AC makes car Idle funny [Archive] - SaabCentral Forums

: AC makes car Idle funny

26th March 2007, 10:42 PM
I was hoping someone could shed some light on this for me...

When I bought the car (Feb) the PO told me that he had the AC serviced last summer and it worked great. Since we had our first "warm" day, I finally got a chance to test out the AC. It seemed to blow only slightly cooler air wich was dissapointing (I assume it's lost it's charge), but the strange thing was when I was sitting at an idle with the AC on, the engine would rev up and down between 2000 and 1100rpm every 10 seconds or so (Normally hovers around 1000) and would almost stall out when the revs dropped. Is this normal???

26th March 2007, 10:45 PM
It could be as simple as the wrong proportion of Gas. It would be wise to st art with a total drain then a perfect fill to spec. Also failed hoses and clamps in this sealed system can easily leak gas.

27th March 2007, 01:23 PM
Perhaps a messed up charge of the AC can cause this anomoly.

Find out the owner's definition of "serviced"..:cheesy:

I'd clean/oil the IAC and look into the vacuum lines.

<The trouble with knowledge is that the more one has, the more one realizes how little he has...>
an old Vietnamise proverb

Eric in Lockport, N.Y.
27th March 2007, 08:22 PM
these guys are right, I would'nt even run the AC anymore until you have it serviced. There could very well be WAY too much R134a in there and that could possibly cause some strange things to happen....

28th March 2007, 12:00 AM
Thanks guys,

I won't play with my AC anymore until I figure out whats going on... I don't want to wreck it! Is there anyway I can test the levels of R134a in the system myself?

I did replace all the vacuum hoses last week - they were pretty bad before... I was pretty pleased with the results; the car ran a little smoother after and my MPG jumped up by 2-4 ( Now able to get 34mpg on hwy!!!) I haven't touched my IAC though I did see a bit of black stuff on the edges of the valve when I looked in. Should I clean this? and what would this do for me???

28th March 2007, 12:40 AM
No, as far as i know you can't check the level of the R134a. in fact if you are new to working on cars i wouldnt even touch it, it can be VERY dangerous if you dont know what you are doing. i would take it back and ask him exactly what he did.