Hello! I have a 2004 R53, I just had a local shop replace the ac compressor, unfortunately due to a crack I noticed when attempting to just replace the coil on the end. They also checked the ac system for leaks after install and everything was good.

I did do a few things on my own before doing the ac compressor, coolant flush, new radiator thermostat and expansion tank, as the previous owner had put stop leak in rather then replace the radiator. No oil or coolant leaks.I also had Llumar CTX heat blocking film installed all the windows to get the car as cool as possible as living in Las Vegas we are upwards of 110 often this time of year. so I feel like the car should be in the best shape for good cooling.

The questions I have are, What temp should I expect to get from the vents with it set to low for temp? It is not as cold as I would have expected the air to be. Its cool but no where near as cold as my all original parts 88 Mercedes, which was a surprise with the age difference between the cars. Also when set to recirculate the air, the volume of air from the vents is greater however it doesn't seem to be a noticeable difference in how cold the air is. I would like to know thoughts on what to look at first to solve that problem, and I am not sure where the air gets pulled from in the cabin to check if something is blocking that inlet.

Than you all in advance for the assistance.

 

Cold should be cold! Is there enough liquid in the AC system? It might also be a good idea to let it be pressure tested. The system needs a refill from time to time btw

 

Condenser/drier problem maybe, particularly if they're original. O-rings are another suspect point as you may have freon leakage at the hose connections. I replaced the compressor/condenser/drier on my '04 and it will freeze you out of the car.

 

+1 on the dryer / condenser if they are original

are you losing pressure?

 

If your AC system needs a refill from time to time you have a leak and that needs to be addressed. Freon does not go bad or break down in a closed system. No I'll give you that the compressor oil may break down though.

 

I had the shop install a brand new compressor, and recharge the system as well as pressure test, they said everything checked out fine. Other then new freon and compressor all other parts of the system are original.

 

After the a/c work you had done, your system should be creating/blowing interior air between 35 and 48 degrees depending on the outside temp. If your shop didn't test that they're derelict. Take it back and ask for answers.

 

Picked up a thermometer I can stick in one of the vents yesterday and took it for a drive. In the day it was 110 out and at the coldest the air coming out of the vent got down to about 70-75 if the car was moving, it went up a few deg stopped. Took it out after the sun went down and it was about 90 deg.it got down to about 50 deg. I did notice when I turned off the AC that it had a bit of a musty smell.

 

110 will certainly make your system work hard. I'm in Texas so I understand. Still, your interior air should be cooler even at that high external temp. It could be the drier that removes moisture from the air which makes it colder. Replacing that would require a whole new evac/recharge. I would still take it back to the shop and ask for advice. Another pressure test might be in order to discover if there has been a leak since replacement. Honestly though, since it's a 16 year-old car, I'm surprised they didn't want to replace the condenser/drier when they did the rest of the A/C work .

 

Does the invoice say how much refrigerant 134a they installed? Should be 14.6 +/- 0.4oz by Uncle Bentley. If they pooched that up, this would be the easiest thing to address.

Mildew in the evap coils and/or the vent ducts. Quasi-normal with most cars as they age. There are products that can help address it but the first thing is to check and make sure the condensate drain tube is clear and you're getting the characteristic puddle under the car with the AC running. Probably not a big one in Vegas area but should be a steady drip there. If it's clogged the condensate can stay in the evap box and turn it into a swamp. This won't address the sub-par cooling problem you're having but it might head an even bigger one off at the pass. Evap R/R requires a dash removal. Shocking for a car this small, I know.

 

How much was the air compressor replacement? I was quoted $1700 from a local shop in my town.

 

$1,700 is highway robbery. At the outside a new compressor should cost no more than $400. A rebuilt compressor with a 12-mo. warranty can be had on eBay for ~$100. That's the route I went while also purchasing a new condenser/drier combo on eBay for another ~$65. Replacement is straightforward and it will cost another $100 to evacuate/recharge your system. My new setup works perfectly fine (too cold in fact).