More vibrations

[bullockandrew]

Hello,

My '99 SL320 auto started to vibrate when stationary in park, neutral or drive. When in park or neutral, the engine seems to be hunting a bit (the tach needle moves up and down slightly) and the car physically shakes from time to time. When stationary in drive, the vibration can be felt through the brake pedal and through the steering wheel.

Maybe I own a diesel version (!!), but it never used to do this. Had the mounts changed by AMC London - genuine MB parts and just had the plugs changed along with a B service. No change and nothing showing up on the diagnostics. The only other thing I've done is to put some cleaner in the fuel to see if an injector might be blocked.

Two additional things have been mentioned; coil pack (but I am told that would light up on the dash) and a throttle return actuator. Hmm.

Anyone have any ideas?

 

[television]

I had the same car and year, and that engine is used on many models.
Coil packs will not turn any lamp on in the dash, also the would show up on normal driving as the engine would miss, is it the same both hot and cold

 

[bullockandrew]

Hi,

The vibration goes away in normal driving, although I can feel it at a very slow crawl. It's the same hot or cold - feels like a diesel at idle.

 

[jberks]

Try changing the plug leads. Solved it on my 240 twice. (same V6 twin spark engine basically). Same symptoms by the sound of it. Ran perfectly, no warning lights, but idle just not right.

 

[bullockandrew]

OK - thanks. I'll try changing the leads.

Does anyone know what the symptoms would be like if the coil packs were playing up?

Thanks.