Extreme oil temps after ecu reset
 

So I reset my ecu today to clear the loose gas cap code, my oil temps have never seen higher than 220. When I switched to synthetic oil (pennzoil ultra), my temps dropped even more down to 210-215 at the highest. I live in texas and drove to houston and back in 100+ degree temps with no issues. But today, after my ecu reset on a 12 mile drive back home from work in 95 degree temp, my oil temps soared to 250. 260!!!! This was the first drive since I reset the ecu in the parking lot! What the #uck happened?? The car is a 2010 with 2.5k.....this is some bs! Anyone heard or had this crap happen to them so suddenly, does the ecu monitor or regulate something regarding oil cooling? Thanks /end rant

How did you reset your ECU? Resetting with an OBD shouldn't have messed with the ECU like that. You would need an access port. Where you revving pretty high I traffic? Did limp mode kick in? If you hit 260 like you said, then your revs would have been limited to 3500rpm.

Also, I think Nissan dealer uses ester oil. That's what my dealer puts in my car.

I reset the ecu using the gas press and release method from online. By the time I pulled up to my appt my temps were right at 260! Its all stop and go pretty much from work to appt...my car is garaged at work all day so I know it was cool. Right now I drove to hooters which is about 20 miles from the appt after the car heated like that, and my temps didn't go higher than 220 this time. Am really confused. I wonder if the oil temps are tied to the ecu also?!

Just hot dude

The only time that happened to me was when I was holding the revs longer than I should have. Just let it cool and it should be fine. Get an oil cooler if you plan on running it flat out a lot. Good luck.

Thanks man, once my oil temps normalize again under day to day driving, am gonna do a little test and reset my ecu again and see if oil temps are affected. Maybe some of the people that have oil temp issues are due to somekinda ecu thing...idk

Hmm. Funny enough, I thought mine looked temporarily high after the dealer reflashed the ECU's headlight autotimer setting... could be a weird software glitch where anytime the ECU is calibrated/reset the sensor misreads things until the next key cycle.

Or... maybe it recalbrates itself if you reset the ecu, leading to a potential inital misread.

If it doesn't happen again, I'd chalk it up to goofy software issue and not worry about it.

Disconnect the negative terminal on your battery for 10 minutes. Then you'll be sure the ECU has cleared completely with no odd issues.

Best way to reset, but all a reset really does is Zero out the fuel trims and reboot the computer. Fault codes remain and don't completely disappear unless cleared with an OBD tool...though the CEL may go out.

thanks for the replies everyone. The oil temps seem to have leveled off again to 210-215. I even drove a little hard, extended my route and the temps wouldnt budge. I'm gonna reset the ecu again on sunday and go for a drive, if the oil temps soar again, then i might be convinced that some of the oil temp issues could be ECU related. I'll report back!

Really? Does that mean if there's multiple trip detection logic it will throw a CEL again soon? :shakes head:

Let us know. I bet it has to recalibrate itself. Some ECU's after a reset cause temporary hunting at idle for similar reasons.

Yeah...faults are stored in Non-volatile memory. Unless the cause of the fault is corrected it will likely come back.

Fuel trims will re-calibrate naturally...It usually takes from 25-50 miles for the Long term trims to re-set. You have constant correction of the short term trims though which eventually build a table for the long term numbers to be set

hey guys i just put in pennzoil utltra too, and now seeing temps in 260-270 when driven hard, was doing 110 going to new branfels tx and temp hit 270, only change was oil, nissan dealer said it might not be formulated for hard driving with our valves. I'm going back to ester and just change every 2500-3000 (temps stayed under 220 even when driving hard.

If you're dumb enough to drive 110 on the highway, you can deal with those temps.

i dunno its different down south i was on a packed highway in Tennessee yesterday in a 55 and i had to go 80 to remotely keep up with traffic it was like no one wanted to slow down (or use their F'n blinker).so if texas has some of those same moments, or is anything like driving through montana 110 is reasonable. it is probably easier to go fast on our highways than it is on the autobahn because tome states are just full of straight boring roads, you just need little to no traffic.