Hey guys,

I was having a vibration at idle or at a stop sign/light in D. It was especially worse on a uphill. So I replaced 2 engine mounts and transmission mount. (Lemforder engine mounts and Mercedes tranny mount)

I expected the vibration would be gone but no. I am still getting vibration at idle or in D. The level of vibration on steering wheel has been reduced but I can feel it on my seat and body.

Anyone had similar expereince? Or have a solution/suggestions?

Thanks,

 

Your engine vibrates at idle despite all new mounts replaced...

Can you read your engine LTFT fuel trims (lean) ?
How old are your spark plugs... (time yet) ?
How many total Miles (Cyl. wear) ?

 

Have you done an OBD scan?

 

Does it vibrate in neutral or park as well?

 

Do the scan, my guess would be ignition coils (tuneup) or the crank sensor might be on it's way out.

 

Meh, a scan (unless you have Xentry) is going to be pass/fail. Now, lets be real...this car is going on 20 years (or more) of age...we call that "Charciter".

 

If the mounts are not the problem, then the source is the engine itself. Which means you'll need to start with the basics. Spark plugs, clean fuel injectors, etc. A properly tuned engine will be super smooth. No rough idle, no misfires.

 

Isn't this a common issue? Mine does the same - It feels like either an axle issue or driveshaft - i have not figured it out yet.

 

mine does not - only in R / D - thoughts?

 

+100% exactly !

The target is near balanced cyl contributions.

 

So, I think I had this issue too. Car would have random small surging at idle, random vibrations (not all the time) but no CEL. Got the mounts replaced, still had the issue. Decided to clean the throttle body, and then realized that when I put the air intake back on; i didn't actually snap the back of the intake in place, just the front two. i suspect that because of this, once in a while there'd be a sliiiight gap in where the air intake meets the MAF shaft/hole, which would cause a little more vibration/surging. secured everything down, no more problem.

 

It is helpful to know year, model and which engine. Number of miles.

Basics first! Vacuum leaks/False air leaks in the intake tract.

Pull spark plugs.... One or more read lean or very rich? Checking fuel trims is a good suggestion but where an injector is dumping excessive fuel it will lean multiple cylinders trying to find the right mixture.

O2 sensors are old enough to be suspect as are coils, spark plugs.

Also important to know the engine is healthy and happy. How is compression?