Low oil pressure shutdown...NOT !
 

In doing my due dilligence for the 'Real Gauge' project (see https://www.jaguarforums.com/forum/x...e-gauge-62813/), I set out to find out if the low oil pressure switch actually shuts down the engine. I cannot recall where, but I believe it had been posted somewhere that it does.

Well, at least on my 2001 XKR it does not. When I simulated a low pressure fault, the engine kept running, just the low oil light came on and a low pressure warning message appeared. I could even start the car with the low oil pressure warning.

All the more reason that I will add an audible alarm to the JagWrangler 'real gauge' conversion mod.

I'm greatly looking forward to your product release.

And I agree...I can't remember anyone documenting an actual low pressure shutdown. But I've heard several stories that illustrate the opposite.

You might remember BriteRedXKR (I think that's the name), from earlier this summer...she banged up her oil pan badly enough to cause a major leak. The engine emptied itself before she got home, didn't shut down, and that was it...a permanently dead engine.

It is also a wives tale in C4 Corvettes also.

The only cars I can recall having a low oil pressure shut-down circuit had the aluminum Vega engine - Vega, Astra, Monza, etc. Ironic, those were the engines you wanted to see blow up. Then again, there's a lot of things I havent seen or can't recall...

Well there is a low oil pressure shutdown. It's just that it is rather permanent and requires a new engine to reset it :)

On a more serious note, being able to start with zero oil pressure is not surprising because oil pressure won't really build until the engine has started. Otherwise, you would need to tie into the crank signal at the ECM and have an override push button just to get the car started. Automatic shutdown might also be undesirable from a personal safety standpoint in the middle lanes of an interstate. Good for the engine, not so good for the occupants. Sooo ... no manufacturer is going to put it in as a standard feature.

If I recall correctly the Vega used voltage from the alternator to determine engine operation and the oil pressure switch inhibited the electric fuel pump.

Better to have oil pressure switch to kill the engine vs. lack of lubrication killing it. Either way, the engine is going to stop.