BlackOp

I have oil residue in my coolant tank but the actual coolant looks clean. I flushed the system twice (5 months ago) when replacing the alternator and didn't notice anything the looked suspicious. Is oil in the coolant obvious...meaning you can see the mix when inspecting the fluid? It still looks new. I'm just wondering if this is just old deposits passing through the coolant system and ending up in the tank.

Thanks,

Grandpa#3

Hi, Is there oil floating on top of the anti-freeze in the coolant reservoir? I would keep an eye on the reservoir to see if more oil appeared and if the fluid level changes. Others may have more information.

Cheers,
Larry

andys-944

In my NA the oil did get pretty well mixed in the coolant, not just floating on the surface.
After replacing the seal the system was flushed three time before we didn't find oil in the tank.
Not sure this helps, they may be old deposits, although why would they surface now? I'd watch it for the next couple of short trips before declaring the seals leaking, and obviously keep checking the oil.

BlackOp

No oil floating but my white expansion tank had residue..a thin layer of sludge. It's been like that for a year. The PO replaced the rad/HG/rod bearings 6k ago. Obviously something went south back then but have no idea if the expansion tank was purchased before that particular failure. I just noticed an oil "ring"..similar to a dirty bathtub. Could this previous expansion tank residue just recycle when the coolant gets hot?

I guess I'm curious if there is a lot of oil in the coolant when these seals begin to fail. My actual coolant looks new and not discolored.

ernie9468

Probably just old oil deposits ,very hard to flush completely once oil get mixe up with coolant.But still keep a close eye on it.Did happen to me with my ex 944 when the oil cooler when nuke and even though I flush the the expension tank several time oil trace kept showing up afterward.

BlackOp

Thanks...I'm assuming the PO did the OC seals when he resealed the engine. He was a pretty meticulous guy and said all front engine seals were replaced...owned the car for 10 years. I'm going to flush to system a few times tomorrow.

I wonder if prestone super flush is safe..all the seals are new. I might try Shout/dishwasher detergent too..

ernie9468

Problem is that oil deposit tend to stick to the expension tank wall & are very hard to dislolge even after a good flush you still migth have traces of oil in there.Prestone Super Flush is very strong stuff & you should be carefull when using it that it doesn't hurt components of your cooling systeme.Personally I will go with Permatex 80032.

ZW 944

I had the oil cooler seals blow out on my 86 turbo last year, and it became more and more evident over time, very obvious. There was first oil in the coolant, then went to having small amounts of coolant in the oil, before I was able to get it fixed.

black944 turbo

Check the oil cap. If it is frothy at all probably a good bet coller sealers and or head gasket. When mine failed it was frothy in the oil cap only and continued to get worse. At first it apeared to be normal condensation from sitting (my car is not driven much), however as ZW said it became obvious over some time.

BlackOp

Did a full flush today...the 6 month old coolant looks clean..it's a bit dark as I mixed purple/green coolant. I didnt see any signs of milkshake or oil.



You can see the residue line on my reservoir..it's what got me worried. I'm chalking it up to old deposits..



What do you guys think?

Fara

Looks like old residue from a similar failure to me