coolant tank lined with black.... hmmm

[c9000]

I had the coolant level warning lighting up a fair bit driving my 9k home from work yesterday so topped it up this morning. That's the first time it's happened since I purchased the car in July last year (I have topped up the coolant a few times) and when I looked in the tank this morning the level was way down towards the bottom.

But before I refilled the tank, I had a really good look inside and rubbed my finger inside it to figure out what the grey goop covering all the internal surfaces was. It's definitely oily but there is no contamination of oil with coolant and there doesn't seem to be any evidence (that I've found) of crankcase gases getting into the coolant system. It didn't have an immediately obvious oil smell.

However the car ran find today apart from the shifting difficulty which I suspect could be one of three things - clutch (probably needs a bleed), shift rod coupler or the shifter mechanism itself. Still need to investigate that.

Anyway back to the coolant. I have obtained a brand new replacement coolant expansion tank and am going to give the coolant system a complete flush tomorrow as I always do it with a car that's new to me and wanted to wait until I found a new tank before I did the job. I'll be using my standard coolant to replace the old fluid - namely a 1:1 mix of Nulon Long-Life Coolant (meets the Saab spec) with water.

I am not sure where there might be a coolant leak as none of the hose connections in the engine bay that I could see this morning when the engine was cold were showing evidence of coolant loss.

Craig.