Hello all,i've had to top up my oil level using a quart of oil,there are traces of oil floating on the coolant in the expansion tank,there is no coolant in the oil,i have read about the common oil leaks on the sump etc,but where would this leak be ?? car is running fine Justacooper.Thanks in advance

 

bump

 

2 places to look....head-gasket.....or maybe the oil cooler....

 

Justacoopers don't have oil coolers that tie into the cooling system.... I would get the oil out of it and drive it 5 miles...check it, then drive it some more. If you've got something to worry about you'll be collecting more oil in there. Could've been some Jack*** put a splash of oil in the wrong place 1 time. Unless you've done ALL of your own maintenance you can't know for sure.

 

^take the oil out of it??? Drain the oil & drive for 5 miles? Or more? = mort. You mean get the oil out of the expansion tank. someone told a story about a gas station "person"???, putting power steering fluid in an expansion tank... there's more - fuel conditioner in the windshield washer fluid tank...

OP The cooling system should be pressure tested if you suspect a leak

 

Good point about the r50 not having an oil cooler like the r53...
One thing to consider...was it the same color as you engine oil, or just an oily substance floating on top?!
If the previous owner put some water pump lube+conditioner in the tank, some of the mixes I have seen have a bit of oil in them...
Has the level of the coolant been constant?

 

LOL, yeppers....get the oil out of the expansion tank

 

The car had an oil change 3 months ago Mobil 1 and a radiator flush,refilled with Zerex GO-5 and a bottle of water wetter,the oil colour is normal it would be milky if it had water-coolant in it,oil floating on the coolant is normal colour as well,blown head gasket well car is not missing and runs right out to red line fine you'd never had known had i not gone in there to check fluid levels.Did the work myself so it's an oil leak

 

An oil leak into the coolant - the oil would need to be comming from the head gasket oil galleys to lube the cam, yes??? If the oil source is not the head gasket - you may have a big problem.... Have the cooling system pressure tested.....

 

Kind of weird though...with the engine running, oil pressure is high and if there was a breech, we'd all agree that oil could escape into the coolant system. But, it works the other way around too. With the engine shut off, the cooling system still has pressure on it and would almost certainly be able to push coolant into the oiling system and you'd have coolant in the oil.

 

chadtoolio, It is on the odd side... This would happen with aluminum heads on an iron block - usually after some time - years - coolant would compromise the gasket @ a head bolt - stud, eat it's way to an oil source. Haven't seen this for many years - Removing 1 of these heads was, in most cases, dificult - at least 1 or more head - stud - bolt would have oxidized ( coolant ) it self to the head. It's a good thing the meterals we use today are not as suseptible to this kind of problem.

 

The obvious place to look would be a head gasket but i smoked a guy last nite and it aint misfiring or has a lack of compression,rather unusual to say the least.