is reduced unless it's hiding inside some desiccant or couldn't be reached would or should go directly from a solid to a vapor just as snow or ice in you freezer evaporates or can. It's unique to water and it's states - solid, liquid, vapor.

Good grief why did you touch the other car? Don't touch quiet working systems - no need.

Sniffers are sensive CFCs. They'll detect R-12, R-22, R134a, Propane, butane, natural gas, iso-butane found in like a Bic lighter even to test it.

The good ones cost a fortune and you set for PPM or mine does. That's like a leak of 1 gram in a tight garage of a CFC! A bit too much as fuel (gasoline) and other crap is just around so an item you get used to.

Hg = Inches of Mercury the liquid metal used in thermometer until it killed a rat. In a tube of glass sealed the weight of the liquid metal drops so many inches which is why it's referred to as inches of mercury. You could literally do that but gauges are certainly more handy digital or analog.

The area of a whole system to me is actually unknown if bone dry and just atmospheric air was in it. Accumulators at a glace some look like a quart or so other items smaller. In vapor form a half way decent vacuum pump would pull a full vacuum in perhaps 5-10 minutes sometimes more. You can buy faster ones just wait longer as zero is zero no matter how you get there you can't take more away from zero. Try it with a checking account they'll be happy to explain!

Back to seeing vapor from a vacuum pump: You may see something but it's not water vapor. Maybe some oil mist or something that would quit early or from the pump itself if not working properly or defective.

More: If it did have a spoon ful of water in a system just like on a stove you cook on would make a lot a vapor without pressure if it was hot enough.

The state of things common to us is totally a known calculation of what, at what temperature and under what pressure.

Wherever you stumbled across nitrogen or dry nitrogen just forget that. Nitrogen gas is used to legally look for leaks using a smidge of R-22 - a total waste of time IMO but on the books as legal.

--------------------------------------------------
Back to the truck only please: Unfortunately you didn't know for sure what the problem was when you first checked it out. You don't always get a chance with assorted problems with refrigerant involved at all if almost gone the static pressure below the ambient temp as listed on the chart is essentially empty. Equal or on spec with the chart just static you don't know how much was in the system meaning how much it weighs - what's left. That info you find pulling the gas out by machine that will compress it and weigh what came out - important when at all possible to know that and don't always get that chance if empty for example. If compressor has any pressure at all to engage it has some.

The key to this is from early on in this thread. Oil is only in with the refrigerant to lubricate a moving pump - the compressor. Oil doesn't move unless refrigerant carries it around in a loop -- compressor on thru any drier, on to condenser, on to + thru O tube or Expansion valve, on thru evaporator then back thru an accumulator for CCOT systems to return gas and some oil back to compressor and do this all over again and again.

Here's the snag. When refrigerant can't move oil and compressor can still operate it's not lubricated so burns out. It's a pump not designed to compress or pump without lube. Running dry totally could be as little as under a minute of time from new to total junk if bone dry.

So, this happens and makes debris that is clogging up condensers that don't tolerate that nor can be cleaned out. Any that got thru continues to wreck O tubes and driers so long as pump is still pumping and can just not work well or at all till a system is pretty well trashed. All the items need be either cleaned or replaced if not cleanable via cleaners then blown out dry - just compressed air.

Then on to adding oil as per a whole procedure of charging a system thought ready to be charged.

Doesn't seem like much of any of that happened so nothing was fixed and items not serviceable new or not no good for re-use right away.

----------------------------------

The fix for most even VERY handy people is to send A/C work out to those who have both all the necessary equipment plus training and really helps to have lots of experience with assorted failures of equipment, the systems. These people with that level of skills are worth a higher hourly rate than other occupations, less than some, more than some - such is life. The equipment is nasty expensive so like about anything each customer is slowly covering those overhead costs such that it ends up costly to the customer.

Naturally people like to save money and even like doing their own work. This part of the vast automotive repair trade is costly to do and mistakes can easily make it cost more than the problem it needed anything so a tough area to "tip toe thru the tulips" if you will to save money AND have lasting results.

Now, what do you want to do? Get help with more knowledge and equipment to help if you can at all. Buy all the things you need, rent some possible and take a try yourself. It's that or do what people do, send it to a shop already equipped to do this work and pay the price of their investment to know how.

Trying to be concise and failing badly at that as this is always involved.

A horrible failure about A/C problems with vehicles is that products are still boasting things that aren't true and the web isn't full of such wonderful info a lot of the time on a lot of things but somehow trusted way too much IMO.

That unfortunately motivates folks to try then find out it's a whole trade to understand and know AFTER vailiant efforts with mixed up info, lack of hands on help for a first time really hurts too and the costs go up and nothing gets fixed.

You choose what's available to you. The site has tons of info listed up top to learn from and a few techs still here for this type personal suggestions and opinions. Speaking for myself can easily misread what was asked, misunderstand a description, make plenty of typos and be misunderstood back to the person asking in this case YOU.

Where do you wish to go. There's not start to finish understanding I know of via the web to learn all this stuff from scratch,


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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Wed Jun 22, 2016 9:51 pm

The wifes car was blowing warm. After I charged it, the system started blowing sub 40* and is working fine. I didn't mess with a her car just to test the vacuum pump if that's the impression I gave.

As for the truck, I guess i'm beat. I already have an appointment with a local guy that was recommended by every mechanic I stopped at. I appreciate all of your time and effort to help me out.

Still hoping this problem all comes back to the fan clutch being bad. The STAR scan should tell us that in just a few minutes. I'm not sure if your explanation of the compressor failing and sending junk through the system was a general knowledge lesson, or if you think that's what i'm dealing with??

The dry nitrogen was mentioned by corn binder earlier in the thread.

As for the vacuum pump mist. I don't understand why I would see steam while pulling on the truck, no steam while working on the car, and then steam again when going back to the truck. I'm at a loss here.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Tom Greenleaf » Thu Jun 23, 2016 3:57 am

Tired - Sorry.

OK: Vacuum pump. You should be able to vacuum out just a manifold gauge set alone without a vehicle to see it pull max vacuum in seconds plus that empties your gauges of air and the hoses.

A compressor is a pump. The #1 reason for a failure to cool is still low refrigerant charge. That in turn if a slow leak will stop flow of oil to compressors. It' s a Domino effect. One even normal paced leak over some arguable amount of time as normal loss of refrigerant once compressor is running dry is already making a mud then can make metallic shards that cannot be flushed out effectively with current condensers the way the flow goes thru them isn't a straight line passage for efficiency works well but intolerant of debris.

A condenser could be made new with a fleck of debris and work just not up to full expected/engineered capacity and go un-noticed indefinitely just written off as a system that isn't as powerful as another - perhaps the whole life of the vehicle?

If you owned a vehicle from new and needed a replacement condenser during your time with it you just might (quite rare) find the repaired system works better than it ever did new and wonder how that could be. It was proven here at this site when a tech here cut open a condenser and found just that on a car owned since new.

Here's a decent YouTube of cutting open an automotive condenser and why they don't flush out or tolerate debris..........

Take this guy with a grain of salt - some would label this guy entertainment up to a total joke but this one I just watched is actually valuable to see what I'm trying to explain, (it's just ~ 4 min.)

https://www.youtube.com/watch?v=U0O1mcnwjZs

Problem is stated by this guy too. One problem cause the next such that partial repair is outdated and leads to what I've said you fail again taking out the same new parts trashed again and again.

It's near impossible to really know the exact condition of a condenser of anything like this efficient type. In fact just now searching the web for something even close to what I'm trying to explain just yielded a few demonstrations and explanations that were dead wrong and remain on the web as long as nobody takes them down!

Good grief, you have to know a boatload about HVAC basics to even know what is correct info or not.

I'm trying as best I can. There's just so much to understand it's overwhelming,

Tom

(edited later) Just watched that again. It's still good info and video but this genius called the condenser an evaporator in the video! Yikes - can't even get the term of a part correct and it's watched by zillions of people!
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Fri Jun 24, 2016 6:51 pm

Tom, It is a possibility that my condenser is clogged. I have only put 20k of the 160k miles on my truck, so I have no idea if any AC related parts have ever been changed. After checking the Orifice tube, I saw no signs of "black death" or metal shavings. I don't see any symptoms of a weak compressor on the manifold gauges either. So while I appreciate the knowledge, I don't think I am looking at a compressor replacement at the moment.

This website provided a good explanation of how to diagnose a system using manifold gauges. Not being an expert, I don't know if all of the info is true, but it seems logical to me with their explanations. http://www.agcoauto.com/content/news/p2_articleid/257

I realize that there is a lot to learn, but every system on every vehicle requires a lot of learning to become an expert. I feel like I would be hard pressed to find someone even half as knowledgeable as you here in small town Enid, Oklahoma. I just don't think most "professionals" care enough to fully understand AC unless they are an HVAC guy. I might have better luck asking the local residential AC repair man if I wanted someone that could for sure diagnose the problem correctly without throwing parts at it. Seems like most mechanics these days just bolt new parts on until the problem goes away, I can do that myself. These reasons are why I like to do my own work, and try to understand how things work. I realize HVAC is a profession, and one that requires as much knowledge as most others, but If I can fix my problems now, and in the future, my time spent is worth the money i'll save.

I Still think the fan clutch is my main problem. There is a good possibility that a secondary problem exists. If so, I will have to wait until after next Wednesday to test.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby cornbinder89 » Fri Jun 24, 2016 10:34 pm

refrigeration vacuum pumps can't pull a full vacuum. Some of the better two stage pumps can get close, most single stage pumps will not get much below 28". Water doesn't boil until 100 deg F at 28" vacuum. That is why if the system is known to be very wet, it is recommended to use two "sweep charges" of dry nitrogen to get as much moisture out as possible.
If you had a laboratory grade vacuum pump that could pull down to torr values, than you wouldn't need to worry.
In most cases (all but the most "wet" systems) a simple one time evacuate and charge is fine, what miniscule amount that remains is handled by the desiccant, and what you are really worried about is air or non-condensables.
If you are seeing "steam" or "smoke" I would venture you have a good leak that is pulling enough air thru the vacuum pump to bring a little of the pump oil out with it.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Sat Jun 25, 2016 9:44 pm

corn binder,

Your explanation of a leak causing more air to flow through the pump and take oil with it makes sense. The only issue I have with that theory is the system appears to be holding pressure fine. I wouldn't consider my system to fall into the category of "wet" the only water in the system would have come from the humid air while the system was open to replace the liquid line and accumulator.

This is quite frustrating to say the least. Hopefully the mech. I am going to on Wednesday has some good knowledge about this stuff.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby cornbinder89 » Sat Jun 25, 2016 9:59 pm

I wonder if you have a compressor shaft seal, that will seal ok under pressure but allows air to pass under vacuum? I had one once that did that, If you shut the pump off it would slowly loose vacuum, but was next to impossible to find under pressure. I bet you will find if you work it long enough that it will leak under pressure also, just not as fast.
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Tom Greenleaf » Sun Jun 26, 2016 11:17 am

Valid point and a maybe: Just note anyone who has watched a tire, especially leak at the rim/rubber seal under pressure but leak at low pressure (soapy water test) and then seal when filled up? Problem is still there.

Anything sealing pressure the forces are one direction and sealing vacuum the other.

Note: Full vacuum at seal level is only sealing OUT 14.7 PSI not holding IN up to 350+ PSI for moments.

Off the wall: Not holding vacuum is also frequently the hoses and hook up and all that seals that too not always the vehicle,

T
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Re: '06 Dodge ram 5.9L warm idle/short cycling

Postby Kfred513 » Sun Jul 03, 2016 10:53 pm

Update:

Tom, I did test the manifold gauge set to see if they would hold vacuum and they did. I ruled out the possibility of them leaking by doing so. I'm sure many people don't test them, and think their system is leaking, when in fact the gauges are the problem. Also I think you guys are right about the compressor shaft seals. I explained more below.

I hate unresolved threads so I will post my current situation. The Mechanic I went to could not confirm a faulty fan clutch because the compressor would not come on. He told me it was the clutch causing the problem. So that's why I lost all AC about two weeks ago. I'm not surprised because the clutch got noticeably louder when it would engage. It made a click/hiss sound, kind of hard to put words to the noise it made.

I was a little mad that he didn't use his scanner to test the fan independently of the AC system...that was my whole reason for waiting a week and a half to take it to him. I stopped by Napa on the way home and bought a Compressor and installed it right away. Put the vacuum on the system and saw no "Steam" from the pump. I had high hopes, and within minutes had 26in/hg showing on the gauge. I did a quick density altitude calculation and found out that it was 3650' MSL at the time....near perfect vacuum for the conditions. I let it run for about a half hour, then shut the pump off and watched the gauges for another half hour. The needle never moved, so whatever my issue was last time was in the compressor, or the seals where the lines come in.

I refilled the system with 134a and carefully purged the line before each can went in. I weighed everything and the system is about 0.5oz over full, which I'm not worried about. The AC is very cold now, but The high pressure side still goes up over 450psi at idle. The garden hose on the condenser immediately causes the high side to drop. I finally found a PDF service manual and ran the fan clutch diagnosis and the drive circuit ohm'd out bad (open connection) when it should have more than 10ohms resistance.

I ordered a new fan clutch this morning and I assume it will solve my issue. I also want to point out to all Dodge 5.9 owners and site admin, the electronic/viscous fan clutch in the 3rd gen diesels has a bad reputation. My truck never threw a code and it should have. The new compressor came with a Warning sheet saying if the compressor clutch went bad, the fan clutch is probably also bad, which will ruin the clutch in the new compressor if ignored. I took the old compressor apart and there was nothing left of the friction material. It was however, in great shape internally, clean oil, no black, no metal shavings, nothing to Suggest I would need to replace the condenser.

Hope this helps someone in the future. My free advice is, If your AC stops blowing cold, shut it off. I have been using it as long as i'm above ~15mph, any less and I shut it off. I turned $350 in parts into $650 in parts real quick.
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