Hi there, new member here. I have a late series 2 XJS v12 (first registered early 1991) in the UK (no mooses/meese here!)
I have the same moaning noise which has actually got worse, but it is exactly as others have described, coming from the front but more apparent from inside the cabin. I too have thought either fluid flow or vacuum - it did for a while seem to go away with higher engine revs, now it is all the time and loud enough to be really annoying.
My car is a low mileage (40,000 miles) which did very little in the last 20 years as it was in storage with an engine fault. I’ve had a complete engine rebuild done (via specialist garage) and a lot of other work done in the process of recommissioning the car. Having sat so long many ancillaries are likely to play up so I expect to do more work, identifying other issues as they appear.
Given the complete engine rebuild with all new parts I suspect it is not in the engine itself but rather an ancillary item. Certainly vacuum leakage is high on my list of suspects. But it could be the trans which has been showing signs of a valve body problem.
If I get to the bottom of it I’ll report back, in the meantime I hope someone else manages to solve it.
If i remember next time i put my car on jackstands, ill listen with stethoscope at oil filter housing. Based on TSB and where i think noise is coming from, i still believe it is oil pressure relief valve.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
83
What makes it go away? When the oil temp rises a bit?
Hard to tell. Takes 20 seconds to 1 minute to gradually disappear. The noise is less when revving rpm or when dropping rpm by shifting into D. But still there.
Most pronounced in P or N at 1000rpm when cold.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
86
That oil pressure relief valve has that infamous question-mark-shaped tube to direct the relief into the sump. So, take the tube out and replace it with a 5-foot length of hose looping up to the top of the engine compartment. While the thing is calling moose, clamp that hose and see if the sound changes.
Brave “Running Board” - reminds me of how my tech bud acted (before I gave him the boot a few weeks ago) whenever I asked him something about how his work was going on Superblack, just in slower motion :
I always wondered who made the “Jaguar” brand filters, as I suspect they’re not made by Jag themselves, but subbed out to some other co. that makes filters.
To Jag specification so there may be a difference in an actual wix filter and a wix manufactured Jag filter if they do in fact make Jag filters wouldn’t you think
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