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Chrysler 300m woes

brucebotti on Sun June 29, 2008 10:07 PM User is offline

Year: 2001
Make: Chrysler
Model: 300m
Engine Size: 3.5L
Refrigerant Type: 134-a
Ambient Temp: 80
Pressure Low: 20
Pressure High: 200
Country of Origin: United States

Hi,
I am having trouble with my wife's 300M. The A/C was working, but it was making funny noises which I thought was the clutch. I disconnected it for a few months, and now when I hooked it back up, it makes a constant growl. Even with the readings above, which are on the low side of normal, I get no cooling at all. Both sides on the compressor are warm. Shouldn't I at least get some cooling? I had my wife switch the A/C on and off, and it does engage. Does it sound like I have a blown compressor?
Thanks,
Bruce

Chick on Sun June 29, 2008 10:31 PM User is offlineView users profile

You could have two problems, both appearing at the same time. Is the growl there with the ac off? Then a pulley, not necessarily the ac pulley, can be bad, remove the belt and feel the pulleys, all should turn freely. The other problem "could be" that you are undercharged, have air in the system etc..Once you determine the AC pulley bearing is OK, have the system evacuated and recharged to factory specs. (add a little oil, PAG 46) That is the only way your going to know you have a full charge. Then you can properly diagnosis the problem of cooling..

-------------------------
Chick
Email: Chick

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

Freedoms just another word for nothing left to lose

mk378 on Sun June 29, 2008 10:54 PM User is offline

Do the condenser fans work?

If the system is properly charged and has those pressures you should get some cooling.

Noise which occurs only with the compressor engaged is usually coming from inside the compressor. You can try adding some oil but if the noise persists, a pre-emptive replacement should be considered. Driving until the compressor completely fails will generate a lot of debris which will complicate repairs.

brucebotti on Mon June 30, 2008 8:01 AM User is offline

It only makes the noise with the compressor engaged. But it is a constant growl....when engaged.

I'm leaning towards replacement. What else would you replace at the same time? I know that I need to change the Receiver/Drier. How about the Expansion valve? Also, would I need to order an "O" ring / Gasket set, or do the new compressors normally come with them?

I am going to bring it to a Ford Dealership after hours where they told my cousin, that he can take out the old 134. I will install and then charge it since I have the gauges and a good vacuum pump.

Thanks for your help!
Bruce

bohica2xo on Mon June 30, 2008 1:07 PM User is offline

Growling, no cooling, low side pressure below spec...

You will be needing One of These in all probability. The primary filter in that car. If the compressor has started to spit junk into the system, it stops in the condensor passages.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

brucebotti on Mon June 30, 2008 8:56 PM User is offline

Thanks everyone! It looks like compressor, receiver/drier, and condensor to change for sure. Should I also change the expansion valve? Should I buy a gasket/"O" ring set, or do they come with the replacement parts?
Thanks,
Bruce

bohica2xo on Tue July 01, 2008 2:33 AM User is offline

The TXV is usually fairly tough, you can inspect it for corrosion when you open the system.

The O ring set is always handy to have when you open a system, there is always some connection you did not expect to open...

As Chick pointed out, there is a possibility that things may be in better shape than I suspect. If the vehicle is a second car, you could treat it as an IRAN (Inspect, Repair As Needed), and recover/charge/test to minimize the parts cost. On the other hand, if this is a Saturday job & she expects to drive it to work monday morning - the condensor replacment makes the most sense. With a 120 buck condensor, I can't spend much time testing or flushing one - that may need replacment anyway.

I have never had a compressor "growl" with pressures in the low end of the range that was not dying. Since you are going to recover the charge, measure it & see where you are at. My book says you should have 28 ounces of 134a in that system. Check the discharge port & line for debris when you open the system. With a 7 year old system & compressor noise, you should have some fine metal particles in the discharge line. If you have bigger pieces (sugar granules or larger), then the condensor is highly suspect. You may be able to repait it for less, but if I had to fix a 7 year old car with a noisy compressor it would get a compressor, condensor, dryer & TXV - I just hate to see one come back.


plan on flushing the hoses & plumbing while you have it apart. If you flush the evaporator, amke sure you get all of the flushing agent back out. Use a solvent that dries quickly, and plenty of clean dry air. If the hoses have no mufflers, some mineral spirits & plenty of air should do the trick. Clean & dry is the goal.

A fresh oil charge, vacuum test for leaks & evacuate before charging should put you back to OEM performance.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

brucebotti on Tue July 01, 2008 1:07 PM User is offline

bohica2xo,
Thanks to you and the others for the advice. Since my wife just has to have her car (she can't be away from our first grand baby for more that a few hours), I will plan on changing the compressor, receiver/drier, expansion valve, and condenser. I hate to do things over, so I'll try and do it right the first time.

On the PAG oil, is there a special one for my application. AllData says PAG ND-8, but I don't see anything like that on the site.

Thanks,
Bruce

bohica2xo on Tue July 01, 2008 6:14 PM User is offline

ND-8 oil is ISO 46 viscosity, so a good DEC PAG 46 should be fine.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

brucebotti on Tue July 01, 2008 8:07 PM User is offline

Thanks again!
Bruce

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