Oil Coolers

[FluoFerret]

I would change the sensor against a new one. Usually the oil a lot more time to heat up. My van needs about 15 minutes and 10-15 miles to get the oil above 75°C.

that would be the third sensor I swapped in, and still changing nothing 🙂 the other two checked out to be okay.

 

[pontiacgp]

The oil temperature sensor is located in the engine-block just above the oil filter. That's the place where according to the GM Manual the temp sensor sits.
The wiring should be okay, but this afternoon I will have another look at it, just to be sure.

I have nver seen a SBC with a oil temperature gauge in a car from factory, that is the location for the oil pressure switch/sender. I would put the oil temperature sensor in the pan

 

[FluoFerret]

I have nver seen a SBC with a oil temperature gauge in a car from factory, that is the location for the oil pressure switch/sender. I would put the oil temperature sensor in the pan

Hmm, but that's the spot where everybody told me to install the sender, even some of the literature.

BUT!

I checked the gauges and its sender again. here's what I found: when there is no contact, two identical gauges (engine oil temp and transmission temp) have their needles a bit below 100, as shown on the picture below.


Once I give contact, the transmission temp gauge stays under 100, while the engine temp gauge shoots a little over 100, as shown below:


Interestingly, the engine is just as cold as the transmission and I didn't find any issues on the cables. both gauges share the same (+) and (-). Only the sender-cables differ, so I switched them and I get almost the same result.


The sender-cables look intact to me, so the big question is: what the fluff is going on?

 

[KCP]

Ok, so now it's time to first get the correct numbers. Get a complete oil temp gauge set with corresponding sensor included, i.e. this cheap one and use the sensor as oil drain plug (don't forget to order the right thread adapter for that).
This way you know how hot your oil gets in reality. Then start with re-wiring the old gauge from ground up. Since the sensors act like resistors with changing temps you might have some contact problems between sensor and gauge.

 

[FluoFerret]

Ok, so now it's time to first get the correct numbers. Get a complete oil temp gauge set with corresponding sensor included, i.e. this cheap one and use the sensor as oil drain plug (don't forget to order the right thread adapter for that).
This way you know how hot your oil gets in reality. Then start with re-wiring the old gauge from ground up. Since the sensors act like resistors with changing temps you might have some contact problems between sensor and gauge.

I got myself an infra-red temp-feeler that allowed me to measure the temperature of the oil sump once heated up. it says 105°C. that seems okay. a bit warm, but still within limits bearing in mind that the oil cooler is in place.

considering the rewiring, i rewired the engine-temp sensor, as its cable was smaller in diameter than the one of the trans-temp. that didn't change anything. i also checked the system by setting up new cables connected directly to the battery and another identical temp-gauge (water temp). same result, the needle jumps a little bit over 100°F with engine fully cold. the same happens when I swap the sensors from the transmission and the engine, since both are identical. The last plausible issue might be that the adapter plug for the sensor was installed using some kind of thread-sealant. If so, this might cause some additional resistance, thus throwing of the reading. But for now I call it the day, as its too much fumbling to screw it out and check. That's on my to-do-list for tomorrow...

 

[iains]

When you get similar results from differing data collection tools, I would take that to mean there’s a real effect being measured. One point I would make is that measuring the oil temperature before and after the cooler gives more usable data than plumbing into the pan.
From what I have read, I think you have an engine that happens to be built on the tight side of the spec range. That would suggest an oil cooler, and perhaps a lighter viscosity would oil would help. While you already have a cooler, you may need a pretty big cooler, perhaps with its own fan to transfer enough heat.

 

[mickeypowa]

If you really feel you need an oil cooler, why not just use a GN radiator with both the oil and trans cooler in it? Rock Auto part# APD 8010683. Great coolant cooling too.

I need a radiator that also cools oil and trans, are you sure this part will do the job ??
Thanks

 

[1320John$$$]

My 81 mc with diesel power had a oil cooler in the radiator with auto transmission that I later used in sbc swap worked as is and a 3 row cooler to boot

 

[Clone TIE Pilot]

I need a radiator that also cools oil and trans, are you sure this part will do the job ??
Thanks

I looked into it, and the GN rads have the oil cooler on the wrong side for an SBC unless you run really complex lines. The GN rad has both oil and ATF coolers on the passenger side. Buick V6s have their oil filers on the passenger side insteadvof the driver side like SBCs.

 

[Supercharged111]

My observations mirror that of pontiacgp's. Oil temps track within 15 degrees of coolant, often less on a DD/cruiser. Road racing is the only time I've seen oil temps spike. Based on that, I've opted to ignore oil temps on my tow rigs. They make enough juice to hold OD most of the time so I know they're alright.