Low oil pressure cutoff switch

[SourceLee]

Here's a laundry list of questions. What are your thoughts on a low oil pressure cutoff switch. Donor engine is a 1992 302. I noticed a bad oil leak not too long ago at the remote oil filter fixture. Nothing catastrophic but a good amount of oil leaked out while driving. If the engine ran out of oil and lost oil pressure it could've wrecked a perfectly good engine. Would it be smart to install a low oil pressure cutoff switch inline with the fuel pump relay (control side)? I see at least two problems though. Killing the engine while driving may be dangerous. However what's the difference if the switch kills the engine or the engine kills itself! The other issue is the ECU wouldn't be able to prime the engine during a startup. Is it really necessary to prime the engine before startup? I owned a 1986 Camaro with a TPI fuel injection years ago. That particular EFI system used a low oil pressure cutoff switch inline with the fuel pump power. Therefore I don't think the fuel pump would prime the engine before startup. From what I remember the Camaro started up fine. Plus GM didn't have a mass recall on stalling cars while driving. You may be thinking, why not an idiot light? Sure, however it would require me to notice the idiot light before it's too late. Maybe have the cutoff switch kill power to the ignition coil??? Chime in.....

[Dave Tabor]

You may be thinking, why not an idiot light? Sure, however it would require me to notice the idiot light before it's too late. Maybe have the cutoff switch kill power to the ignition coil??? Chime in.....

This works well for me:

https://www.amazon.com/gp/product/B000FOUNYE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Dave
Gen III Coupe #17
13,000 miles

[AC Bill]

I am in the habit of checking my gauges constantly so never felt the need for a switch. I suppose though, even a few minutes of inattention and a sudden dump of oil could be a disaster. I don't have a remote oil filter on my 302 as I never thought them as necessary, being the stock oil filter position is easily accessible. To get a sudden dump of oil, I'd pretty well have to tear a hole in the pan.

Not sure what you mean by priming the engine before start up. Do you mean the fuel pump kicking in initially upon turning the key, or oil priming prior to start up?

[CraigS]

- I would not connect it in any way that would kill the engine. To me that would be a huge safety concern. My experience w/ cars that fire up the fuel pump briefly prior to or while starting, the purpose is quicker engine starts. They usually also have some code that would shut off the fuel pump if it doesn't see any crank speed. Think accident where the engine stopped but the key is still on, they want to shut down the pump in case there is fuel leaking somewhere to reduce possible fire.
- I would bet that your Camaro did in fact have a bypass to run the pump prior to seeing oil pressure.
- Priming the engine to me means firing up the fuel pump. Whether it is needed or not depends mostly on how long the car has sat since it was last started. After engine shut off the fuel pressure in the system will bleed down eventually. It will generally take several hours, so sitting over night you would have near zero pressure. Unless there is a leak somewhere though, the bleed down stops as soon as the pressure gets to zero. So there may be zero pressure but the system is still full of gas. In this case the pressure builds very quickly, as in a second or two. Running the pump before starting I think was simply so the engine would start a little faster and the owner would be happy. Now a days, I would bet they are more worried about emissions. If fuel pressure is low the engine will be lean and could cause misfires for a few seconds which would ad to the overall emissions.
- If you are concerned, you could install a light like Dave did. Make it a really bright one so you will see it in daylight and put it centered above the steering wheel.