1992 735iL Air Conditioning problem

Refrigerant leaks out. Garage put tinted refrigerant in about two months ago. It's gone again and very hot in Southern California. Obviously, there is a leak. Before I go back there and spend a buttload of money having them find the leak, has anyone had any similar E32 AC issues? Is there one point that the leak is found most of the time? Also, is the 1992 E32 running R12 or R134?

In 93 they started chaning over all the cars to R134 so your system might be R12. If you wana spend some money get it converted over to R134. Before I bought my caddy it was done to it. Funny thing is it says on my evaperator that it can run on R12 or R134.

Any idea how much it costs to switch over?

Ive never priced it or had it done but I did see a kid that had a 87 nissan 300z buy a 40$ part that went on his compressor and it switched him over to R134. Try going to a local parts store, advanced auto, pep boys, auto zone ect and see if you can get a price on it. Just explain to them what you want to do and Im sure that they will help you out.

The leak-dye they installed when they serviced the system will show up using 'black-light' and the inspection of the system should be included in the price you paid [ I assume the system was empty and they tested with an electronic detector and couldn't find the leak then....sometimes I assume too much]. This recheck only works on visible engine room components but is very effective for slow leaks, when you can see them.
The most common 'unseeable' leak is the 'Evaporator' inside the heater box and those are easily tested with a 'sniffer'. replacement requires removal of the glovebox, cover panels, firewall cowl cover for pipe access and removal, but it's not a difficult repair and if your quoted more than 5 hours labor....shop elsewhere...........jb

Wow! Thanks Jeff! I'll print this info out and take the car down. Is it possible to replace the evap myself if that is the problem? (I dont care about the time involved, I love tinkering with my Bimmer)

Thanks again!

IF that's the cause of the leak, YES, you could do it yourself, BUT, you need a fairly good selection of small hand tools and some time like you said.

THE problem is recovering the freon that's probably still in the system [it's probably R-12 & expensive as you've discovered], then having it properly evacuted for at least 45 minutes and recharged, though this could be done by a shop.

IF IT'S the evaporator, I'd recommend replacing the
Expansion Valve AND the Receiver/Drier.....the expan. valve will be in your hand anyway and they do fail, and the Desecant [the drier component] of the Receiver becomes staturated with exposure to the atmosphere over time.....keep me 'posted'...jeffb

Ok, yep it's the evaporator!

Just got the call today and of course, an offer to do the job. Check this out: $450 for an Evap, $850 for the labor. HAHAHAHAHAHAHA!!!!!!!!!!!!

Guess what? I'm going to learn a LOT about AC by doing this myself! I found evaps on Ebay for MUCH less than $450, not to mention the one on Bavauto.com for only $174. The one on Ebay is only $112 and comes WITH the expansion valve. I'm planning on replacing all of the parts just like you suggested. I'll have them, or someone else, evacuate the system for me. That shouldnt run more than $75 or so.

Now, the Garage Thief, I mean owner, says "dont get an aftermarket one cause ours come with a year warrantee". I've used a LOT of aftermarket items on a number of cars, including Bimmers I've owned in the past, and have never had any problems.

Your opinion on aftermarket?

Ok, well, I have just read this (and many of the other posts re: the 7-series BMWs) as I have just purchased my first one ( a 1989 735i) 2 days ago - and the aircon is not going. The guy I bought it off said he was quoted $NZ800ish ($500 US approx) to get it fixed and there was some valve that needed replacing - which I assume is the expansion valve you refered to above Jeff?

Can you please tell me where this valve lives, and what I would expect to pay for one? My local auto-sparky said he could recharge the system reasonably cheap of it was all going so if I can get the bits myself I will, then just get him to re-gas the system - or is there a bit more to it than just replacing the valve?

Any help appreciated - I'm sure there will be more questions to come yet... damn I love this car - I'll never drive jap again... well, except my truck, but thats different :)

thanks in advance for any help

Steve

Hi Steve, nice to advise someone in New Zealand. The 'Expansion Valve' is the only likely valve in the system they might have meant. It's on the, wait, what side do you drive on? I assume the 'right' side, so your Expansion Valve is on the.......I've never looked at a 'right driver' but think most system's other than steering and pedals are the same. Look in the engine bay for the two aluminum pipes going through the firewall from the a/c compressor. The Expansion Valve will be 'behind' them, inside the car, on the side of the heater/ac box under the center of the dash board.

Access, as I've described to 'jarhed' isn't real difficult, just a bit of work taking things appart, BUT on a 'right driver' I've not a clue what it would look like with pedals and steering column in the way and might be tight, but, obviously, do-able. There will be a big plastic cover that screws to the heater box hiding it and the piping. Remove the cover under the instrument panel and have a peek. I'll be around......auto-sparky huh?....wonder if I qualify, what is an 'auto-sparky'??

Haha... yes, the right hand side - and I think you are correct as to where the rest of the stuff not related to driving the car goes... I will check and see where the pipes run through, but the a/c pump and pipes are on the right hand side of the engine bay (when looking forward).

An auto-sparky is Kiwi slang for an automotive electrician - he owns the local auto electrical shop but did his training when he was younger on air con systems. Since you know what the valve is and where it goes, and based on other posts I have read in the forum, I think you would more likely qualify as a BM Guru of all fields - just out of interest, how did you get so knowledgable about them? My expertise is in Toyota mini-trucks (we call them the Toyota Hilux) and modifying them for off-road conditions.

Anyway, when it stops snowing I'll go look under the dash :)

regards

Steve

Guess I forgot something else Steve, it's winter down there. I'm familiar with the 'Hilux' name, Toyota used it here in the states years ago, tough little trucks, used a real 'beater' of one years ago in a local 'blizzard' to get my step-son into seattle for NBA games, three old engine blocks in the bed, a set of tall skinny snow tires and I was passing 4X4 trucks in 2 feet of snow.
As far as your question about me, I've been working on BMW's over 30 years, for profit, in dealerships and getting the factory schools in Monvale, NJ, Dallas TX and L.A. CA, but would soon tire of dealership and BMW's factory practicies and technician compensation so would always go back out to independent shops, which is where I am now and found this forum by chance as a way to share what I can with other BMW enthusiasts you may 'be led astray' by other "profesionals", well meaning or not.

hope to hear from you soon, braving the snow.........................jeff b.

Well, I appreciate the assistance, its nice to find someone so knowledagble and happy to share that knowledge.

I tend to get carried away with things I am enthusiastic about, and the BM is an easy thing to be enthusiastic about, so I'm likely to ask lots of questions about it in the coming few months as I get used to it - one of which I will ask shortly in a new thread re: using the alpina 535i chip in my car.

Not snowing now, just torrential rain :P I'm still waiting for a dry spot.

regards

Steve

I shall remain on duty, for the duration of your adventure[s]......did someone famous say that?.................best to you, jeff b.............

Jeffrey, you ROCK!

Thanks so much for the help! I put some dryer and sealer in there to see if that would stop the slow leak. Seems to have worked for the time being. It's actually a little colder now because the sealer had ES-12a in it. I'm switching to Envirosafe ES-12a rather than going to r134 or continuing to purchase expensive R12. I got it from Ebay, you can see more information about it here:

http://www.btt.org/ES.html

Although, I'm sure you know more about it. Your thoughts?