ZachCivic

So I'm still seeing some oil in the coolant after a head gasket change. Did a block test before I cleared the car and it was good (also did it at 3000 rpms idling). I flushed the coolant like 6 or 7 times and drove the car about 5-10 minutes at warm in between flushes. Then I put in Type II and I'm seeing some oil in the coolant still. It's a slight rainbow film in the overflow and a small amount of sludge lining the radiator cap and top of the radiator. Is this still normal to be circulating the residual oil from pulling head or could this be worse? We got a lot in there, but the last flushes didn't look like there was that much oil in them. Some of the flushes were only if the car was idling until warm and not under load.

ezone

It's a huge freekin PITA to get all oil out of a cooling system! It can stay hiding in there for a damn long time.

Leftover oil in the cooling system can ruin everything made of rubber like hoses and cap and some gaskets.

Try mixing up some detergent (maybe Cascade dishwasher or a laundry detergent, something that will not make suds) with water as a flush a few times followed by plenty of plain water as the rinse?
(google transmission cooler failure, maybe you can read more about ideas to clean an oil contaminated cooling system that way)

Idling isn't enough IMO, revving up needs done to get this hot and circulating rapidly and thoroughly. The detergent has to kinda soak up oil residues as it circulates, but it would be nice if it could actually scrub the insides though LOL

I'd say try some Dawn, but that will make hella suds and that might cause even more overheat problems on top of everything.