I have a 91 325ix with 228k. This is an extra car that doesn't get driven that much. But during the early summer, my car started having issues cranking over. In fact, I could only crank it over while giving it gas. Once it was running, it ran like crap with rough vibrations and idle surging - i would have to keep giving it gas to run.
I replaced the basic stuff like worn plug wires, distributor and cap, spark plugs, clean icv, replace afm, and few brittle vacuum hoses. There appears to still be a vacuum leak as i can hear a whistle at around 2000 rpms. But for the life of me, cannot find the exact source. i plan to remove the intake manifold and throttlebody to replace gaskets, etc.
So even after the above replacements, the idle was still crap. I did a compression test to find out the sad truth.
compression was 150 - 125 - 75 - 75 - 125 -150.
I did a leakdown on the bad cylinders are got na - 130 - 100 - 100 - 130 - na. so not sure if that means i have major worn rings or if compression loss is from somewhere else.. also i did the compression test with a cold engine with all plugs removed, 7 full cycles and full throttle.
Not sure if i entirely trust the compression tool either because its a used snap-on i got off of ebay, but it looks like a head gasket issue and some worn piston rings and maybe needs a valve adjustment.
When i crank over the engine and let it run for about 10 minutes, the engine warms up and the idle smooths out and runs without applying gas pedal.
My question is, if my compression is indeed shot, with the horrible compression numbers above would engine warm up expand enough to maintain a normal-ish idle or is part of my idle issue some faulty sensor like the engine temp sensor?
I also want to add that the oil is clean and the coolant is clean. and the exhaust does not smoke. Prior this this idle issue, the car also didn't burn oil.
I replaced the basic stuff like worn plug wires, distributor and cap, spark plugs, clean icv, replace afm, and few brittle vacuum hoses. There appears to still be a vacuum leak as i can hear a whistle at around 2000 rpms. But for the life of me, cannot find the exact source. i plan to remove the intake manifold and throttlebody to replace gaskets, etc.
So even after the above replacements, the idle was still crap. I did a compression test to find out the sad truth.
compression was 150 - 125 - 75 - 75 - 125 -150.
I did a leakdown on the bad cylinders are got na - 130 - 100 - 100 - 130 - na. so not sure if that means i have major worn rings or if compression loss is from somewhere else.. also i did the compression test with a cold engine with all plugs removed, 7 full cycles and full throttle.
Not sure if i entirely trust the compression tool either because its a used snap-on i got off of ebay, but it looks like a head gasket issue and some worn piston rings and maybe needs a valve adjustment.
When i crank over the engine and let it run for about 10 minutes, the engine warms up and the idle smooths out and runs without applying gas pedal.
My question is, if my compression is indeed shot, with the horrible compression numbers above would engine warm up expand enough to maintain a normal-ish idle or is part of my idle issue some faulty sensor like the engine temp sensor?
I also want to add that the oil is clean and the coolant is clean. and the exhaust does not smoke. Prior this this idle issue, the car also didn't burn oil.