Yes, it is the can of worms I don't fancy opening - get the head off and it is still not fixed. Price to fix is more than the car is worth

I would agree that it's not worth actual work to fix. You could try Barrs Leaks or similar - it does actually work (I used it on my old MGB V8 which had a HG problem that I wasn't going to pay to fix, it ran perfectly for a year with no overheating etc before I sold it).

It's a shot to nothing - if it fixes the problem it's cost less than a tenner. If it doesn't fix it, it's cost less than a tenner.

Yes, I wondered about that, and I'd agree its worth a try.

However, IF I understand how it works, expanded ginger root fibres get swept into gaps by the flow of coolant, and block them.

That sounds like it might stop coolant leaking OUT from the cooling system, but might NOT stop pressurised oil leaking IN to the cooling system, which seems to be whats happening.

Oil in coolant probably won't kill an engine very fast, unless it severely overheats. Coolant in oil, OTOH, could cause rather rapid destruction.

If you decide to live with it, it'd probably be a good idea to keep an especially close watch on your oil.

Maybe start using the blotter spot test, which is said to be sensitive to glycol contamination

Thanks for all the input.

I had thought of using Barrs or K-Seai but unsure if it actually applies in this case. The oil doesn't appear contaminated (mayonnaise) but that's not a definitive diagnostic. The oil level warning popped up over the weekend, but the coolant seems OK. I do get an occasional warning for coolant but the mechanic reckoned that the coolant hoses have softened due to the oil contamination thus expand when hot coolant passes through and sucks coolant from the expansion tank.

The car is not overheating - probably slightly over-cooling

I have decided that I need a new car so how long could I expect the old girl to keep on going?

Yes, the coolant is sludgy again even after a change of the oil cooler - the oil cooler had been leaking on the seal to the engine so it was presumed that this had failed internally.

As the sludge had returned and was / is more than might be expected as residual from the first flush the garage suggested the HG has gone. I would hope the replacement cooler is not faulty, but I could incur more re expense if found to be OK rather than covered by the warranty