Removal of stuck, or tight, leaking Oil Pressure sendor on V12

I agree that there should be concern about damaging the Oil Feed Pipe (EAC3489) or Adaptor (C4202) for the Oil Gage Transmitter if too much force is applied. As you will seen in the attached picture they are not very sturdy parts and I suspect that many have been broken over the years upon removal.


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Nice pic!

And this photo also illustrates one distinction between the H.E. and the pre-H.E. This is an H.E., which you can tell because the spark plugs lean toward the centerline of the engine. On the pre-H.E., the spark plugs point straight up. And the difference that makes in the difficulty of changing plugs has been the bane of many an H.E. owner.

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That is indeed a great picture. Also shows the copper washer

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PB Blaster is good at dissolving rust, sometimes.
I keep two other rust dissolving products just in case one or two don’t do the trick.
One is Mouse Milk, popular with aircraft mechanics, I have been using it for years.
The other is Kroil, they sent me a sample can of it years ago and I just started using it.
It worked so well I bought a few more cans of it.
However, none of them will work against a pipe thread with pluming dope on it.
The only solution is heat and force.

I remember Kroil . NOT cheap, but they do guarantee that if it doesn’t loosen whatever you use it on they will refund your $ (or was it 2x that amount?). :open_mouth: Seems like of late I don’t see it around as much, though … :confused:

They are still around.
I don’t remember what I paid, but I bought four pint cans.
Since I retired I can’t throw around money like I used to.
I’m avoiding aerosols, too much waste.

Hello Greg, and others - so how did you get the spray nozzle tube, of the PB Blaster, close enough to the OP unit fitting to spray it - I have tried all different ways but just can’t seem to get the spray to actually get to the connecting joint - used a mirror but just kept spraying below the junction - any thoughts of how you did it?

Even with that long red nozzle attachment? I find that hard to imagine.

Hello Greg - the fixed nozzle on my can is approx. 7 inches long - it is connected to a swivel top that is a shutoff button type - the other cans have the 6 inch free plastic red tube that you put in to the spray nozzle when ready to use for a stream - I tried going in sideways, upside down, from left side, from right side, from space by throttle stand (I have not removed the throttle stand, just the throttle capstain on top) - did you remove the whole throttle stand?

Yes, i removed entire throttle pedestal, for sure! Only 15 minutes. I found a long 1/4" extension with swivel socket worked fine on difficult back bolts.

Hello Greg - okay I guess that is my next step - guess this will gain more room for turning the socket driver with the crows foot also - had thought about removing the stand base, but thought maybe it was just extra not necessary work - will post results of next attempted steps - thanks, Tex.

It will be miles easier, and it will be helpful to get your hand in there.

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The funny part of all of this work, is, when I changed the oil pressure switch sensor, for the instrument panel light, on a fellow’s 1990 XJS V12 convertible, approximately 15 years ago, I just reached in with the correct spanner and removed, and installed, the unit, without removing anything else - he had an oil leak and was told that was the culprit by someone else, who did not want to attempt to change the part - and yes, it did take care of his oil leak problem - I did pull back the oil pressure sendor rubber cap and verified that the unit was not failed and leaking, like mine is, but again, he had a good oil pressure reading at the gauge, so I did not expect to find any leak problem at that unit - even though I am not as agile as I was then, I did not figure I would have all this trouble changing my units - thanks, Tex.

Only thing easy to change on this car are the front shocks and windshield wiper blades!

If you remove the throttle pedestal you should consider having it modified like I and some others have done to make it easier to access the two rear bolts. Unmodified and modified pedestals are shown in the attached pictures. I did not come up with this idea but I share these pictures from time to time when pedestal removal is discussed.

I had difficulties accessing the two rear pedestal bolts in both of our V12 Jaguars and had a local hot rod machine shop make the modifications to their pedestals when I removed them for other work. Now removing the pedestal is a “walk in the park”. Some folks like Greg have not encountered difficulties with the rear pedestal bolts. I did have challenges each time and decided to get the pedestals modified to make future removal and replacement easier and quicker. I have been very pleased with this modification that I first learned about here on Jag-Lovers.


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I have used Kroil many times to loosen up frozen nuts and bolts and found it to be an amazing product. I apply Kroil to frozen/rusted fasteners, let them sit overnight, and often the fasteners easily come apart without breaking the next day. I purchased Kroil online on eBay as I haven’t been able to find it in any stores. It is a lot more expensive than other products so I usually use Kroil when other products fail to get the job done.


Yes, I found using a 1/4" drive ratchet, 1/4" drive long extension, u-joint swivel, and final socket worked very easily to remove those rear bolts.

To reinstall them, I simply put a bit of masking tape on the bolt head so it sticks in the socket, and with the right finesse I can hand start them using the 1/4" drive long extension. After tightening them down, I just use long needle nose pliers to remove masking tape.

Yes … I remember reading on their ads (and cans) how their product works (and supposedly in a unique way to other “lubes”). The molecules of the Kroil substance are supposedly so small that they are able to slip into tiny crevices, cracks, etc. that competing products cannot and, IIRC even slip between molecules of the frozen object. In fact, I think they were talking nano-somethings of “smallness” being involved :open_mouth::man_scientist:

Hello Paul Novak - Is the Kroil, that is sold at Home Depot here the USA, the penetrant that you are suggesting using for soaking overnight to release nuts - thanks, Tex.

Paul #1 here … :grinning_face_with_smiling_eyes: IIRC, Lowe’s was about the only place I was ever able to find the product in the stores after I bought mine (online?), although I think WM did carry it at one time, for a short period. It was probably too $$ for their customers, so it was dropped from their inventory. :thinking: