Oil in the cooling system

[JonnieSix]

Hi folks,

About 2 months ago my Passat B5 100bhp tdi, decided that the engine oil needed to be in the cooling system, on the advice of a friend i changed the oil cooler, flushed the cooling system the best i could, changed the engine oil and filter, and finally built it all back up.

the oil cooler used was not a geniune VAG part, but an after market piece, after running it for a week or two, all seemed well, no leaks etc, then the day after a run to Sheffield, the car did the same as before, warning lights flashing like a bad disco, and i'm left with Oil in the cooling system again.

So my question is, what apart from the Oil cooler blowing the seam between the chambers, what else could cause it?, because tbh i'm confused as ****, and frustrated to boot =(

Thanks in advance for any help, Cheers

[zollaf]

oil cooler, head gasket or a cracked block or head. the oil runs at a far higher pressure than the water does, hence oil going into the water. first thing i would do is to take the oil cooler to an engine place and get it pressure tested, making sure they put pressure into the oil side as a leak can and will be one way only. the fact it cleared up for a week suggests your mate was right and maybe the new one has failed, probably because its been knocked up in china from bits of scrap metal found laying about. could be the head gasket but i have never known one fail like this myself.

[JonnieSix]

Yeah thought that myself tbf, can't see it being the head gasket, as there's no water in the oil and no creamy mixture in around the top end, so hopefully it's just the cooler again, =/,

Cheers mate