E 36 M3 AC Woes.

[Kurt Sampara]

I have a 97 M3 and was wondering if I could charge the AC myself??? The AC is able to keep the cabin cool on a hot day but seems to warm up when idling until I hit a bump then I can fell cool air again??? The car has had one owner and it was only serviced at BMW until I purchased it two years ago. I have not really used the AC in the past as the car has been a back road stormer and then back in the garage. But now that fuel is so expensive, I have been using it during the summer as my daily driver. Sorry for the rant. The AC compressor makes some noise @ idle, so I am hoping it is from to little R134, also I am going to change the belts. Any advice will be helpful. Thank you in advance. Kurt.

[Jeron]

Does the front fan come on when the AC is on?

[Kurt Sampara]

I does not come on when AC is on. But car does not overheat, and thermo. stays right in the middle? Any suggestions? Thanks.

[coolbear1]

I don't know about the bump thing, but,d oes your 97 have a sight glass on top of the reciever dryer?
The sight glass is no larger than a pencil eraser, and would be located on top of a tank, between the front of the fender well, and the driver side head light.

If you find it, Clean it good, use a flashlight, and see if you can see any bubbles when the car is at idle. It should be totaly clear. check it idling and at about 2000 rpms.
If you can see the freon moving through it, at any rpm, it indicates low charge.
If it is low, and you charge it yourself, don't make the common mistake of overcharging it.
Too much is worse than not enough.
Stop adding refrigerant as soon as the sight glass is totally clear.
Drive it and check it again.
Add a little if needed.
Hope this helps,
Good luck