Post Number: 644
|Posted on Saturday, 14 February, 2015 - 03:11 pm: |
My car has developed a rough idle when Drive is engaged. The idle is fine in P or N and drives perfectly well. The problem shows itself when waiting at traffic lights. The idle can seem quite lumpy and a little disconcerting. If I put the car into N the rough idle goes away. I suspect it may be the engine mounts. Could anyone confirm this or give any other ideas as to what may be causing the problem.
Post Number: 1367
|Posted on Saturday, 14 February, 2015 - 10:54 pm: |
What happens if you're in gear and just rev the engine slightly 50rpm extra?
Post Number: 645
|Posted on Sunday, 15 February, 2015 - 06:42 am: |
Increasing the revs by 50 - 100 on a hot engine does help a lot. Here is some more info. The car runs as it should when cold. Ambient temperature was 63F (17C). At the first corner at the end of the road I live in there is no lumpiness to the tickover at all. RPM on a cold engine at idle is 656-660 rpm with D engaged, brakes applied. It is only when the engine comes up to operating temperature the engine starts to run badly. This is particularly noticeable on tickover with D engaged. The engine revs are also much more variable (629 - 645). The solution to this problem is obvious - remove the thermostat (JOKE). I'm moving away from my original thought of engine mounts and wondering if I am running far too rich a mixture. I'd appreciate any advice.