My AC system is charged up to specifications with the appropriate R134 freon.

However, the car is cooling very marginally ( I have measure the temp at the front vents and it is in the mid 50 degree F range when the car has been in the shade).

The expansion valve and evaporator were both recently replaced.

The car has 98,000 miles on it and the original compressor - I s it possible that the compressor is beginning to fails and thus resulting in marginal cooling?

I am at my wits end - the dealer is telling me that everything is up to spec.
Obviously, the dealer just doesn't want to fool with this problem ( or doesn't have the experience to properly diagnose it).

Often air conditioners are judged by the difference between the ambient air and their discharge.

If I remember correctly 30 - 40 degree drop is pretty good, because the ambient air gets cooler as time goes by.

I just tested my '95 850 and got a difference of 40 degrees. When my dealer tested it, the technician recorded 37 degrees. I was told that it passed, but I did not ask what their guidelines were. (After reading posts at brickboard for several months, I suspect that for many dealers, the standard is whatever they think the customer will accept!) BTW using a drop of 35 degrees getting a reading of 37 would be a reasonable number in a garage that is kept around 65-70 degrees.

You could test a loaner or take one of the dealer's new or used cars for a test drive and see how your car compares to the dealer's.

--
2 8s & 2 7s 600,000 miles total

I guess I'm at a loss here. You say everything is up to spec as far as the pressure goes. No loss of fluid, you are fully charged up. You measured temps in the mid 50's. Ok...what temp do you think is correct? What was the ambient temp inside the cabin and outside? Is the blower not blowing strong enough?

If you're getting good pressures, and no leakage, then your compressor isnt going bad. R134 isnt known to be as cold as the old R12. I dont know about you, but I dont like to drive around with my interior in the mid 50's, that's pretty cold.

Right. I think the temperature dial only goes down to 60 degrees, doesn't it?
So 50 degrees sounds pretty darn good. I'd leave it alone and start driving!

kevin

Yes--the only way to tell if the system is working right is to hook up a low pressure and high pressure gauge respectively. That will give the proper idea of what is happening.

Also, it's possible that the climate controls are malfunctioning and causing heat to get through to the passenger compartment, destroying the cooling ability of the A/C system.

The best way to start is to see if the system is making appropriate pressure.
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Chris Herbst
1992 745, 68k

And others:
93 944, 150k
90 245, 110k
88 744, 160k
87 245, 185k

The system is making good pressure.

As I previously mentioned, the evaporator, expansion valve and drier receiver were all recently replaced with oem parts by dealer.

Took it back into dealer and was told pressure and system was OK.

It is not cooling adequately or as before - as measured with my thermometer in dash for ten minutes plus.

What else can it be? As you suggest, perhaps the heater contrl valve may be sticking, I will look.

Any other thoughts? Does the pressure test rule out the ac compressor?

If they're being honest and they checked the high pressure output, then yes, the compressor should be good. This is IF the charge and replacement parts were all executed properly.

There was a good suggestion about the condenser. A clogged condenser is almost useless, and is a common problem (I often overlook it).

Also, if the heater valve check and the condenser inspection don't turn up anything unusual, it might be worth the money to have a cursory inspection done by a reputable A/C shop. I know of one A/C shop in my area that does fantastic work at about 1/2 price of others. There are usually a few great places like this in any major metropolitan area. Ask around a little bit, but first see if the other suggestions might shine some light on the situation.
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Chris Herbst
1992 945, 71k
Volvo shop tech

Have you tried to clean out the cooling fins on the condenser behind the front grill? if they are full of bugs and dirt, this will cause a decrease in cooling temps. I actually just replaced my condenser about 2 weeks ago (because of a leak, due to a minor front end acc)I replaced the condensor with an aftermarket one for 139.99 and recharged the system, the AC is much colder now than before, and it was properly charged before the accident so the R134 is not a factor in the new increased cooling just the new condensor.

I have cleaned theese off before on other cars (1983 244 turbo,etc) and have noticed a sinmilar effect in better cooling.

if the condensor is full of bugs and dirt then not as much air will flow through it causing a dcrease in cooling.

Clean it out with some good soap/bug tar remover. and take it for a drive and see it it helps. hte best part is it is bassically free to clean. soap and water is cheap.

Dan

If the dealer you are using will not get your system to cool to volvo specs, it could be that they did not do their job correctly in the first place. If you can push them a bit harder, or if there is a "good" service dept. in your area use it.
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Steve F. Hoboken, NJ