A-Z

Where is our oil temp measured -- before or after the cooler?

thx, Andy

songman3

It's measured by temperature sensor set into the bottom of the oil tank

The oil is drawn from the base of the tank into the supply side of the primary pump.
- from the pump it flows through the lower engine block gallery.
- from there it passes through the oil filter.
- from the oil filter it then passes through the external oil cooler.
- from the oil cooler it runs to the upper main galleries whence some is fed to the crankshaft bearings and some lubricates cam bearings,valve lifters.
- from the lifters, oil passes up through the pushrods to lubricate the top end - rockers, valve stems,etc.
- the oil then drains down into the sump and is scavenged by the secondary pump and fed back into the oil tank.

Unreal

So basically it would be before and after the cooler. It is in the tank.

A-Z

thanks!

Mark2009

Before the cooler, in practical terms.

Very timely thread, I just had someone ask me today where the oil temp was measured and I had a brain fart and thought of the oil pressure sensor location instead (back of the block, after the cooler). So I said after the cooler. Later I realized I wasn't sure. Now my memory has been jogged

The guy that asked me said that the after-the-cooler temp was the important one to monitor. Oh well.

Mark2009

Had a brainstorm the other day (ruh roh!) . . . if you want the after-the-cooler oil temp, tee into the oil pressure sender at the rear of the intake manifold. I do believe that if you used a GM sender you could switch it into the wires for the existing oil temp sender and read either or on the DIC, dash gauge, and HUD (switch it back and and forth, or hook the computer up to the new oil temp sensor only).

Food for thought....

Undy

Don't think that'll work Mark.

Oil temp requires a certain amount flow across the sensor to give a correct temp, oil pressure doesn't. The OP sending unit is in a stagnant spot in the oil system. You more than likely would read engine temp.

Mark2009

Yeah... I was thinking that the oil, though stagnant, would conduct its temperature up to the oil pressure location but I just checked the thermal conductivity of oil and it really, really sucks compared to aluminum (block). So you'd probably wind up with block temperature

Oh well... one brainstorm down, 999,999 to go

There does appear to be an oil galley block plug just above and behind the oil filter, but it may not be accessible with the engine in the car. I believe this would be just after the cooler.

Undy

I'd probably modify the return line from the oil cooler to accept an oem oil temp sending unit. I'd then put a small toggle A-B switch somewhere hidden from view on the console. Better than that one could incorporate a mild-to-wild remote unit controlling a NO/NC relay.

Many ways to accomplish...