Hi Everyone,
According to my jag manual, all 3.6 engines were specifiedwith an oil cooler. If the cooler is removed, the “adapter block” that fitsbetween the oil filter base plate and the cylinder block (and from which theoil cooler feed / return pipes flow) should also be removed. The filter baseplate is then bolted directly to the block.
My 1990, 3.6 manual does not have an oil cooler but stillhas the “adapter block” between the filter base and the block. The base of the“adapter block” (where the oil cooler inlet / outlet pipes would normally runfrom) has an aluminium, “U” shaped connector linking the inlet / outlet ports.It looks to me that the car left the factory like this i.e., no oil cooler wasever fitted. Car runs ok, pressure good and does not overheat but is it thenorm for UK spec cars not to have an oil cooler?
The reason I have been poking around down there is that Ihave an oil leak from either the oil filter base / adaptor block / U connectoror maybe the base of the adjacent oil filler pipe where it bolts into theblock. It is difficult to see where the leak originates from so would be keento hear if anyone else has sorted oil leaks in this area and what they found.
Thanks for reading and sorry for the ramble.
LeeP

 

There are 4 o-rings at the U connector. They turn hard with time and causes leakage. Been there, done that with my XJ40.

 

Thanks Leo, that is really useful. I cannot find the O-rings listed anywhere. Do you know the part number or even just where you obtained them?
LeeP

 

You're welcome. The U connector and o-rings is shown here as pos 7 on the XJ40 spares site. CAC5118

https://www.jaguarclassicparts.com/u...-3-2-4-0-litre

 

Thanks Leo, I have the O-rings now. Do you know if it is possible to replace the O-rings with the oil filter head still in place on the block? I thought I might be able to do it by removing the nut from underneath the connector housing or does the whole assembly have to come out and be done on the workbench?


LeeP

 

You can remove the U connector without disassembling anything else.

It is hold in place by one single stud with a nut mounted from below. You will need a 12 or 13 mm spanner. I did it from above, but it may be easier from below. I'm not sure if the front beam will obstruct access.

It's not easy, but it's possible, at least on an XJ40

 

Thanks again and I hope you get your starter motor sorted. Sorry I haven't any suggestions to help as electrics baffle me.
LeeP

 

Feedback:
Completed the job today so some feedback in case anyone elsehas to do.
Firstly, I got a lot of guidance from our friends in thexj40 forum. Thanks chaps, especially Leo in Denmark. I had forgotten the mechanicalsimilarities with our own cars so worth a look at the xj40 forum if you want towiden searches. The link below shows how to replace the seals on the oil coolerbypass for an xj40:
https://www.jaguarforums.com/forum/xj40-xj81-25/oil-pressure-sender-133621/page2/#post1332052
Regarding replacing the seals on the XJ-S oil cooler bypass:

• I managed the job from working above – didn’teven have to remove the oil filter.
• You need a ¼” drive, 13mm deep socket wrench(not enough room for ½”” drive) and have to work by feel.
• I had to use a deep ring spanner just to breakthe seal on the fixing nut but there is very little space and a deep socket is amuch better fit if you can get enough torque on it.
• There are 4 O-rings to replace that cost about£1 each – I got mine from Britishparts who delivered very quickly but there areprobably others out there
• It is an hour’s work if you are determined anddon’t have to pause to think, plan, make coffee or go and buy new spanners

After a 10 mile drive today everything seems wonderfully oiltight – fingers crossed.
Cheers,
LeeP