Hey there. Noob to the forum.
Own a 91 525 (m50) with 242k miles. Been a great car. Bought it with 187k miles from my father who purchased it new. Completely stock--although I hate the bottlecap rims. Owned it for almost 6 years now.
Got the standard problems: headliner, LKM, door panels unglued, water pump, timing chain tensioner coming loose (and blowing out all my oil in a jiffy) etc all addressed here. All taken care of except the headliner and my most recent prob: at low speeds (<35mph and coasting toward a light, for instance), the RPM will wind down to about 1100 RPM then gently surge to 1400-1500 RPM, then back off to 1100, and back up and down etc until I put my foot on the brake which puts the idle right about 700.
Took it to an indi. He got me for some rotten hoses and a valve cover gasket. I had the plugs and on O2 sensor put in coz it was about time anyway. Said he couldn't find any vacuum leaks and would need more time to pull the head off and prowl around the guts of my beloved E34 to find the idle problem. I asked about the idle control valve and he said probably not coz the idle is smooth when stationary... it just gently surges when coasting to a stop.
I passed this up coz it was a pretty open-ended fishing expedition on my nickel.
I put a few bottles of Techron and started using Chevron Premium exclusively.
The car runs great. I ran the codes using my Peak tool--nothing.
I'm baffled. Anybody out there got a clue as to what's going on?
