I recently did a head gasket on my 2.0. I had the head shaved 11 thousandths because it was warped, got a 3 angle valve job too. Ever since I put it back together my car idles pretty bad. It's alright when it's cold but then as it warms up it gets worse until it warms up to 170 degrees then it's fine. The car runs fine at any speed but idle. I checked my cam timing and it was a tooth off, I corrected it and the problem got better but still didn't go away. I replaced the coolant temp. sensor and the oxygen sensor (it wasn't working properly) but that didn't help either. I've checked my vacum lines about 78 times now so I doubt that is it. A few days ago I went and talked to the machinist who redid my head and he told me that it was a re manufactured head and had been resurfaced at least once before, maybe twice. He also told me that because it's an overhead cam when the head is shaved it shortens the space between the camshaft and crankshaft sprocket and that changes the timing slightly. I guess that the 11 thousandths he took off was too much. That makes me thing that it's probably the timing that is messed up. It's a little too late to put a shim under my head, so I wondered what I could do to remedy this problem. I've seen adjustable cam sprockets before, but I can't seem to find one for a 1994 2.0. Does anybody know where I could get one or what else I could do to fix this? This car is driving me crazy, any help would be greatly appreciated
You can't outrun the radio.
Im not sure if milling the head down would only effect the timing when its warm. What it might be is you block is slightly wrapped also and when it heats up it makes a small gap and loses compression. Other thing to look at would be did your old head blow the gasket if so you may have bad bearings in the bottom end <honestly not sure if that would cause it either though>. one othe possiblity would be you may have a crack in your head somewhere. To me it sounds like a lose of compression somewhere when its getting hot but doesnt make sence it stops afterwards.
I don't think that I'm losing compression because anything besides idle the car runs fine. The car also runs fine stone cold. I can beat the heck out of the thing and it runs just fine as long as it's not idleing. What also leads me to believe it's timing is that I was a tooth off, and now that I've got it timed right it got better. If I was leaking compression then nothing would help except for the temp. It might have been a little confusing before so here is how it goes: Cold start it starts and idles fine, I drive for 2-3 minutes and stop at a light and it idles rough but runs fine as soon as I give it a little bit of throttle. Then as soon as the temp reaches about 170 my idle smooths out. The old head gasket blew because it had one 5 months ago and the head bolts were reused and the loosened up. They were probably only 30 foot pounds tight when I took them out. This warped my head over cylinders 3 and 4. I have a steel block so i doubt that it is warped, not impossible but doubtful. I don't think the bottom end sustained any damage because the gasket broke between cylinders 3 and 4, I was leaking compression not coolant. I think the reason that it is alright cold and warm is because the computer uses different ignition timing during those times. The problem is that my car is distributor-less, so I can't adjust the ignition timing myself (and I don't know if that would even help anyway.) I'm looking for an adjustable cam sprocket or a program that can change my ignition timing.
You can't outrun the radio.
I have ran into the same situation with my 98 Cavalier Convertiable Z24.
Exact same symptoms, Although the heads were not rebuilt, And a compression test was performed right away the next day after symptoms started. Compression test showed the expected results for the model.
And as 94 Red Bird mentioned ....
Quote:
The problem is that my car is distributor-less, so I can't adjust the ignition timing myself
i also have the same problem.
So im staying tuned on this post to see if anyone has any input on this problem.
