My 74 4.2 Daimler has been off the road for the last 5 or 6 years, I’ve regularly started it, and odd run around the block, recently been getting it back on the road, sorted brakes, clutch etc. Still has the normal oil leaks, rocker cover gaskets and cylinder head oil lines at the back of the head, Trouble is it has just lost oil pressure, had a oil change a couple of weeks ago, always had reasonable oil pressure 40. Now it slowly disappears to nearly zero, comes up a bit then drops off again? Any thoughts as to why?

 

Have you checked the pressure sensor? Or install a pressure check gauge in the block? My XJ40 does the same thing, there will be days it stays up near the middle, other days when it drops to nothing at idle, just haven't replaced the oil pressure sensor with the superseded one yet.

 

Firstly welcome to the Forum.

When time permits please do an Intro in the New Members Area.

As said, a master mechanical gauge is the only way to verify anything.

The Smiths sender for the gauge was a hissy thing from the very start.

 

I borrowed a old mechanical gauge and had enough fittings to put in onto the oil filter housing from where the electronic one was fitted, worked a treat, as I was cranking it over, oil pressure immediately climbed, its at 50 running,and I'm happy with that, I may get a oil gauge and tee and fit it under the bonnet and replace the sender unit, sound like a common fault, thanks guys

 

Perfect !!!


The original Jaguar sensors are a bit shacky. Been there, a NOS unit via David Boger fixed it. Probably will now out last me!!


Carl