Join Date: Aug 2008
Feedback Score: 0 reviews
possible misfiring, but no check engine light?
I have a 2002 H4 with 4-speed auto and it has 142,000 miles on the clock. The only major work it has had is the head gaskets replaced a couple of years ago, and an O2 sensor 3 or 4 years ago.
In the last week it has started what I think is misfiring. This happens as I apply throttle from idle, generally when I'm stopped and then pull away, or if I coast into a corner and accelerate out. It is worse the harder I accelerate.
It feels like the engine splutters and stumbles for 2 or 3 seconds, and is then fine. The check-engine light is not on, and has only come on once, yesterday, when I floored it in the snow (gotta have a little fun). Then the check engine light flashed for 3 or 4 seconds and then went out.
A couple of times when it has done it badly under heavy throttle, there's been a 'clunk' sound from the engine. I guess this is a backfire?
I assume because the light isn't on that I can't scan for a code (?).
Any ideas on what's really likely going on, and what I can do to fix it?