oil level sending unit

[g sturgill]

When I purchased my old 73 911 a couple of years ago and finally got it running, (almost a couple of years later), the oil level gauge stayed in the red. The oil level when the engine is warm is fine, and the oil pressure is about where it should be. I've disconnected the gauge to avoid having to watch the needle barely move.

Like most of us, I would like everything to work when and where it should, so I put it on my to do list. checked the wiring, and thought I found a bad ground on the sending unit side, cleaned and tightened it up, but there seems to be a problem elsewhere.

Is it fairly common for the sending unit to go bad? My fuel gauge unit had to be replaced because of corrosion, but oil sending units?

Thanks for any input, gary

[Quicksilver]

I've had 2 of them fail. It seems (from my very small sample group) that the replacements are rather cheesily made.

[JJ 911SC]

Gary

Try a search on "oil level sender" and you will get a few post that take you the removal, cleaning and re-install process step by step.

[FPB111]

Could be "normal" for cold oil that is slow to make it back to the scavage pump. What level shows on the dip stick when cold and the gauge shows in the red red?

[tholman]

my oil level guage always reads quite a bit lower until engine is completely warmed up, then reads correct

[JJ 911SC]

Originally Posted by tholman

my oil level guage always reads quite a bit lower until engine is completely warmed up, then reads correct

That is normal.

If correct, the guage should in sync with your dipstick when you do your oil check at Operating Temperature, on a Flat Surface after Idling for a Minute.

[g sturgill]

I haven't yet let the engine warm up after my faulty ground repair. I'll re-attach the gauge and see what happens after a few miles.

Thanks for the heads up, g

[Determined]

I had a ground problem that caused several issues ncluding similiar to this issue. Once I fixed my grounds everything behaved well.

[Mitch Leland]

Originally Posted by g sturgill

I haven't yet let the engine warm up after my faulty ground repair. I'll re-attach the gauge and see what happens after a few miles.

Thanks for the heads up, g

You really need to have your engine temps get warm before you get an accurate read on the oil level gauge. If it's a cold day then the reading will be lower since your oil temp is going to be lower. If it's a really hot day the oil expands and the level will read higher. That is why you don't want to overfill your sump. But over all my gauge is dead on with the dip stick...

[Porboynz]

When you remove the oil level sense wire the guage will peg itself on full, so if yours is not budging off the low stop then it suggests a hard earth on the sense wire. Try pulling the sense wire off the rear of the guage then measure to earth. Maybe you can hook the float with some wire and move it from empty to full and observe the resistance.

[DRACO A5OG]

Here you go: Oil Level Sending Unit: How to Service / Repair / Maintain