Cost to replace the AC evaporator?

[edlvrt]

My A/C is starting to blow warm, again. A month ago I went into an indy shop and they added half a can of refrigerant, but she is back to her just cool air from the left vents and warm air from the right vents.

While under warranty, the PO brought her in 3 times with A/C complaints. This was a red flag during purchase, but not a deal breaker. First time (June 2009) they evacuated and recharged. The second time the car was in (April of 2011) BMW replaced the evaporator. The car went back to the dealership this January, but everything checked out OK.

I haven't had them check it out this second time yet, but worst case, I guess the evaporator is bad again. Any idea on how bad this could drain the modification account?

So far my family is 0 for 2 with BMW evaporators. My E36 and my mom's E83. They say everything comes in threes, right?

[telijah]

I always forget, but that's the one behind the dash, right? The part itself is not terribly difficult, its just a pain to get at since you have to take the dang dash out.

I would first take it to a proper a/c shop that can do a proper check and sniff out the leak.

[static667]

Go to a mechanic that is good with A/C work. I highly doubt that the evap. coil would be bad a second time. Have you looked into the condenser coil having a leak? Get someone with a leak detector to figure out where the problem is coming from.

[edlvrt]

I will have it checked out soon, just haven't had the time yet (and we finally got our first cold front yesterday). I figured that the evaporator is essentially the worst case scenario in terms of cost as the entire dash needs to be removed to get to it.

[telijah]

That's definitely true. Also, a good point to look for leaks is the service ports themselves. I'd get an evac/recharge, and in 4 months was blowing warm again on the passenger vents. After the second recharge, they put the dye in it, and immediately saw it pooling under the cap of the service port. Was a quick and cheap fix, other than the $100 bucks for the evac/recharge.

[zj96sc]

Yeah, you need to properly diagnose. A set of decent manifold gauges is pretty inexpensive and will give you an accurate picture of what's going on. A lot of things besides just a refrigerant leak can negatively impact A/C performance. If the pressures are indeed low again, you've at least confirmed a leak rather than throwing parts at the problem. Then add dyed refrigerant yourself or have a shop evac and recharge with dyed refrigerant and find the leak. For in-dash (evap) leaks you can use a R-134 sniffer. More often than not leaks are at fittings, crimps, or in the condenser (since it is most exposed to road debris).

The one A/C system I've troubleshot (shooted?) fully DIY from warm air to frequent recharges required to full on 100% rock solid 40F vent temps, the culprit was a bad crimp in the high pressure line. Found it while moving the A/C compressor off the engine to swap the timing cover on the engine.

A/C work is voodoo-ified by many but it is work you can do yourself. The only thing you can't do is empty the system yourself (legally). For what you're going to pay a shop to fix this, buy the refrigerant, evaporator, o-rings, line disconnect tools, oil, and vacuum pump and you'll still have tons of money left over. Then, have a shop professionally evac your system. Go home, open it up, swap the component, pull vacuum, verify vacuum holds, and recharge with cans to the proper amount. There should be charts somewhere that tell you how much oil to replace depending on the component swapped.

If you're concerned about a "proper" recharge (by weight), skip buying the vac pump and just bring the reassembled but empty system to a shop and let them pull vacuum and recharge. Only problem here is if she doesn't hold vacuum you're out the labor to find out.

For me this is like almost everything else in auto maintenance - give a fish/learn to fish.

[edlvrt]

Not to drag an old thread up from the dead, but I brought her in yesterday to have the A/C checked and it was determined that the leak is from within the dash area. There goes any mod money for 2012.

[danewilson77]

Damn. Sucks. Should you get a second opinion?

[edlvrt]

I don't see the need to. I've been going to this mechanic for years and he has never steered me wrong. There were no visible indications of any leak in the engine bay, no hit on the UV dye, and he showed me the freon/refrigerant sniffer going off while testing the vents. So, new evaporator and expansion valve. The parts aren't too expensive, but the labor is the kicker as the entire interior has to come out. Thanks, BMW.

[telijah]

Dang, I saw this thread bump up and thought "I bet it is the evaporator". Sucks man. You gonna do it yourself, or just have them do it?