High eot after switching to T6

[DT620]

I switched to Rotella T6 yesterday and before that I was just using Rotella T. I drove it for the first time today since the oil change and my eot was about 10 deg hotter than it had been in the past. I'm normally around 186 and today I was at 194-196. I wasn't driving any different from normal. Any ideas?


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[DT620]

Bump


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[twoicebergs]

Thermostat issues. Apples vs oranges. It had nothing to due with it! Or you were driving it differently.

[DT620]

I didn't think it would make it get hotter. It was just strange that it started doing it after changing to it. Wasnt driving it any different from any other time. I did add diesel kleen to the tank don't know if that would effect it either.


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[michaelaiman]

Paranoia! Unless your Delta gets outa control crazy, I wouldn't worry about it. That is, if your still on an OEM oil cooler set-up

[DT620]

My delta was running around 8* and then it was up around 18*. Oil cooler is still stock.


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[michaelaiman]

Sounds like you've got an oil cooler job in your immediate future then

[PSDMikeB]

EOT by itself does not tell the whole story. An oil temp of 186 looks to be (to me) abnormally low. The oil is cooled by coolant, and where the EOT and ECT are measured there is no way the oil can be cooler than the coolant (unless you have a BPD oil cooler, then EOT is typically lower since it is air cooled). Thay being said, your collant should be around 190 - 192 (where the thermostat opens) or a bit higher depending on the engine load and ambient temperatures. That is the starting point for the oil temperature, It should not (really cannot) be lower than the ECT once the engine is warmed up.

Was it fully warmed up? My EOT lags behind the ECT until the truck is fully warmed up.

When you first go to start up in the morning, look at the EOT, ECT, TFT, and ambient temperaures. They should all be within a couple of degrees of each other.

[DT620]

My eot was 194-196 and ect was 176-178. That was after driving for about 30 minutes. They have never been that far apart since I've gotten my CTS. Could be the oil cooler decided to take a crap at the same time as the oil change idk.


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[PSDMikeB]

Definitely a stuck open thermostat. Also looks like the oil cooler is plugged up. When the ECT goes up the EOT will also go up. The delta should stay about the same and you are passed the magic 15 degree spread.

MikeB