Well here's my experience. I have a 1993 325I with a 5 speed. I purchased the car about 1 1/2 years ago. When i bought it from the original owner i noticed a small surge in the idle when we started it, but it went away when the car warmed up. When the car had about 98,000 miles on it the surge began to almost stall the car. Only when the clutch was depressed. Found out my T.O. bearing was bad. Took the car in and had the clutch , T.O. bearing and the pressure plate replaced. While the car was appart the mech said there was a service report on the flywheel. They should also be replaced. So $1450.00 later everything was fine car runs good and doesnot stall. Still had some surge, summer gets here and when i start using the ac the surge gets a little worse. And the ac compressor makes a funning noise when the ac clutch kits in. Checked the pressure in the ac system it was about 65psi. Used a ac gage purchaed at A.Z. Releaved the pressure by slowly purging the low pressure side down to about 42psi. AC ran fine for about a week and ac clutch make the same noise again. Checked pressure and it was up again. ( must have air in the system when it gets hot it expands??) Purge it again and it's been fine ever since and really cold. Any way i still have the idle surge. It's beginning to annoy me so this is what i did. I increased the idle to about 750rpm using the idle set screw on the throttle body. And began using premium gas again. It took acouple of days for the computer to reset but NO MORE SURGE! Been holding steady at 750 rpm no surge at idle with or w/o ac on. Well that's my 2 cents, hope it helps someone
