Originally Posted by tmshokie

I recently replaced my engine mounts with Anchor products. I had a really bad rattle/vibration in gear while stopped. All my mounts were blown/leaking.

Since replacing the mounts I still have some vibration, though better. Waiting to see if "break in" is an issue. At the same time, mine seems to be connected to a rough idle now. I can see my block vibrate and pulse. This was NOT the case before I changed out the mounts. The car idled smoothly.

I guessed it was a tune-up issue (50k on the NGK plugs). Replaced the plugs and found oil in the 5th combustion chamber. Lots of oil. Plug was completely covered from the threads down. I researched and have new valve covers and gaskets on the way. Hoping that's my issue.

So to my question:

I think I buttoned everything up correctly when I did the mounts. I only took off one wire harness which was under the air filter, so I could get the driver side mount out. I'm wondering if I might have done something in the process or knocked something loose, causing this problem.

The rough idle can best be described as a "pulsing." tTe engine idles okay for about 2 sec and then it shudders (feels like it wants to stall but not completely), then idles okay for 2 sec, then shudder (on and on and on). This happens in gear but is worse when I put the car in neutral.

I figure a combustion chamber filled with oil would mean that piston is not firing = ergo the oddly timed pulse. However, I find it really hard to believe that it didn't do this before I changed the engine mounts. Could I have done some damage lifting the engine during the repair? I used the trans bell housing as my lift point.

No lights or codes showing up. Gas mileage is down so something is amiss. Performance seems okay - no noticeable power loss.

Don't want to keep chasing rabbits if there is something obvious I am missing. Thoughts?

P.S. I did not replace the front mount with a electronic mount. Dealer told me that was not necessary. Curious if that would/could be the culprit.

Originally Posted by mikeyen

Sounds like a loose plug wire to me. I had the same issue. I can't guess which wire it might be.