Hello, this is my first time ever on a forum so please bear with me. I am also brand new to the Jaguar experience. I got XJ8 from the auction with 79000mi on it. Overall condition is great ? but I have been monitoring a strange vibration pretty much since I acquired the vehicle. Under light exceleration at 1500-1700 rpm I am hearing and feeling a fairly low pitch humming. Seems to be coming from mid to front of vehicle. Very consistent and easily reproduced.
XK has TSB for that issue (solution is to put new brackets around the CAT)
I put the car on the ramps but didn't mention any issues
Any thoughts?

 

Any codes ?

 

Do you get the humming/vibration at 1500-1700 rpm when revving the engine to this speed with the car in neutral and stationary?

You said you get the vibration under light acceleration when you reach 1500-1700 rpm. Is the vibration still present if you stop accelerating when the vibration appears and continue cruising at that particular speed that you have reached?

Does the vibration disappear when you drive at speeds above 1700 rpm?

To diagnose whether your vibration is actually driveline (and not engine) speed related, drive the car until you reach the speed where the vibration appears. Note the car speed. Then increase the speed say 5-10 km above the "vibration speed", put the transmission to neutral and observe whether the vibration is still there. If it is, and if you don't have vibration when revving the engine in neutral and car stationary, then you should inspect the propshaft couplings (rubber "doughnuts") at front and back as well as the rubber mounting of the propshaft's centre bearing.

 

P1000 is pending - thats it.
M. Stojanovic , I can feel vibration ( passenger as well) only between 1200-1700rpm. it doesn't matter what gear, RPM only related/ Vibration is gone in asa I release the pedal and iI can feel it only if engine is under load - car is accelerating. Feels like exhaust is touching the bode - i need to check the car on the lift with running engine

 

Your issue is much clearer now. As you inspect things, check the condition of the engine mountings as well as the transmission mount.

 

I agree, under load, likely engine and trans mounts. Had the same issue.

My trans mount was completely sheared and the motor mounts were toast.

 

ok, ill check it on the weekend.
Are engine mounts oil filled? Are there good aftermarket parts or its bettet stick with OEM?
There is only 79000 in the Jag

 

Here are mine at 70,000 miles and 17 years old (age is often a greater cause than miles)

Engine mounts are oil filled.

UROs are $75.00, OEMs are $185.00, but I would recommend you spend the money and go with the OEM Jaguars.

They are a bit of a pain to replace.

.