coolant res tank FULL of oil !

[Passat2003]

OIL COOLER,remove the oil cooler pipes and bridge the them with some tubing,remove thermostate and refit the housing so the engine can be run,remove the coolant header tank and clean out ,refit the header tank and leave the return pipe off and direct the pipe to a large bucket.With a hose pipe run the engine and keep a supply of water running into the header tank as the returning water will drain into your bucket.Run the engine and monitor the oil circulating if it decreases its the cooler.Run some coolant cleaner through ths syatem and fit a new oil cooler.Change oil and filter and reflush after 1000 miles,refit the thermostate.Long winded and dirty dirty job

Brilliant thanks very much for your (and everyone else's ) help. I had visions of a second mortgage looming for a head change

If you don't mind me asking, Just to put my mind at rest , given the symptoms, what % chance would you think the problem is the oil cooler and not the head. ? bearing in mind the amount of oil and the fact that its black and not brown & frothy.

Thanks again all

[Crasher]

Oil in the coolant is the cooler. The oil runs at 2 bar and up, the coolant at about 0.1 bar so the oil will go into the cooler. Head gasket failure is a problem on these but you get coolant in the oil. Do the cooler first, I am 99% sure you will be OK.

[a8 tech]

99% oil cooler.Head gaskets very rare crack in the engine even rarer turbo would have other issues,one being excessive smoke and possible over reving