It's always the little details isn't it

If an adjustable switch is fitted, I'd suggest adjusting it so that it comes on when pressure falls below something like 10-20 psi or so. Oil pressure idiot lights are usually designed to come on when oil pressure is, like, 4 psi or 0 psi or something. At this pressure, it's actually a "Your engine has just been destroyed" light.

Unless you're driving my Datsun pickup. I add oil when the oil pressure gauge starts falling to zero.

Hmmm. Now I wonder why I've never seen that light turn on on my car at all. Guess I've got more than a missing oil temp sensor.

How does the oil pressure light work? Is it tied to the oil pressure sender? My pressure gauge works, but I have never seen a warning light come on, even at idle or while starting.

The oil pressure idiot light sending unit (switch) is a different critter. Mine is located on the oval plate at the rear center of the engine near the firewall. It's about as big around as a nickel.

That's exactly what I was looking for. Got close last night, but never stumbled upon the right numbers.

Now to find someone who sells GROTE, in particular these parts. Seems very few places sell GROTE.

Big REd Light
 

Here is one I did with parts from Autozone.

http://forums.pelicanparts.com/uploa...1068499859.jpg

http://forums.pelicanparts.com/uploa...1068499632.jpg


Mine comes on at 15lbs..... Works great. I actually had a oil line come off at an event. the light came on right away. Shut motor off, no harm no foul, no problem. Motor was fine.

I've used these guys for lights: http://www.thelighthouseinc.com/asp/default.asp
Also, these guys have some great deals on LED lights for trucks, and many are the same sizes: http://www.partssystems.com/home.html

Tom

That light looks like something out of a Mel Brooks movie!

Any NAPA or Big Truck supply will have that lens and rubber grommet. They are standard size used on commercial trucks and all brands are interchangable.

Mark,
What do you have to do to "set" the particular pressure to trigger the light?

The dual pole sending unit (one pole for Oil pressure and a pole for oil light) that I bought had the option of different activation pressures. Screw it in, attach the leads, and bingo. It is set.

I think this is a standard part you can order from most high performance parts stores.

Mark,

There is a Porsche part oil pressure switch that has a 917.xxx.xxx.xx part number that was used on 935s and many others. It switches at about 45 psi and is adjustable over a fairly wide range of pressure. I keep mine at about 40 psi. When the engine is hot and only below about 4500 RPM does the light come on. I use a large trailer tail light above the dash.
Believe it or not, I can turn the light on under extreme braking at 8000+ RPM.

There is another important switch.
I didn’t use an alternator, just a shaft in place of the alternator. That meant there was no indication if the fan belt was not working. Porsche has a little air pressure switch with part number 908.xxx.xxx.xx that can run another warning light.

I’ll see if I can find you the part numbers. They are regular Porsche racing parts, no mistery.

Best,
Grady

Do you have your oil tank modified? A baffle will help this dangerous situation.

Tristan

Tristan,

Yes, extensively on 911s and 914-6s. When I raced a 935K3 I could turn the light on in certain circumstances of breaking regardless of how much oil was in the tank.

I think this is the reason why the GT3-RSR (and earlier) has the relocated oil sump tank in place of the engine cooler.

Best,
Grady

The pressure circuit to the bearings comes from the tank. Oil drawn from the sump just goes back to the tank.