500E a/c problem
07-06-2010, 01:52 AM
#1
Junior Member
Thread Starter
Join Date: Aug 2009
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
92 500E
500E a/c problem
My 92 500E's a/c works fine at first start but after about 30min to an hour the air isn't cold anymore. Then the next day it's the same thing - works fine when you start and after a while no cold air again. Freon level is fine. Mine is the dual-zone climate control with 2 thermostat wheel knobs. I also notice that after it malfunctions, the red lights on the 2 center buttons (EC & air recirculation) stop working. I was wondering if any of you have experienced this kind of problem.
07-06-2010, 10:31 AM
#2
MBWorld Fanatic!
Join Date: Dec 2006
Location: So Cal
Posts: 1,907
Likes: 0
Received 2 Likes
on
2 Posts
92 500e, 95 E34 525I Touring
Though your levels may be fine, it might be time to flush completely and refill. I understand that freon does lose its cooling capabilities over time.
07-06-2010, 10:41 AM
#3
If you Absolutely sure your freon levels are OK....R134a is a little picky when it comes to pressures...
Two possible issues:
1) Your vacuum pods have developing leaks allowing outside air to sneak in.
2) Your push-button control unit has solder cracks in the board
I would definitely check the pods first. Remove the glovebox and you will find the main vacuum pod unit with (7 IIRC) vacuum cables going into it. Use a mityvac and check for vacuum on all of them. My bet is a few of them are toast. It does require removal of the dash which is a few hour job, but it's not as bad as everyone makes out. IMO.
Two possible issues:
1) Your vacuum pods have developing leaks allowing outside air to sneak in.
2) Your push-button control unit has solder cracks in the board
I would definitely check the pods first. Remove the glovebox and you will find the main vacuum pod unit with (7 IIRC) vacuum cables going into it. Use a mityvac and check for vacuum on all of them. My bet is a few of them are toast. It does require removal of the dash which is a few hour job, but it's not as bad as everyone makes out. IMO.
