190e 2.6 - A/C problem / question
 

'92 190e 2.6 - A/C blowing pretty cold when I'm running on the road, but after about 15 seconds at idle at a stop light, the cold air stops. Upon accelerating again, it cools off again after about 15 seconds.

I do alot of DIY, but I know next to nothing about A/C work. Can anyone give me an idea of what I'm dealing with in this kind of problem?

Thanks,

Most likely the system is low on refrigerant. If you're not familiar with a/c systems, you would be best served by having it done by a pro.

Good luck,

Thanks Larry,

I'm hoping that's all it is, just wanted to get a feel for the symptoms / problem.

cheers,

Don't get TOO excited. If it is low on refrigerant, then it had to go somewhere. That means there is a leak. If a system gets low over a period of ten or more years, that is somewhat normal, if it happens over a year or less, you have a leak to find and repair.

Good luck,

Actually refrigerant can leak out the compressor in the winter due to cold weather. Depending on how cold it is. Remember the compressor is always spinning when the engine is on, the clutch is not but it can leak there. Used to see it alot in Upstate NY winters. After about two to three winters you would need a refresh. Happened more often on 4 bangers. Remember also the clutch engages when the defroster is selected. So as it engages in the real cold it leaks as the seals tend to shrink in the cold.

Yes, any automotive compressor leaks at the shaft seal, but if it is leaking at a rate that requires annual charging, the leak is too profuse and must be corrected.

A typical system will lose its charge in about 10 or 12 years. If you are charging it as often as once every year or two, you should consider this a leak, find it and repair it.

Auto a/c compressors don't leak any more in the winter than they do in the summer. In fact in most compressors they are more apt to leak at the shaft seal while the compressor is engaged and cooling. You might be getting this mixed up with the fact that the compressor shaft should turn a few turns at least once per week in the winter to keep the seal in good shape.

Have a great day,

Seals shrink at a much faster rate in the -20 degree F temps than the aluminum or steal does! I have seen this on several cars that were only a year old in Upstate NY. Not so bad on ones the last 10 years but before that it was an issue. Mostly with the old refrigerant cars not the new stuff. My family used to own a new car dealership for 75 years and I did see an awefull lot of compressor's leak down the system, not totally or anything but enough that after 2 years they would need a little refresh on freon!