Buckeye88

Hoping someone can point me in the right direction. I have a 1985 4+3. Picked it up 3 weeks ago.


It has finally been nice enough in Ohio to take it for a longer drive. My office is a short 25 minute highway commute at 70-75 miles an hour. Coolant sitting at 205 (which I understand is good), but my oil temp hit as high as 256.


While I have researched the forums for answers, I see multiple answers on an oil temp standard. I have seen that oil begins to fail at 270 degrees......I'm getting too close to that number.


I'm not losing power, and she isn't making any noises that I can identify.


Thanks

WVZR-1

The fact that the car is "NEW TO YOU" I imagine you need to start from scratch and evaluate both the sender and the cluster. Expected TEMPS and resistance values are in the FSM. Maybe with your particular set of circumstances just replace the sender and then check.

There's many '85 owners and many other early L98 owners that can maybe post their "typical" TEMPS for comparisons but being "NEW TO YOU" I'd think you evaluate "YOUR STUFF". Does your car have the AUX FAN, OIL COOLER or Z51 RPOs? It would be likely most interesting to compare cars with similar options.

Buckeye88

Thanks WV, I agree that there are many variables, I do not have an aux fan, oil cooler or Z51 package. I do need to pick up both FSM's, just haven't done it yet.


It is "New to Me" and I love this car. That being said, I have waited 45 years to have my very own Corvette and I don't want to blow it up before or after I can get the FSM. Just wanted to see if anyone here may have some insight.


I do agree with what you said.

Patsgarage

I think I remember reading somewhere that the non Z51 cars do not actually have an oil temp sensor, the computer gives a value based on other inputs. I might be thinking of the C6, but someone here will chime in. I do agree that if that is the actual oil temp it is too high for normal driving.

Cjunkie

What oil are you running?

vader86

If oil is getting to that temp, it will be dragging coolant temperatures with it.

If coolant was 205, oil was not up at 260.

Exactly how did the oil temperature behave according to the dash readout during the drive? I suspect there is a temperature sensor issue.

ex-x-fire

205 is high at 70 mph, it should be 10 degrees cooler in that situation. Most likely debris in between the radiator & the a/c condenser. Lower that coolant temp & the oil temp will go down as well. Oil temp does run higher then the coolant, it just takes some time to get there.

mazdaverx7

If you bring it by I'd be happy to go through the car with you. You're just over an hour away and I think it would be a fun day to go through the car and toss some food on the grill.

383vett

The oil temperature sensor is above the oil filter on c4s.

Patsgarage

OK, I must have read it regarding the C6. I knew someone here would know for sure.

A Peter C4

My 94 C4 base,no oil cooler, runs oil temp runs 205-215 on gauge when water is at 188-195, but I should verify that useing digital gauge readouts I used to display weter-coolant temp on digital all the time before a coolant flush and proper rad.fin cleaning that's when oil was about 215-220 and water was 200-220+ at times, but yes that oil temp is very high even for synthetic-Mobil 1

Buckeye88

I changed the old oil out with 10w-30 high mileage, I was getting some blue smoke at start up and my mechanic recommended to go with a heavyweight oil for 1,000 miles and then change to a synthetic.

Buckeye88

The oil temp climbed much slower than the coolant temp according to the dash. The coolant temp leveled out once I was on the highway, but the oil temp kept climbing. It didn't start to drop down below 240 until I was off the highway and moving at slower speeds. I'm hoping a sensor change will help.

Buckeye88

We used to store our sailboat in Vermillion when I was a kid. I forget the name of the bar on the side of the bridge there....McGarvey's? I would love to take you up on the offer. Will send you a PM.

mazdaverx7

It was but it's now Quaker Steak and Lube. Not as good as McGarveys. Any time you want give me a call and drop by. We can grill out and bust some knuckles on your car. We can always take the car up to my work and use the lifts and alignment rack and all the flush machines. I'm happy to help you get the car where you want it!!

Cjunkie

The issue is your mechanic. Drain it and change to Mobil 1 0w-40. Problem solved.

vader86

This is normal behavior, but if oil kept going to 260, then the coolant would be going with it, even at speed. If the temperature was at all erratic, it would definitely be the sensor, it will read every which direction if its dead.

I would change that sensor out, and see if the behavior continues.

205 on the highway at speed is a little high, that is a separate issue to fix. Its likely that the space between the radiator and condensor is blocked up with leaves and debris. You have to remove the shroud to clean that, but it is not difficult.

A Peter C4

My old drag race engine builder once told me that if oil temps are above normal that it's sign of bearings going bad causing high oil temp, freshen engine before things get worse and more costly

xrav22

Do you have the oil cooler/warmer, if you do the hoses get clogged at the engine enterance(clotheshanger will do the trick).
I have seen 230 ish but I never went over 235, I also have an auxilary fan switch at 210 instead of 238. I put in a thermostat of 180 also. Oil usually stays around 220 on a hot day.
Good luck

ex-x-fire

Listen, if he's running a coolant temp at 205* at 70mph and it isn't even summer yet, he's naturally going to have high oil temps. Fix the air flow problem first.