I've been noticing infrequent oil spots on my driveway but wasn't able to place it to a particular car until last night when I noticed a more substantial set of drips from the jaguar. Pics attached.

Questions for the group:

1. is this definitely a rear main oil leak or could it be something else?

2. I read about how the X308s have a oil galley plug near the main seal that can work itself loose and cause the same symptoms, does anyone know if this element of the design was carried into the X350 (I would presume given the overall motor similarities)?

Leaks from the bottom but also there is some seepage from the side (around 5 o'clock from the O2 sensor in the second picture).

 

If you remove the rubber plug (in 1st pic) you will see how much oil is in the bell housing. If there is lots of oil spread around in there it is likely the rear main. It could also be the transmission oil pump O ring but you can tell whether or not it is transmission fluid or engine oil. Oh yes nothing is 100%!

 

Thanks, I've determined it's engine oil.

 

Look higher up. It could very well be one of the oil pan gaskets or a valve cover gasket. Rear main seal failures on these cars seem to be rare.

 

Thanks, I'll check the other gaskets but I replaced the valve cover gaskets under 2,000 miles ago when I replaced the head gaskets. Basically every external seal of the engine has been replaced in the last 18 months except the rear main seal.

 

My 4.2 l S-Type and one of my Vanden Plas 4.2l engines had rear main seal leakage with mileages of 75-100k miles.

 

I guess it varies. Mine rear main seal was dead dry when inspected during transmission rebuild at 125k miles

 

Follow up... I started to have trans-related issues as well so the car is with a performance transmission shop. The diagnosis is: valve body solenoids are worn out, transmission itself is mechanically in good shape, and they confirmed the rear main seal is leaking. While in there I'm having them rebuild the torque converter for good measure, and we might tune the stall speed. Can't wait to get it back...

 

How many miles on the car?

 

145,000, and with this repair I hope to be "done", with basically most of the car serviced or replaced: head gaskets, timing guides, supercharger snout, radiator, every control arm and all suspension bushings save the rear sway bar bushiness and the LSD installed. Of course... "done" is, at best, a transitory state I'm curious to see what the new torque converter does to the car. With my '02 WRX the torque converter alone took 1 second off the quarter mile times, but I don't expect results that dramatic.

 

it’s never the rear main it’s always the little gallery plug

 

Thanks, Xalty, do folks just tighten this back down, or clean and apply some gray RTV to the plug first?

 

I would opt for the latter but use locktite thread sealer.

 

Quick update, trans was pulled on Monday and now have the full diagnosis. Multiple parts of the torque converter were worn, including the sprag and lockup clutch. The solenoids are all being replaced, and the transmission clutch packs had 30% life left. It's all being rebuilt and should be able to tolerate more power than I'll put through it; I should get the car back mid-next week.

The rear main seal was the culprit, but for good measure they redid the galley plug too.

To recap, the symptoms that caused me to send the car out for transmission repair was: 1. loss of acceleration at highway speeds while making full boost with no CELs, 2. brake stall speed seemed abnormally low at 1,000 RPM with an unusual 'whoosing' noise; and 3. some 'clacking' noises under acceleration as well (but not knock).

 

Were you leaking engine oil or transmission fluid? My car is leaking transmission fluid at exactly the same area as in the first picture. My fluid is certainly clearer in color.

 

In my case it was engine oil, the rear main seal had failed.

 

If you don't mind me asking. Who did you have replace your rear main seal? I'm also in Mass and mine just blew out...

 

When my main seal started leaking, I also started to experience some symptoms that I felt were transmission related and so I decided to have Level 10 (performance transmission shop in New Jersey) rebuild the transmission and redo the rear main crank seal when they had the transmission out. Turns out that my transmission was not the issue, though the clutchpacks were at about 30% of life remaining (issue turned out to be a clogged cat but that's another story).

With respect to shops in MA, I would focus on transmission specialty shops. The auto repair shops I called seemed to immediately get scared when I said "Jaguar", and the independent Jaguar shops would of course take the work but at that time they were all booked up for weeks. My recommendation would be to find a transmission specialist who is familiar with ZF transmissions -- while they don't need to do any work on the transmission, step 1 on the rear main crank job is "remove transmission". Good luck with it!