i just picked up an e30 too, all the research i did i basically found that noone has a perfectly running m20, mine still burps once in a while, it was pretty bad before i bought it. mine has a new icv in it, and cleaned some plugs and sensors and whatnot
Mine only wanders up and down when warm. I removed the icv plug but it only exaggerated the problem. My coolant also surges in the reservoir parallel to the rpm surges. I'm worried it's a bad headgasket.
The first thing you should look for is vacuum leaks.
Has your coolant level been dropping as you drive the car (i.e. is the level when the car is cold lower than it was yesterday when the car was cold)? Is there oil in the coolant or coolant in the oil?
Coolant surge in the reservoir could be caused by air in the system. Try bleeding the system to see if there's any trapped air.
What's the best way up bleed the coolant? I'm used to cars with a cap on the radiator. With the e30 reservoir and the shape of the upper rad hose it wouldn't seem productive to jack the nose in the air.
Hey Quinn, been a long time. My other username is krgoodwin if you don't recognize this one.
I had a similar issue with mine. Turned out my idle screw was cranked in so far it brought the TPS out of idle. Sounds like yours might be a coolant issue but the TPS is something else to check.
Linear Mode
