# Only oil is overheating



## carrillr7 (1 mo ago)

I have a 2011 Chevy Cruze LT turbo and there is an excessive amount of heat coming from under the hood. Dash coolant gauge is normal. Checked thermostat operation with live data obd scanner. No coolant in my last oil change. Synthetic Oil is degrading and breaking down A LOT quicker than normal. Radiator fan runs on high and loud. Fan also continues to run after car is turned off. I've also noticed that my front catalytic converter is only approximately 1cm away from the oil pan without a heat shield. Not sure iff this 1cm distance and no heat shield is by chevys design or not. I'm leaning towards the catalytic converter temp being the cause of my oil overheating. Has anyone ever experienced something like this? Any ideas or thoughts?

Rob


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## MP81 (Jul 20, 2015)

How, exactly, do you know your oil is overheating?


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## carrillr7 (1 mo ago)

It's only an assumption on my end. And that assumption is mainly based on my radiator coolant not overheating.


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## snowwy66 (Nov 5, 2017)

Oil can't get hotter then the motor or coolant. Although the theory is it can. I've yet to see it.

As for your fan problems. Lotsa threads on that very problem. 

2 temperature sensors.
Thermostat and housing.
Fan itself. There's a resistor pack on the fan motor assembly.


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## NUMBER2 (May 23, 2019)

Your cat radiating/convecting heat to the oil pan will not make the engine oil overheat. There is not enough energy there to make that happen. On that I can assure you. Coking oil in the turbo after a hot shut down is a thing, and is cumulative over time. That's why most turno engines these days require synthetic oil.

It's well established that the Cruze is calibrated to run high coolant temp, though I don't know what kind of oil temp is "normal" for a Cruze.

Sent from my SM-G781V using Tapatalk


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## Valpo Cruze (Feb 23, 2014)

snowwy66 said:


> Oil can't get hotter then the motor or coolant. Although the theory is it can. I've yet to see it.


Oil can and will get hotter than coolant temp depending on the driving conditions. The coolant circulating is removing heat from the engine to cool the engine. My Wrangler has a dash readout of trans, engine oil, and coolant temp. Once up to temp the engine oil is typically a bit hotter than the coolant temp. Drag racers will see oil temps of 230 - 260F while the coolant is still much lower than that.

Now back to the OP, if the fan is running all the time then chances are that you have a problem in your cooling system. The early Cruzes ran a bit on the warm side at 190 - 225 F, if your temps are above that then you have a problem. Start with a coolant flush and replace it with a 50/50 mix. Clean the radiator as its almost 12 years old and possibly packed with crap thus reducing its effectiveness. Could even be buildup on the AC coil in front of it. Even though you are seeing the t-stat open it may not be opening enough, might need a new t-stat and water pump.


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## chilehed (Sep 3, 2020)

carrillr7 said:


> Radiator fan runs on high and loud. Fan also continues to run after car is turned off.


Any codes?

Safe oil temperature is a lot higher than most people seem to think. In the Arizona summer it's not hard to get to 120C (248F), which doesn't bother me at all.


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## Johnny B (Jun 4, 2019)

Even though most of the posts are pretty good, I'll attempt to fill in the blanks.
First off, you should have an oil temperature sensor that you can read with an obd tool.
The oil temperature should approach about 230F the longer the engine is run. Depending on engine load, speed, and ambient temperature it will vary. If it gets above 240 F this time of year, ya you may have an issue.

It is likely you only have one issue, your radiator fan has a bad resistor bank. This will only allow the fan to run in high speed, and will turn on at a higher than normal temperature. The resistor is not replaceable, the entire fan unit will need replacement.


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## carrillr7 (1 mo ago)

chilehed said:


> Any codes?


The only code was the 420 cat code but that went away over a month ago after cat cleaner.


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## Cruze CTRL (Sep 16, 2021)

Any chance of performing a surgical procedure on the fan with one of these?


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## carrillr7 (1 mo ago)

Cruze CTRL said:


> Any chance of performing a surgical procedure on the fan with one of these?
> View attachment 300579


Heck yeah! Great find!


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## Valpo Cruze (Feb 23, 2014)

Run a search on the part number and you can find many sources not in Europe / Asia that should have faster shipping. Even Amazon has the part.


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