Help Diagnosing 95 XJR Motor Problems

(Mike Baker) #1

New member asking for help diagnosing my motor problems. Service history - previous owner took it to Jag dealer in Naples, FL in 2012 and spent $7K+ to repair? and then parked it? Jag dealer will not share service report? I bought this 95 XJR with 50K miles from an estate where it had been sitting for 5+ years. Son of owner had no useful knowledge of its problems, just wanted it out of his driveway. No oil leaks on driveway under car after years of sitting. . Towed it to my mechanic and he replaced and/or rebuilt the whole fuel system to get it running - bad gasoline. Then discovered cylinders 5 and 6 not firing and using lots of oil = 3 qt in 15 miles but not smoking from tailpipes? Towed it to a top foreign car specialty shop for further diagnosis. Compression test, leak down test and air pressure into cylinders 5 & 6 revealed at least a burnt exhaust valve in cylinder 6. Chose not to repair there due to $5K+ estimate. Drove it home 15 miles starting with full oil and low oil pressure showed up 1 mile from home at low rpm and the motor needed 3 qts oil to get in the safe zone on dip stick - did not see any oil smoke trail. Mechanics keep replacing fouled plugs? Now, suspecting blown head gasket, I flushed coolant system and found no oil. Starts right up and runs rough with max rpm of 2K. That is what I know at this point and am thinking cylinder head rebuild but what about the outrageous oil loss??

(Mike Baker) #2

Ran out of post space? Cylinder head rebuilders think oil usage is worn out head - valve guides, etc. or worn out oil rings? Has anyone had similar experience with their X300 motor? Any thoughts on further diagnosis steps before tearing the head off?

Thanks in advance for any help!


(j limongelli) #3

Mike, its all about the vin number…OR do you have a GLOVE BOX on the passenger side.
Sounds crazy but early cars did not have a glove box and those cars had lumpy cams and loaded up with hard idles.
These cars are 20 years old so it can be many things…
If its bone dry and no rust. keep it.
Ethanol gas and submerged pumps are a killer.
Theres too much to list, post some pictures.
Head gaskets were an issue with the early chargers as well.
Good luck and report back.