Cause of Engine Vibration When Idling?

[smartdriver 49]

My 2005 Coupe with 75,000 km which I haven't driven for a while has a distinct vibration which you can even feel in your seat and in the shift lever when idling at 800 RPM.

 

I smooths out, however, when a bit of throttle is added.

 

Not being a car guru, I was hoping to get an opinion on what it might be. Two uneducated suggestions are motor mounts or missing on one cylinder at low RPM.

[smart142 605]

Is the tach bouncing?

My guess one poor injector.

[smartdriver 49]

Thanks for the tip. Clever thought.

 

The tach is steady at 800 RPM when idling.

 

I was curious if any one of Canadian Tire's fuel additives would be an asset to cleaning the injectors?

 

Any suggestions?

[smart142 605]

If the tach is steady then the next uneducated thing to check is the motor mounts.

[Ravk 2]

Run a bit of Moly injector cleaner.  On a nearly empty tank at temperature, add a full bottle.  Drive about 50k at high speed (on the ring road called Anthony Henday here in Edmonton) then fill the tank.

This stuff can act as a solvent and clean out your tank as well, so expect to replace the filter after 2 or 3 tanks after treatment.

 

Also check if the little rubber bumper thingy is still on the muffler.  I know this seems dumb, but that actually is a vibration dampener and is noticeable when you forget to put it back on.

Edited November 16, 2018 by Ravk