C5 oil temps?
05-18-2019, 08:06 PM
#1
Burning Brakes
Thread Starter
C5 oil temps?
My oil temps are getting pretty high relatively quickly. Starting off normal at around (ECT/EOT) 187/190 cruising, do a pull or two to 150 miles per hour and my temperature rises to 205/235. It then takes 5 or 10 minutes for the temperature to cool back down while cruising to 187/208. I have a 160 tstat.
Is this normal? Granted my C6Z06 has an integrated oil cooler but I've never seen such a huge differential (30*) between coolant and oil.
Is this normal? Granted my C6Z06 has an integrated oil cooler but I've never seen such a huge differential (30*) between coolant and oil.
Last edited by freddyvette; 05-18-2019 at 09:26 PM.
05-18-2019, 08:28 PM
#2
Seems fine to me! It's expected for oil to carry higher temperatures than your coolant, and to take longer to come down. Your radiator is massive, and it's aided by more airflow at higher speeds. Get an external oil cooler if you're worried about it, but for street driving it's unnecessary IMO
Last edited by Jackie N; 05-18-2019 at 08:29 PM.
05-18-2019, 09:33 PM
#5
Well if those were you temps on a track then it's even less concerning! If I was seeing 300+ then it'd be time to consider an external cooler or better oil.
At your temps even a standard petroleum base oil would do fine. But you're running synthetic of course! Right? Of course
At your temps even a standard petroleum base oil would do fine. But you're running synthetic of course! Right? Of course
Last edited by Jackie N; 05-18-2019 at 09:34 PM.
05-18-2019, 09:41 PM
#6
Burning Brakes
Thread Starter
M1 5w30. These weren't track temps but essentially a half mile pull on the street. I went to the Texas Mile and didn't break 200 F EOT on my C6. Just wondering if people are seeing the same ranges and disparity between EOT and ECT
05-18-2019, 10:27 PM
#7
Instructor
I have fan temps adjusted to come on a little earlier, otherwise stock cooling system. My coolant and oil stays between 208-218 under normal driving conditions, normally the high end of that and nearly 220s on hot days in stop and go traffic.
I see 235 oil temp EASY when I'm beating on it for a few pulls Coolant will stay below 220.. People see 300 oil temp in a few laps on track with their c5s with entirely stock systems, so your numbers seem to be normal or better
Multiple pulls in a row/curving up backroads I've seen 30 degrees difference regularly.
240F oil will cause oxidation and begin to break down oil. Its an easy and cheap task, and good practice to just go ahead and change your oil after track days, or maybe every other in the case of mile/half mile/drag events where its not REALLY getting cooked.
I see 235 oil temp EASY when I'm beating on it for a few pulls Coolant will stay below 220.. People see 300 oil temp in a few laps on track with their c5s with entirely stock systems, so your numbers seem to be normal or better
Multiple pulls in a row/curving up backroads I've seen 30 degrees difference regularly.
240F oil will cause oxidation and begin to break down oil. Its an easy and cheap task, and good practice to just go ahead and change your oil after track days, or maybe every other in the case of mile/half mile/drag events where its not REALLY getting cooked.
05-19-2019, 05:01 AM
#9
Burning Brakes
At VIR with my C5Z06, during 30 minute track intervals, the oil was at 260* for most of the session. The car's engine and cooling system were completely stock at the time and I was running M1 5W30 extended perfromance. During 'spirited' street driving, the oil temps are at 230*. During typical highway driving, the oil temps are 205*. Your temps do not seem out of the ordinary at all. My 08 C6Z06 would not get nearly as hot, but it had the first generation external engine oil cooler that would never seem to let the oil get up to good temps. GM eventually changed that in later models to get some temps into the oil. Not sure what year C6Z you have, but that may be why you see lower temps in the C6Z.
05-19-2019, 07:54 AM
#10
Synthetic can go far far hotter.
05-19-2019, 10:32 AM
#11
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05-19-2019, 10:51 AM
#12
A EOT and ECT difference like that is not abnormal, especially when you put a lot of energy into the car. Not that you should take the car that high, but I believe the warning lights for over temp are set for ~325 and ~260 for EOT and ECT respectively. 205 and 235 is nothing. Before I put in a Dewitts radiator with oil cooler I was seeing ~240 ECT and ~290 EOT at the track after only a couple laps 
Last edited by Clairvoyantwolf; 05-19-2019 at 10:51 AM.
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05-19-2019, 11:22 PM
#13
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I took my C5z to Blood Mountain today and ran the living dog **** out of it.
I have a 160 thermostat as well. Just cruising my coolant today on a near 90 degree day was 180 and oil was 205.
Getting on in the car hard put oil in the 230 range and the most aggressive part of the mountain I was at 248 oil temp. The RPM was kept in the 5k-6500 range in 2nd and third gears. Pulled into a park conveniently as the oil temp hit 248... I let the car idle for 10 minutes to shed the heat (idling is much better than shutting off the engine for heat) and oil dropped back to 215.
I have a 160 thermostat as well. Just cruising my coolant today on a near 90 degree day was 180 and oil was 205.
Getting on in the car hard put oil in the 230 range and the most aggressive part of the mountain I was at 248 oil temp. The RPM was kept in the 5k-6500 range in 2nd and third gears. Pulled into a park conveniently as the oil temp hit 248... I let the car idle for 10 minutes to shed the heat (idling is much better than shutting off the engine for heat) and oil dropped back to 215.