My oil light comes on at idle when hot, like 210+ degrees. I only see it get that hot on 100+ days here in AZ, but it is happening. I was running SAE30 oil and I changed to 20/50. It still happens, so I figure I can bandaid it with an oil cooler or a high pressure bypass kit. Anyone else have experience with this?

BTW, my sender is a new VDO dual head unit extended on a piece of steel braided brake hose, gauge is a 911 unit.


Oh and the motor is a basically stock djet 2.0, 73 variety.

How many miles on the motor?

I read in the factory manual where that was noted as being 'normal'

Sounds like you have elevated oil temps that are thinning the oil and dropping the viscosity resulting in kless pressure.. Put some instruments in that car!

Jake has a point, but also the car when in idle running at a low RPM doesn't have a high oil pressure. This is a very normal thing, and especially if you have your idle set very low.

I have 911 gauges in a triple cluster. This happens when the temp gets up over 210, and yes the oil pressure is at the bottom. I don't know the exact value, but I would guess 5-10lbs. Obviously, enough to turn the light on.

I don't know how many miles on the motor. I bought the car from a guy who let it sit for a few years. I pulled the motor, put new seals in the obvious places, and did a bunch of other work to make it dependable again.

And, I've also read that its normal but it doesn't make me feel any better.

And that is how I get the light off is put my foot on the pedal and get the idle up. I think my idle is around 900-1000 right now. I could speed it up a little, but it seems like it is about where it belongs.

Not that it will fix the apparent oil pressure problem, but is your gauge matched to the sender? It DOES matter. You need the correct sender for the actual instrument in your car. The Cap'n

Yeah, that is where it belongs, but that is why they say it is normal. As long as it goes up when you bump your throtle you should be fine. It is hard on an air cooled car in high heat, but it should be fine.

AFAIK its correct. I have a 911 0-150 psi gauge with the VDO 0-150 psi dual head sender(the one with the gauge and oil light). Regardless of the gauge/sender the light still comes on. Look at it this way when the light comes on, the gauge has bottomed out on pressure, and the temp gauge is over 210. Like I said, this only happens after driving for a while in 100+ ambient temps.

If its normal, I'm not going to worry too much. But since I live in a hot climate, should I have an aux. oil cooler anyway?


Also, I still have a rain tray, maybe I should pull it out and see if the car runs cooler?

I would say that taking that off would help a lot. Adding anadditional oil cooler could be a start towards a 6 though

the rain tray removal doesnt help, ive tried it and tested it with a digital CHT. We're talking like 3-4 degrees at most.

So what are your oil temps getting to in 100 degree heat? You say 210 plus, how much plus? How long driving. ect.

I've been sorta doing my own experiments with different cars, gauges and actual oil temps using the dipstick thermometer witch I've checked against a pyrometer, and other gauges to verify accuracy.

My findings are that even stock cars run hotter then most owners think... like 230-240 often, in that kind of heat.

Any way to verify the accuracy of you gauge? Pyrometer ect.

Rain tray removal does help with OIL TEMP.

I added a small 19 row mocal cooler under the rear trunk, and I still saw 240 briefly after 35-40 miles of highway driving in 90degree plus heat, pulling 3800 rpms most of that time. I will be adding a fan very soon, so move more air.
My car is web camed, 2.0 with dual 40's.

My 911 has the same flicker at idle when it get's above 240, it's only been there once (huge backup on highway...) But I've never had the 914 light come on.

Ferg.

I would say just over 210, maybe between 210 and 220 indicated on my gauge. It takes a while to get there. The first time it happened, I was running down the freeway in temps probably in the mid to high 90s. When I got off the freeway the light came on. At that point the motor had reached its max temp and everything was heat soaked. I didn't worry too much because I knew the oil temp was up there. I just held the throttle a little to get the R's up.

After I changed to 20/50 it took maybe 20-30 minutes of driving and one or 2 lengthy stops at various stores, and I was trying to get it hot to see if the light would come on.

I don't know how to verify accuracy except with maybe one of those dipstick units or another gauge. Doesn't Gene Berg swear by those dipsticks?

BTW I don't have a thermostat, but I do have the flapper in the fail-safe position.

mine is the http://www.mainelycustombydesign.com/ one.

I have complete faith in it for these reasons...

1. I've boiled it, cross checked it with a pyrometer, and checked it against other gauges. I would say it's very accurate.

2. It measures very close to where the taco plate and your original sender reads.

3. It's mechanical so voltage ect will not affect it.

Yes, you can't read it from in the car, but I've calibrated my non numbered temp center console gauge against it so I know where I'm at in real time...

Ferg.