Ford Focus 1.0 Ecoboost - Expansion tank emptying

[goodallt]

I had the engine replace 12 months ago due to known issue (degas hose failure)
The car runs fine in normal traffic, but if I stuck in traffic it overheats (although temp guage doesn't show it) and I have to top up water/coolant in expansion tank

There is brownish spray inside boot but can't see where it's coming from

Any ideas? Is there possibly a blockage in the coolant system?

Edited by goodallt on Thursday 14th November 11:46

[sunbeam alpine]

[quote=goodalltThere is brownish spray inside boot...
[/quote]

Do you mean under the bonnet?

I would expect that you would have constant problems if there was a blockage in the cooling system.

Does the fan come on when the car is in traffic?

Sometimes you can save the situation by turning the car heating right up and setting the blower on maximum - may take enough heat away from the engine to get you out of trouble, but obviously isn't a solution to the problem.