rough idle

[m3dren]

couple days ago my e30 started idling higher than normal. around the 1000 range in neutral. it idles at 600 when i first start the car. but once i start driving and it warms up a bit it goes to 1000. the engine causes more vibrations as well throughout the car. most noticeable through the shifter when in neutral

and just last evening the oil light lit up. i had an oil change just last month and i also checked the dipstick and it was at a good level. turned it on again and drove about 20 miles home and it never lit up again. could this be related to the weird engine idle? not entirely sure why it lit up in the first place

could it be an icv issue for the rough idle? because around june of last year i had a bad icv that made the car idle at 3000 in neutral but we swapped it out with another one to fix the problem. haven't had a problem since but i'm beginning to think it could be the same problem

i know the details are vague but any input is very much appreciated. just want to catch issues before they get bad

thanks in advance

[jlevie]

The most likely cause of the the idle problems will be intake leaks and a sticky ICV. The ICV can be removed and cleaned with carb cleaner until the vane moves freely. A smoke test of the intake will tell if/were any leaks are. You also need to check the TPS to make sure that the idle switch is working with a meter or test light. The idle switch should close when the throttle arm is 0.030-0.060" off the idle stop screw.