siyan

Anyone get a intermittent vibration / misfire on cold starts at idle?

M273, 2007 CLK550

Intermittent being once every few seconds perhaps. Goes away when driving. Doesn't seem to affect high RPM performance, so I don't think its bad gas?

betrezra

Hook your car up to STAR DAS machine. You can get one from china for low $$$$ <$500 - $600 for pc of mind. There are stored faults, and system tests you can do.

GL>

Glyn M Ruck

Some likely causes are, plugs, from not running in the self cleaning range sufficiently, an ignition coil, bad airbox to MAF seal leaving the MAF hunting to correct fuel trim, a vacuum leak or a throttle body actuator acting up. Some actuators chatter & require replacement. TB actuator trouble never shows up on a Star.

If this is mainly a town car that does too many short trips I would start with plugs. When last were they changed?

Good luck!

imimike

Hey Siyan
Iam having the same vibration on cold starts i was wondering if you solved it out yet?

vsix

Just do a small vid, load it up on youtube and then post it in here, maybe you dont have misfires, maybe your V8 just shakes a little because of wornout motor mounts....just do a lill vid of the enginebay so we can see and hear whats going on.