A/C not blowing cold...need recharge?

[BS05ZHP]

Hey guys,

My 95 M3's air conditioning is no longer blowing cold. I just realized it b/c it's warming up here in Texas.

I can hear the fan clutch/compressor kick on so I'm pretty sure I just need a R-134a recharge. I can still feel a *hint* of cold air coming out.

Can I take my car anywhere for this? I'd rather not go to the dealer. Is there anyway for "non-BMW" techs to screw up on this?

Thanks,

Jeff B.
95 Cosmos M3

[Hestola]

If you haven't already done so, replace the microfilter. It made a HUGE difference in my car!

[BS05ZHP]

Any way that would block all the cold air?

Thanks,

Jeff B.
95 Cosmos M3

[Hestola]

Probably not. Unless it has never been replaced. You should have seen how completely nasty mine was!

[JamesM3M5]

You need AC gauges to accurately determine what is needed. It could be a clogged drier, low charge, worn compressor, etc. If the compressor runs for a minute then cuts off and comes on every few seconds afteward, you are probably just low. You should find out if there is a leak if you keep having to charge the system every year. UV dye in the oil will show moderate leaks, but a CFC sniffer will find even the tiniest leaks.

If you want to buy a set of R-134a gauges, expect to pay about $80-100. There is a high side and a low side. The high side should run at 210-230psi, low side around 22-28psi.

H/S press...L/S press...Possible cause(s)
high............low.............clogged drier, clogged exp valve, exp valve stuck shut
high............high............overcharge, poor airflow over condensor
low.............high............worn compressor
low.............low.............poor refrig flow, low charge

JamesM

[BS05ZHP]

Thanks for the info James.

I just looked at the fuses and all looks well. (based on other M3's where the auxillary fan was not turning on because a fuse was shot)

Jeff B.
95 Cosmos M3

[BS05ZHP]

Hey James,

Do you think the best approach is to self-diagnose this?

Do you think I would be better off taking it to a shop? I'm mechanically "able" to do this, just wondering your thoughts. I'm wanting to fix it myself, but don't want to get in over my head. Not to mention that the Bentley has the standard "ac refrigerant must be replished by a certified technican" even though when they started putting R134a in cars they became "user-serviceable".

Thanks in advance!

Jeff B.
95 Cosmos M3

[Bernman]

Take it to any shop that does AC service. In this respect, there is nothing special about BMW. I had mine recharged last summer when it was displaying the exact symtoms that you describe. It works great now. The guy at the repair shop said that it is normal to need a recharge after 5 - 10 years. I think it cost me $45.

AC is not something that you can diagnose/repair without special tools.

You should also replace the interior air filter (microfilter) occasionally. This will really help the airflow, and *is* something that you can do yourself. Check out Stygar's site for a great how-to

Good luck!
Bernman

[JamesM3M5]

Originally posted by 95Mpower
Do you think the best approach is to self-diagnose this?

Unless you have several old cars, it's not worth your time or money to diagnose the A/C system. Now if a shop says you need $1000 in parts and labor, take it to another shop for a second opinion. If you find that it really is a $1000 problem, then you may want to try to fix it yourself. Specials tools/equipment include a refrigeration vacuum pump ($300-600 or rent one), gauges ($100), and a good DIY book on AC systems. I got all of my AC knowledge from http://www.acsource.com when I was trying to fix the R134a retrofit in my 88 M5. They even have a message board with several helpful AC techs that answer questions. Don't bash penguins, though.

But as I said, if you only need a recharge, any AC shop will diagnose and refill for under $80, probably much less than that, too. If you need a drier, too, that will take about 1.5-2 hrs labor to evacuate, replace, evacuate, recharge. http://www.alloembmwparts.com sells the drier for $70, list is $170. The shops should reimburse you for the mass of refrigerant they are able to recover from your system. If they take out one pound, make sure they don't charge you back for that pound when they put it back in. It's only about $5-10/lb, but it was yours to begin with.

Do it soon, because the shops get busy in the spring once everyone realizes their AC died over the winter!

Run the AC for a few minutes every week to keep the seals lubricated through the winter. This simple act saves costly repairs in the future.

JamesM