Air Conditioner Anomaly

[BostonGreen318]

Greetings! A rather perplexing thing happened on the way home from work today. I had fresh, cool air blowing through the central air grills when I noticed that the A/C, recirculated air, and rear defroster push button lights activated on their own.

Any attempt at shutting the indicator lights off proved futile although eventually the rear defroster light turned off on its own accord.

Minutes later, what appeared to be vapor and would soon transform into foam began seeping/spitting out of the air grills above the thermostat panel. This eventually stopped five to ten minutes afterward.

Upon arriving at my final destination, I opened the hood and heard a sort of high pitched metallic buzzing and saw a spinning belt wheel from what I believe to be the A/C compressor.

My question is whether or not anyone is familiar with this type of issue and what can be done about it. Any help or advice would be immensely appreciated!

[C Sean Watts]

Originally Posted by BostonGreen318

Greetings! A rather perplexing thing happened on the way home from work today. I had fresh, cool air blowing through the central air grills when I noticed that the A/C, recirculated air, and rear defroster push button lights activated on their own.

Any attempt at shutting the indicator lights off proved futile although eventually the rear defroster light turned off on its own accord.

Minutes later, what appeared to be vapor and would soon transform into foam began seeping/spitting out of the air grills above the thermostat panel. This eventually stopped five to ten minutes afterward.

Upon arriving at my final destination, I opened the hood and heard a sort of high pitched metallic buzzing and saw a spinning belt wheel from what I believe to be the A/C compressor.

My question is whether or not anyone is familiar with this type of issue and what can be done about it. Any help or advice would be immensely appreciated!

Your evaporator has a hole in it. The oil and refrigerant came out. The lack of oil did not make the compressor happy. At a minimum you'll need a new evaporator and receiver/drier and a set of O rings around the system. It will need to be flushed clean. There is no way to know for sure if the compressor is gone until it's taken off the car and flushed (if any pieces of black chunky stuff or metal comes out it's not good.)

[BostonGreen318]

Sean, I appreciate your reply and apologize for the delay with my response. Lately, I've been juggling quite a few mechanical and repair issues with the 318, more specifically, the sunroof, air flow meter and, of course, the ongoing A/C debacle. I'm currently driving the car without the use of any air circulation whatsoever, for it seems the car is unable to blow even fresh air through the vents.

I'm grateful for your advice and don't discount the recommendation you've provided but I thought I'd try some other options before taking the car to a technician. Considering what you've advised, I can only assume that a trained and certified technician can perform any A/C related repairs. So, being the stubborn (and cheap) SOB that I am, I figured I'd do some research before relinquishing the reigns over to a mechanic. In doing so, I have discovered that some of the previously mentioned anomalies that the car's cooling system have exhibited are quite common for the E36. In fact, there are a few websites claiming that the 'Heater and A/C Control Head', aka 'Climate Control Head' or 'CCU' may be the culprit.

Opting out of repairing the original unit itself (which I understand is a rather easy fix if you know what you're doing), I managed to find a similar pre-owned rotary-knob head taken from a '94 325 at a reasonable price online. I decided that to be completely thorough, a check of all fuses and relays associated with the climate control system was in order. Those turned out fine. Unfortunately, following the installation of the '94 CCU the only noticeable difference is that the A/C, recirculation, and defrost indicator lights now glow accordingly. Still no actual airflow being forced through the vents. Another curious aspect is that the compressor seems to be having difficulty spinning?!?

I realize this further illustrates the strength of your argument that the evaporator has a hole in it. Before I venture off to the mechanic however, is there any possibility that the problem is related to the Blower Motor? I read an article on a website (http://www.dvatp.com/bmw/diy/hvac_blower/) that suggests that this may be another potential answer to this ongoing dilemma. Thanks for your time and patience.

[C Sean Watts]

Sounds like you have more than one problem going on.

No CCU display and/or random fan blowing = bad CCU
Good display with little or no fan = blower regulator (called "final stage" in the catalog) w/ good blower

Neither would make foam come out of the vents. If your car uses R134a you can get everything you need to repair over the counter BUT it helps to have a manual. R12 (pre ~1996) and you'll need an EPA certification.

[Big Evil]

Could also be your evap blew and took out the control unit. You really need to get into the evap case and see what went wrong.