Hi All,

Ever since I purchased my XJ in October, I have noticed a slight vibration being translated to the occupant compartment. Most noticeably when at a stop light. As soon as I lift off the brake and start to accelerate it seems buttery smooth again. Is there a way to know which mount (or if anything else should be looked at) is starting to go on my X358?

Thanks for your help!

 

Trans mount is more suspect than the engine mounts and easier to tackle.

 

I have replaced all 3 (2 engine, 1 trans) mounts on my vehicle over the years. Telltale sign is the hydraulic oil in the mount having leaked out. Will look like very dark red oil. In one case I had found a puddle of what I thought was power steering fluid on the belly pan. And I could see the oil on the trans mount had leaked all over the crossmember.

If you don't have any evidence of that, you can have someone help brake torque the engine in D and R and watch the motor mounts to see if one or both has excessive movement.

 

I finally got around to replacing both my engine mounts and transmission mount. The slight vibration is still slightly present. Anything else I could try?

 

check plug condition/gap, and smoke check for vacuum leaks

 

Check for vacuum leaks.

 

Thanks! Are there common areas for vacuum leaks on the 350/358?

 

The vacuum lines. Run a fuel trim.

 

The supercharged cars are harder on the mounts. I have replaced one engine and the transmission mounts.

 

I plan to start with replacing my spark plugs in the near future, instead of just checking gap. Should I replace my coils or reuse my current ones?

 

Whining broken Alternator in addition to the 2 oem engine mounts and oem engine transmission mounts will be changed very soon on my 2003 xj8 with 341000km .
only have a slight wiggle when I start the engine cold thats gone after a couple of seconds.
Pan, filter, oil ,sleeves, have been changed recently with zf kit
hope for some improvement