2002 Pontiac Ram Air Trans Am ac is not cooling properly

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Al9
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby Al9 » Sat Sep 12, 2020 8:44 am

Stuff can still lodge inside the fins and block airflow even though they appear clean. You want to see light shining through them.
dannyual320
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Location: Montgomery, TX (just north of Houston)

Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Sat Sep 12, 2020 10:47 am

Al9 wrote:Stuff can still lodge inside the fins and block airflow even though they appear clean. You want to see light shining through them.


I didn't think about that. Other than the slight amount of debris in one of the pictures that I linked in my last post, the fins all looked sparkly clean. I can try using a flashlight to confirm.
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bohica2xo
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby bohica2xo » Sat Sep 12, 2020 11:51 am

Ask yourself, how did the debris get all the way to the radiator? Through the condenser? Or around it somehow?

And A19 has a valid point. I have seen condensers clogged with gnats, while the surface is clean. I always recommend deep cleaning the fins with a strong surfactant like simple green, sprayed in to the fins on a cold condenser. Let it soak for a few minutes, then flush it with a garden hose. You may be surprised at what comes out.

Use a drop light in the engine bay at night. Get down level with the heat exchangers and look at the light coming through.
dannyual320
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Mon Sep 14, 2020 7:53 pm

Al9 wrote:Stuff can still lodge inside the fins and block airflow even though they appear clean. You want to see light shining through them.


Ask yourself, how did the debris get all the way to the radiator? Through the condenser? Or around it somehow?

And A19 has a valid point. I have seen condensers clogged with gnats, while the surface is clean. I always recommend deep cleaning the fins with a strong surfactant like simple green, sprayed in to the fins on a cold condenser. Let it soak for a few minutes, then flush it with a garden hose. You may be surprised at what comes out.

Use a drop light in the engine bay at night. Get down level with the heat exchangers and look at the light coming through.


So I spent some time over the weekend looking closer at my condenser and radiator. I took air dams/deflectors apart so I could get closer and better looks at the condenser and radiator. There is only so much that I can move the condenser while it's still hooked up to the ac hoses. Upon closer looks, there did appear to be more debris and grains of sand caught in the fins. Here are some pictures:

https://www.amazon.com/photos/shared/cXnTr0oXQkqM2ViMptdFLg.jDKptZH11crfNf1r8t2h4m

https://www.amazon.com/photos/shared/X_ruCCiaSBGzrxV8JB0f1A.7AaGfngzkk2dNRgwzx-KsU

https://www.amazon.com/photos/shared/vEVxL18-S9elGEPnCVxiJg.Fp-zGmECLvzdf_kVzZT8iN

I took your word and sprayed the condenser and radiator fins down with degreaser and let it all sit for a while then I blew it all out with the garden hose and a good high pressure nozzle. I had good strong streams of water coming through the condenser fins. It was impossible to get the spray nozzle in between the condenser and radiator but I was still able to get plenty of water shooting through the radiator fins. I'm very confident that there is no clogging or airflow blockages through the fins of the condenser and radiator. For what it's worth, my engine has had no overheating issues even in the sweltering Houston heat.

You can see in these pictures that everything came out nice and clean:

https://www.amazon.com/photos/shared/26iJQAq5RPy4MvqvNOuuqw.aui8hrvovQj-_A7PlWVEfL

https://www.amazon.com/photos/shared/5YBOGtYsSMylnIrhlPJuiA.EsO8nOiNWXZbU2mDrgcDHt

https://www.amazon.com/photos/shared/YFdMT-NTSKGvY-rKLH3RRA.B0Fu-vFEcJq_aVuDlv5smF

https://www.amazon.com/photos/shared/7n9YpTayRb-oJgJN_N8KhA.gYzbeXJhZmAPjsnINgdclU
dannyual320
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Location: Montgomery, TX (just north of Houston)

Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Mon Sep 14, 2020 8:12 pm

So today my Mastercool 69110 recovery unit arrived. I pulled a vacuum on the tank and before I recovered the refrigerant, I decided to hook the gauges up one more time and take some readings.

My car was completely cold when I started and the ambient temperature was 88 degrees.

Cold engine

Idle.................................1500rpm
H135................................H155
L32..................................L34
Vent83F............................81F


Engine warming up but still not hot

Idle.................................1500rpm
H180................................H190
L34..................................L32
Vent78F............................78F

My evacuated recovery tank had a tare weight of 17.86 lbs. I hooked up the recovery machine and recovered my Trans Am's refrigerant and then weighed the tank a second time. The second weight was 19.51 lbs. My total recovered refrigerant was 1.65 lbs or 26.4 oz and my system has a specified charge of 24 oz.

Obviously there is something wrong with the system but at least we can rule out a low R134a charge.

https://www.amazon.com/photos/shared/MKz3J7XSTmm8CkSRoWF0nA.7eQnJ7WF3gn8HGM6jxqjtl

https://www.amazon.com/photos/shared/3zlf1sNCR0-ZFg8j7PsXTQ.f2zCcG7E4w2Tt3R-6MJHXU
Al9
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Location: Southern Europe

Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby Al9 » Tue Sep 15, 2020 12:47 am

I know it sounds like a "throw random parts at it" approach (i see it more as routine maintenance though), but now that the refrigerant has been recovered you could possibly replace both pressure controlling devices - the compressor's control valve and the orifice tube. Don't know how much of a hassle it's to get to them on that vehicle, but they're definitely cheap parts.

But i still think something's wrong with your evaporator.

When you charge it up again, get as close as possible to 24 oz, or even better let a RRR station equipped professional charge it up to the specified weight. The V7 system is unforgiving when it comes to charge weight.
dannyual320
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Location: Montgomery, TX (just north of Houston)

Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Tue Sep 15, 2020 8:05 am

Al9 wrote:I know it sounds like a "throw random parts at it" approach (i see it more as routine maintenance though), but now that the refrigerant has been recovered you could possibly replace both pressure controlling devices - the compressor's control valve and the orifice tube. Don't know how much of a hassle it's to get to them on that vehicle, but they're definitely cheap parts.

But i still think something's wrong with your evaporator.

When you charge it up again, get as close as possible to 24 oz, or even better let a RRR station equipped professional charge it up to the specified weight. The V7 system is unforgiving when it comes to charge weight.


I don't think that either of them would be that difficult. I know the OT is very inexpensive but I have no idea about the compressor's control valve. I'd certainly be willing to try replacing these items.
dannyual320
Posts: 30
Joined: Tue Aug 18, 2020 2:23 pm
Location: Montgomery, TX (just north of Houston)

Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Tue Sep 15, 2020 8:06 am

Al9 wrote:I know it sounds like a "throw random parts at it" approach (i see it more as routine maintenance though), but now that the refrigerant has been recovered you could possibly replace both pressure controlling devices - the compressor's control valve and the orifice tube. Don't know how much of a hassle it's to get to them on that vehicle, but they're definitely cheap parts.

But i still think something's wrong with your evaporator.

When you charge it up again, get as close as possible to 24 oz, or even better let a RRR station equipped professional charge it up to the specified weight. The V7 system is unforgiving when it comes to charge weight.


I'm going to admit right up front that I absolutely hope that this isn't the case. I hate having to pull a dash to get to evaporators and as meticulous as I am, the dashboard is never the same afterward. Lots of squeaks and rattles :x !

Here is the reason that I currently doubt that it is an evaporator problem: ac parts under the hood are not cold. The only cool part under the hood was just after the orifice tube right before it goes into the firewall. Cool but not cold. No other cool parts and no sweating on any parts.

With my ac scale I don't think that I'd have any problem charging exactly 24oz of refrigerant out of my 30lb bottle.
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Tim
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Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby Tim » Tue Sep 15, 2020 8:12 am

Many pages of posts, which I have not read many. Are the inlet and outlet evap tubing under the hood at the case the same temp?

Don't just toss parts at it. Your pressures show you are within range. Have you checked or addressed any reheat issues? Do you know the exact amount of oil in the system at this time?
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dannyual320
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Joined: Tue Aug 18, 2020 2:23 pm
Location: Montgomery, TX (just north of Houston)

Re: 2002 Pontiac Ram Air Trans Am ac is not cooling properly

Postby dannyual320 » Tue Sep 15, 2020 11:45 am

The inlet just after the OT is cool (slightly) to the touch and the outlet feels like ambient temperature.

The oil charge is the original GM installed back in 2001 (it is a 2002 model, though.) There are absolutely no signs of refrigerant/oil leakage anywhere.

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