# Oil in Coolant.



## TylerRatTV (Nov 27, 2014)

So my 09 (Holden) Cruze thats done 126000KM after a 2000KM round trip has decided that it not only wants to leak oil out of the valve cover but it now has decided that the coolant should be oil to. 
Has anyone else had this problem before? and what was the fix? or is my car destined for the crusher?

Thankyou.


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## S-Fitz (Jul 16, 2012)

Bad head gasket?


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## Eddy Cruze (Jan 10, 2014)

Cracked Block or Head?


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## jblackburn (Apr 14, 2012)

Run a compression test and see what that tells you.

I am not sure about the 1.6/1.8 motors (or which you have), but the 1.4 has a oil-to-coolant heat exchanger, and these have been known to leak in other applications.


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## TylerRatTV (Nov 27, 2014)

Probably should have said that its a korean built 1.8L auto


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## grs1961 (Oct 23, 2012)

Stop driving it, get it to a mac, you have either blown a head gasket or cracked something.


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## Robby (Mar 1, 2013)

Coolant intermixed with engine oil is usually a failed head gasket......not at all uncommon on engines using a cast iron block with a aluminum head.

But I am reading your question as 'Oil in Coolant'.......if that is the question, then you very likely have a failed transmission oil cooler, which is located inside the radiator.
In this case, the trans fluid, which operates at a higher pressure than the cooling system, migrates into the coolant......hence, 'Oil in Coolant'

#1 Generally requires a head gasket and two oil changes....one immediatly after the repair and the second one within 50 miles of the repair. The second one is to get any remaining intermix out of the oil that was trapped in the various passages during the repair.

#2 Requires a radiator replacement and a thourough flushing of the cooling system and the trans fluid restored to the correct level after being certain there is no reverse intermix.

Coolant in engine oil looks like a chocolat milkshake.

Coolant intermixed with ATF looks like a strawberry milkshake.

ATF intermixed in the radiator looks like a strawberry colored oil slick.


Rob


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## spacedout (Dec 7, 2010)

mmmm.... strawberry milkshake.


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## MCMS (Jul 4, 2015)

Rob all thanks for your advice above. 
I have some questions on the Chevy Cruze oil in the coolant problem. 
I just bought a 2011 Cruze with a 130K miles and oil in the coolant. She starts, but I do not want to run it until this is fixed. 
Looks like a great little car with a little work and I know just a little about cars and figured this would be a good one to learn on....
So I hoping to learn from the forums and U-tube to repair and maintain. Here goes my questions....

Compression test, looks easy enough just need to get a gauge. So if one or more cylinder's fail, what next???
and at that point do I open it up to look at the head Gasket? 
with regards to the problem being a transmission fluid leak, How do I know what caused the leak? I really do not want to replace all the gaskets and not fix the cause? 
Thanks for sharing your knowledge. 
MCMS


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## ChevyGuy (Dec 13, 2014)

MCMS said:


> with regards to the problem being a transmission fluid leak, How do I know what caused the leak?


There's only one place where transmission oil can mix with the coolant - and that's the transmission coolant loop inside the radiator. Replace radiator, and the cause will have been replaced. The other items Robby mentioned is to cleanup/limit the damage.


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## NickD (Dec 10, 2011)

One detail missing from this story is whether the engine was permitted to overheat at any time. One possible cause is that the heater core is now a very important part of the cooling system. This is starting to ring some bells, use to add a safety bypass valve to prevent this, don't recall seeing one on the Cruze.

Robby brings up a good point with AT cooling, use to have two radiator repair shops in town that went bankrupt now that plastic and aluminum replaced copper and brass. One of earlier throwaway parts. Generally rig up an air compressor to the inlet, block the outlet, and check for air bubbles in the coolant, a lot more inconvenient since they elected to dump the radiator cap, but should see bubbles in the recovery tank with the cap removed.

Use to repair my condenser, evaporators, heater cores, and radiators, now I have to get out my credit card. Key to a good cooling engine flush was getting at the block drain plugs. Still using block drain plugs, but can't get at them with that transaxle in the way.

Ha, now have to check my Cruze for a heater core bypass. But you know its not working if not getting any heat, Plugged heater cores are becoming quite the problem today. You don't block them, need a hose to bypass them, try this with quick couplers.


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## CrazyExpy (Apr 2, 2016)

Have this problem on a 2013 Sonic and the issue is the oil cooler has failed. located behind the exhaust manifold. This can and will ruin your engine and is not covered by the powertrain warranty!


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## zorro128 (Sep 3, 2016)

I know it is old subject but I have issue with Cruze LS 2010 1.6 engine / Mileage: 93 000 km

Recently I have replaced a pressure/sliding plate. After that I have noticed oil in coolant. Mechanic flushed the coolant and put new one. No oil now in coolant.

After that my car is loosing coolant/water. Also I can hear some sort of noise on driver's side. Noise sounds like the air is getting inside the car.

My mechanic is not able to determine loss of coolant. There are no visible traces of leaking.


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