BimmerJeeper

While driving, there is a mild grinding/squeak sound.
Feels like it's under the driver's seat.
I sort of thought it might be the driveshaft?

When I pulled to a stop and turned the car off,
there was a brief "Harley bike" sound that came from behind the driver's dash / cowl area.

Did some reading.
drive shaft carrier bearing?

Let me drive again and better try to explain the symptoms.
Driving, idle, etc.

BimmerJeeper

It sounds like something is clunking under the car.
Sort of like when a roller coaster pulls you up the big hill.

There is a audible rumble shudder when I turn the car off.

I think I can hear it when the car is in neutral / park.

Any ideas?

jordan96xj

Check the condition of your motor mounts and transmission mount. In particular, some of your symptoms sound like the transmission mount is in bad shape and allowing the exhaust to contact the crossmember that runs right under the driver seat.

BimmerJeeper

I will look into how to inspect the trans and motor mounts.

PatHenry

If you take a pry bar or long screwdriver and pry between the transmission and cross-member you should not be able to move the transmission. If you can then the transmission mount is bad.

It's not a difficult replacement if you have a good floor jack. If you do replace the mount, look for a mopar or a napa brand part. Do not ever use the Anchor brand - it's worse out of the box than a worn OEM part.

jordan96xj

Thanks to the Anchor brand, I can change my transmission mount in 14 minutes start to finish.

By the time I took the original worn mount out, put the Anchor garbage mount in, then took the Anchor mount out to rig it with some additional rubber support, then put it back in, then take it out again, and finally install an OEM mount (all in the period of about 1 week). I got pretty proficient at the job. I think I'm gonna open a shop called "XJ Transmission Mounts : While You Wait".

BimmerJeeper

The sound is coming from the engine area.
It is most pronounced when starting and stopping the engine
And at low speeds (unless I just can't hear it while moving faster)

I have an appointment with the local mechanic in the morning.

Engine mounts look pretty buried in there, and rusty,
so I will just let the pro handle this one, if that is the issue.

I definitely have lost interest in trying to DIY the XJ.
This tells me it's time to start shopping.

Sota

BimmerJeeper

Might be an exhaust issue.
Mechanic identified it within seconds of driving the car.
Hanger rod is cracked, and exhaust is resting on the trans cross member.,

BimmerJeeper

That was just a temporary repair.

A few days later, the tailpipe separated from the muffler,
so I had the mechanic replace everything after the downpipe.
Cat, muffler, tailpipe, etc.

Problem solved.

PatHenry

Nice!! Glad to hear it Bimmer!

So the barnacle lives on.