Originally Posted by
reds919hornet
I work on cars for a living and bikes for fun so I am not 100% sure on this but the pressurized oil that goes up to the head and cams goes through a dowel pin at the head gasket and is hard to make it leak there. the oil gets into the coolant at a point where the oil pressure is higher than the 15 lbs or so that the cooling system is running at when it is up to temp. the oil returns coming from the head go through just the head gaskets but it is not under pressure and that is why when a head gasket blows you get coolant in the oil.
not impossible for it to be a head gasket but unlikely. oil cooler is where I would start. looking at the service manual it doesw not look like oil is under pressure around where the water pump is at. I would almost put money on oil cooler problem.
I agree with you, you're on the right track.
But i'd start from waterpump, cause like you said...headgasket can leak coolant into oil, not the other way around. On 636, waterpump and oilpump are connected, the are on the same rod just one side pumps water, other side oil. If the seal or waterpump itself goes bad and waterpump side is not working...you dont get that much pressure on that side and oil pump starts sending some of his pressure thru the seal into coolant. And thats and easy check, just remove the waterpump cover and see whats under there.
