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Author Topic: 2001 Monte Carlo A/C not working  (Read 4888 times)

Offline vince

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2001 Monte Carlo A/C not working
« on: March 22, 2008, 03:43:03 PM »
Hi everyone.  It has been a while since I have been on here.  I have a couple of issues that hopefully you can help with.  I dont see many A/C questions on here, maybe you are didicated to engine mechanical.

My 2001 3. 4 Monte Carlo has 148,000 and I have kept up with the maintenance over the years so it is not in bad shape.  I recently purchased a new HHR Panel so the Monte Carlo does not get driven as much.  I still drive it once a week or so but when I drove it the other day the A/C did not work in it.  It was working fine the last time I drove it.
The fan still works on all speeds as well as the defrost settings, floor, vents, etc. 
I have also checked the compressor and the clutch still engages and still kicks on when turned on and does not short cycle like it would if it were low on R-134. 

Also I am losing a little bit of coolant somewhere.  Not real bad but I cant find the leak.  No drips on the ground or around the engine that I can find.  I have let the car idle to heat up and turned it off to check all of the hose connections to no avail.  I have replaced most of the heater hoses as well.
I replaced the radiator about a year and a half ago and the water pump about 7 months ago.
I can smell the coolant sometimes from outside the car and seem to smell it more in the car.  I thought maybe the heater core was leaking but I cant find any evidence of coolant inside the car.

Any help with either of thes issuess is greatly appreciated.

Offline Gus

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Re: 2001 Monte Carlo A/C not working
« Reply #1 on: March 22, 2008, 06:01:12 PM »
More than likely the intake gaskets are leaking....usual place for the coolant to collect, is under the throttle body, in a depression in the top of the block, next to the dummy distributor shaft...another place is under the p/s pump, and the corner of the head of #1 cylinder.....sometimes, the leak is internal, also......but check all hoses, w/p weep hole, and condensate drain from the heater core....

You say the compressor runs? Then grab the A/C lines and see if they are cold....if they are, you have a temp door issue....if they are warm, you are low on freon and possibly have an A/C pressure sensor problem....

Offline vince

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Re: 2001 Monte Carlo A/C not working
« Reply #2 on: March 23, 2008, 06:21:48 PM »
Thanks Gus.  I will check the areas you suggested for the coolant leak.  I did replace the intake gasket about 70,000 miles ago.  (what a job that was) It may be time to do it again I suppose.

You may be correct on the low freon suggestion.  I took the car out for a little run yesterday and left the a/c running.  It tried to cool, never got hot in the car with the windows up, about 75 degrees outside.  I did check the lines and they are not cool or sweating.  I will have the freon level checked this week. 
Do they have something to seal a small leak or do the seals have to be replaced?

Offline Gus

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Re: 2001 Monte Carlo A/C not working
« Reply #3 on: March 24, 2008, 05:25:15 AM »
If the compressor was running, the first thing to do is put a set of gages on the vehicle, and see how this compares with the reading from the A/C pressure sensor in the PCM, then check what the pressures are with the compressor running.....

The only way to know the EXACT ammount of freon in the system is to recover by weight.....If low, then there is a leak and it has to be REPAIRED.....

Offline vince

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Re: 2001 Monte Carlo A/C not working
« Reply #4 on: March 26, 2008, 01:55:43 PM »
I put a guage on the system, the small one you buy at Autozone.  It shows to have good pressure, about 31 psi.  I dont know how accurate these guages are.  The hoses are warm but it does try to cool.

Could the compressor be going bad? It does not make any noise or short cycle.  Gus mentioned an possible a/c pressure sensor problem.  Can this be replaced without replacing the compressor or draining the r-134?

If I have to take it to a shop I will, I just usually do all of my own repairs but dont have much a/c experience.

Thanks again, Vince

Offline Gus

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Re: 2001 Monte Carlo A/C not working
« Reply #5 on: March 26, 2008, 04:37:50 PM »
31 psi? High or low side?

You need to read both sides, to see if the compressor is actually working......

If that reading was on your low side, then at rest pressure should have been close to ambient......you say it was 75 degrees, it should read about 75 psi....if the engine is hot, it should read even higher.....so let's say your low side is 80+ psi....you turn the A/C on, and it drops to a steady 30 psi....if it did that, then that low side line should be cold to the touch......

If the pressure is 31 psi, with the compressor not running, you are definitely low on freon....

Offline vince

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Re: 2001 Monte Carlo A/C not working
« Reply #6 on: March 26, 2008, 08:34:19 PM »
Sorry Gus, not sure if it was low side or high side.    Only one little hose with this set with a guage in line.    The gauge on it shows the psi within color ranges.    The hose would only fit on one connection.    The smaller fiting next to the firewall.    This is the hose that runs between the compressor and evaporator.  
On the guage it read in the blue @31 psi which indicated the level was o.   k.    The pressure reading was with the car running and engine warmed up. 
I should probably just take it somewhere to have it checked properly but I am always afraid they will try to sell me more than I need.  
Thanks again, Vince
« Last Edit: March 26, 2008, 08:37:30 PM by vince »

Offline crunch

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Re: 2001 Monte Carlo A/C not working
« Reply #7 on: March 27, 2008, 11:52:55 AM »
If you are going to fix it yourself get one of these.
http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=DIY

Them wal mart one hose kits are killers kits.
And do not use any of that leak seal any oil cans from wal mart type stores.

Get the proper equipment to do the job or If not look around for a good repair shop that you can trust.

Check around Ask around
Word of mouth.
Family friends coworkers neighbors business people and delivery people.
Mailmen and parcel delivery people get around and notice a lot of stuff.
Even a good parts house knows what shops are good and not good.
Chamber of commerce and better business bureau and city hall.
If you find a good referral to a repair shop go look them over and talk to them.
Look for a clean looking busy place with nice people running it.
Ask a few questions and ask about their qualifications and training.
Not all places have trained tech/mechanics.
 If they do not find a place that does.
Even all dealers do not have all trained techs/mechanics.
Crunch

« Last Edit: March 27, 2008, 11:56:45 AM by crunch »
OEM parts only hurt one time Crunch said that.
Cheap after market stuff will bite you many times. My brother in law is learning that the hard way.

Offline crunch

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Re: 2001 Monte Carlo A/C not working
« Reply #8 on: March 27, 2008, 11:58:49 AM »
Wal Mart DEATH KITS

You cannot properly and safely recharge an air condition system with them.

The one side stop and go gauge does not tell you what your system is doing or is over charged or undercharged.
A overcharged or malfunction air condition system can reach over 500 lbs of pressure.
Enough to blow up that can or system and freeze you at first and the burn you or blind you and if any propane /butane in there blow and light you up.

The stop leak crap and who knows what kind of oil in the kits there will stop your system for sure.
Just like pouring super glue in it.
And some kits even contain freon with a butane mixer.
 Good for a big blast.

If you are going to do it do it right and safe.
Here is what you need to start with.
http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=RefrigerantGaugeSets

In the older days you could just throw in a can and go.
But over the years just adding freon is getting harder to do.
Newer systems have to have the correct amount of freon down to the ounces.
Most will need pumped down and vacuumed down and the right and amount of oil and a set amount freon charge installed to get the air to cool right and the system to last.
If an air condition is low there is usually a leak that needs fixed and also a lose of lubricating oil from system.
Also air and moisture enters a low system
If you are going to try to do it get the proper type air condition gauge set with the low and high side gauges.
Hook up the gauges and get a reading with compressor running at idle and at 2000 rpm on the high and low side.
Post back pressure reading and we can help you.
Crunch





OEM parts only hurt one time Crunch said that.
Cheap after market stuff will bite you many times. My brother in law is learning that the hard way.

Offline brcidd

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Re: 2001 Monte Carlo A/C not working
« Reply #9 on: March 28, 2008, 08:17:46 AM »
Your car uses a V-5 compressor- a variable stroke NON-CYLING system by design-- it will never cycle- even if low on refrigerant- the compressor runs and can only pump what refrigerant is available- it is a very durable compressor mechanically- but it can't cool without enough refrigerant- 

The number one a/c failure mode in automotive systems is loss of charge due to a leak- your most likely leak location in your system is the compressor shaft seal- that single lip teflon seal was changed to a double lip design in the 2002 model year.  - so- is there oil slinging out from the front of your compressor?  does the "belly" of the non-painted compressor housing appear oily?-  the only true method of determining refrigerant charge is to extract the refrigerant and weigh it as mentioned earlier

Offline vince

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Re: 2001 Monte Carlo A/C not working
« Reply #10 on: March 29, 2008, 07:12:27 PM »
Thanks for the info everyone.  I do not see an oily residue anywhere.  One of the first things I started looking for.  I think I am going to leave this up to the proffesionals.  I do alot of my own repairs but I do not know enough about a/c systems nor do I have the tools.  I will let you know how it comes out.

 

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