recharge the AC?

[berndt]

I have a 92 325i convertible. Looking through the old service records I see a receipt for a r134a recharge. I don't however see a receipt for a 134a conversion. I doubt a conversion has been done. Is there any way to definitively tell?

Also, the A/C doesn't work very well (if at all). Should I just try and recharge it with 134a again if the conversion hasn't been done? Can I refill with r12 after it's been filled with 134a (can you still even get r12)?

I have a feeling I know the answer to all these questions (convert to r134a properly). Thought I'd ask around first.

[jeffnhiscars]

You can't mix the refrigerant or the oil that each one requires. If the external valves have adapters on them it's a pretty sure bet it's been converted. A receipt specific to your car for a charge of r134 is also a pretty strong indicator.

If you can get your hands on some nitrogen that can be used to pressure test the system before you start spending money. If it's empty, put a vacuum pump on it and find all your leaks, then charge it and see how things perform.

If you don't have the tools and experience you may want to have a pro diagnose it...cheaper in the long run than guessing and throwing stuff at it.

[roguetoaster]

It's likely that a '92 was converted when near new.

To check either look for a sticker in the engine bay, or look at your pressure switch on your receiver drier and check if it's one wire or two going to the connector. One wire, cleanly installed probably means that it was a factory job.

If you wanted to get more involved you could look at the expansion valve and check the p/n to see if it is a 134 or 12 unit.

[berndt]

Cool. Thanks guys. I'll do some poking around.


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[c0rbin9]

It's likely that a '92 was converted when near new.

To check either look for a sticker in the engine bay, or look at your pressure switch on your receiver drier and check if it's one wire or two going to the connector. One wire, cleanly installed probably means that it was a factory job.

If you wanted to get more involved you could look at the expansion valve and check the p/n to see if it is a 134 or 12 unit.

By '92 all pressure switches were combo high/low, with single wire, right? It would have come with a combo switch from the factory.

I'd be looking at the fittings, as jeff mentioned.

[berndt]

Well the compressor very clearly states r12 only.


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[jeffnhiscars]

Well the compressor very clearly states r12 only.


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The only e30 compressors that do not have r134 compatible seals are from production between 7/87-10/88 (+ or - a month or 2) not counting IX and M3. All the others will tolerate 134

[ThatOneEuroE30]

Also just letting you know. There is no such thing as just needing recharged. AC is a closed system like a cooling system you don't just loose coolant for no reason. If your ac isn't blowing cold you have an issue. Could be clog somewhere or a leak in the system.

[berndt]

Cool. There is an adapter on the refill valve. I'm going to assume it's been converted for now, which is great. Luckily, the weather is getting colder, and it's a convertible, so there's really no need for it anytime soon.

Thanks for the help!

[berndt]

Also just letting you know. There is no such thing as just needing recharged. AC is a closed system like a cooling system you don't just loose coolant for no reason. If your ac isn't blowing cold you have an issue. Could be clog somewhere or a leak in the system.

Yeah, I had a feeling about that. I'm not surprised at all though, it's an old car. It does make the potential repair simpler though.

[htseng]

The only e30 compressors that do not have r134 compatible seals are from production between 7/87-10/88 (+ or - a month or 2) not counting IX and M3. All the others will tolerate 134

Unless you have the last of the E30s. Mine is a '93 vert with 9/1992 production date. It came with R134a from the factory.

date


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[Economy Sport]

Also just letting you know. There is no such thing as just needing recharged. AC is a closed system like a cooling system you don't just loose coolant for no reason. If your ac isn't blowing cold you have an issue. Could be clog somewhere or a leak in the system.

You got that right! My nonworking original R12 A/C on my '86 hadn't been touched in at least 20 years, but still had positive pressure in the system. I haven't had a chance to diagnose why the compressor and auxiliary fan don't come on, but when I applied direct voltage to the compressor I saw white bubbles in the sight glass which went away after a couple minutes. With the auxiliary fan not running and the interior blower at 2nd or 3rd lowest setting, here's the vent temperature (with the outside temperature approximately 75°).



For shits and giggles I got my online EPA 609 CERT, and while I'm hardly an expert on the subject, it's a big no-no to put R134 on top of an existing R12 system. And a proper R134 conversion must have the R134-specific red and blue quick release connectors, as well as a decal in the engine bay replacing the original one for R12. Not sure how you would go about properly (and legally) evacuating and vacuum testing the system, as the few shops that still handle R12 won't touch a car that's been contaminated with R134, as it will ruin their equipment.

[berndt]

Well I added a can of r134 to the system today. It's a 92 vert, and based on past service records, it's very likely been converted (possibly from the start). Anyway, I now have cold air! We'll see how long it holds. I don't need A/C that badly, so it's just a perk if it works.


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[Das Delfin]

I was gonna say, best way to recharge the A/C is with the battery ;)