HELP! Oil in expansion tank after replacing cooler

[maddar88]

Got an astra sri 1.6 that had upon inspection a milky oil shake floating on top of red coolant. Ive changed the cooler and put in new coolant, but the problem returns shortly after. The car driver fine, no overheating, aircon blows hot, no coolant or warning signs on dash.

Is it a case of old residue making its way up to the expansion and needing a proper few flushes?

Ive bled the radiator to see if the coolant is clear and it is. Engine oil golden and dipstick same.

Im thinking its a botched cooler job or it needing few flushes

Please help, im at wits end

[stevieturbo]

when there is oil in the system, it really will need a thorough cleaning ad flushing to try and get it clean.

So a lot depends on how well you did clean it, and how much there now is in the header tank.

Whether you try and flush with some sort of detergent, de-greaser etc etc, it will take a lot to clean. And it needs to be clean as the oil can damage any heater/radiator hoses etc.

[maddar88]

stevieturbo said:

when there is oil in the system, it really will need a thorough cleaning ad flushing to try and get it clean.

So a lot depends on how well you did clean it, and how much there now is in the header tank.

Whether you try and flush with some sort of detergent, de-greaser etc etc, it will take a lot to clean. And it needs to be clean as the oil can damage any heater/radiator hoses etc.

Thanks steve, i havent used any degreaser. Do you reckon that this creamy residue is the leftover from the system and that it isnt most likely hgf? Especially after when i ran the car this afternoon and opened the cap (carefully as i know its hot) it was clearish liquid with creamy froth on top

Im left shocked at how much residue could be left over still, am i looking at a few flushes?

[stevieturbo]

A lot depends on what you call a flush.

At an absolute minimum I'd be blasting a hose through it to run as much fresh water through each part as best as possible, then adding some sort of detergent. Flushing both forwards and back.

Definitely clean/flush the radiator separately first, or it might even need replaced.

Likewise for flushing the heater core.

You can get good engine de-greasers that are water soluble, these are very good as they will remove the oil...and be easy washed down to clean again without any silly chemicals

[maddar88]

Do you reckon based on the symptoms that this is just that and not a hgf? As the car drives normal otherwise

That is my dreaded worst fear

[E-bmw]

maddar88 said:

Do you reckon based on the symptoms that this is just that and not a hgf? As the car drives normal otherwise

That is my dreaded worst fear

You are asking people who can't see it to come up with a definitive answer from a distance & we can't.

You need to take it somewhere competent to diagnose it correctly if you are worried about it.