Oily bubbles on green coolant

[Mulliner GT]

A friend is about to buy a '04 E46 325 cab auto. Looks and drives ok but coolant is green and has some (not too many) small oily type bubbles which are very small and coolant is a very little sticky. Climate control heats up car quickly enough and temp needle sits bang in the middle. No records to show when coolant has been last change either. Is this the symptoms of Head gasket failure?

[E30M3SE]

Possibly, yes, or it has had the problem already and the cooling systems neeeds flushing out (again?)

The car being an auto it could also be ATF fluid, as the radiator also cools the box via a heat exchanger.

ETA; BMW supplied coolant is blue not green, if the car has FBMWSH, then someone else has been in there.

Edited by E30M3SE on Thursday 25th March 09:45

[john_p]

If the engine oil is fine (not milky) I would suspect ATF heat exchanger failure, either now or in the past

I had this on my '00 328 at about 125k, and even after several flushes there is still orange/yellow oily bubbles in the coolant.

If it has been replaced (explaining the non OEM coolant) then there might be some leftover contamination - if the heat exchanger has properly failed then you'll get loads of yellowy gunk in the coolant and accumulating on the bottom of the expansion tank cap.

The thing to wonder is also whether the coolant has got into the auto box causing the potential for premature failure.. I don't know if this is a reasonable fear or not given the pressure differential between the two systems, someone else may know more

Edited by john_p on Thursday 25th March 09:53

[E30M3SE]

Any mayonnaise type crud on the inside of the oil filler cap or on the dipstick?

Are the coolant pipes rock hard when the engine is up to temperature?

Test the coolant for combustion gases

Back street servicing, no history or paperwork, I would find another car unless this one is seriously cheap.

[Mulliner GT]

Thanks for the replies. Oil filler cap and dip stick are clear no mayo anywhere. There is a dampy smell in the inside of the car come to think about it. Will get garage to check for HG. Car is a lot cheaper than it should be, cause its unloved, clonky suspension, needs tyres and a few dents sorting.

[LeightonBuzzard]

It could just be to the fact it's a silicate based coolant which lasts for 3 years, which BMW's need unlike the pink longlife, non silicate based stuff that VAGs use which lasts for 5 years.


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[Fox-]

Mulliner GT said:

Thanks for the replies. Oil filler cap and dip stick are clear no mayo anywhere. There is a dampy smell in the inside of the car come to think about it. Will get garage to check for HG. Car is a lot cheaper than it should be, cause its unloved, clonky suspension, needs tyres and a few dents sorting.

Walk away. You do not want a bad BMW.