oil in the coolant....

[shouldi2]

hi new to this, just brought my first bmw a 1997 316se auto salloon with 91,000 on the clock and main dealer history.
when i got the car i took it to an independant bmw garage to have a inspection 2 carried out as well as some extras done in which they changed all fluids including the gearbox, rear axle etc....
when i went to check the levels about a week later i found oil in the radiator water, they drained this and refilled with fresh anti-freeze in the service.
the car drives perfectly and uses not water and does'nt seem to use any oil either, does not over heat even when stuck in heavy traffic.
so went to my local garage as i thought it was the head gasket which they checked and said was fine.
just wondered if anyone has any ideas, i was thinking that may have used an oily pot to put the anti-freeze in but that would be to simple im sure.
would be greatful for any help.

[jnstrcklnd]

Did it ever have a headgasket done before you bought it? Maybe it has oil reisdue in the radiatar from this.

[shouldi2]

not that i know of, its got full history with no mention of it.
gonna give it a flush through and start fresh and see if it returns......