oil in radiator

[store615]

Head gaskets were redone before I bought the car. Oil is visible in radiator, no water visible in the oil .

Where should I start?

Thanks

[penth2o]

You may not know what was done before you bought the car.....

Drain & flush every liquid in the thing and start over like you just bought a car that has sat for 20 years in a field....

It's kinda like:

"It ran fine when I parked it" I swear....

Then diagnose.

[02for2]

Headgaskets may have been redone, but that doesn't eliminate the possibility the new one isn't leaking. If the head wasn't checked for true and skimmed, it may not have properly sealed with the new gasket. That's unlikely, but still a possibility.

More likely is that while the PO may have swapped the head gasket, he may have failed to flush and refill the cooling system.

I would start with that. Then do a compression check as a baseline, and watch each over time. On the compression check - don't pay as much attention to absolute individual values as to consistency between all the cylinders.

My suspicion is that you do not have a problem, but doing these two things will pinpoint it over time if you do.

Cheers!

[thehackmechanic]

To clean the oil snot out of the cooling system, I used to flush the system, then fill it with straight water with a good squeeze of Dawn dishwashing detergent ("takes grease out of your way"), then put the car through a few warmup cycles, then as the shampoo instructions say, rinse and repeat. Make sure to turn the heater on so you're flushing out the crap in the heater core too.

[TobyB]

An oil leak to the water jacket requires a seal failure at the left

front of the block, where the oil comes up to the head.

Everywhere else it flows the other way, coolant being under pressure

and all that.

And it's pretty unlikely- BMW worked hard to prevent it.

So clean things out well (I like Dawn dish detergent, but I'm wierd)

and keep an eye on it. If it doesn't spit much, it won't kill anything.

Oil in the water just lubes the water pump!

But odds are in your favor that it's just residue from the head gasket change.

t