Thanks Sewin, to answer some of your questions:
- it's not aftermarket as far as I know - it is identical to the old one (which I no longer have), s fitted in the same place and has the same capacity. I did notice that the new cap is different from the old one. All was fine prior to the work being done - have had it for a year and it drove well without cooling issues.
You are right though to ask if the car is actually boiling - I think it is just that at 100 degrees it is not pressurised, therefore not keeping the coolant in.as it should. The car is not overheating and there is no white smoke in the exhaust, no mayo in the oil cap, and the coolant does not smell of exhaust fumes. NOw that the level of coolant has dropped, it is not actually venting coolant, just steam, which stops when the fans kick in. I might just see if I can get another cap tomorrow and test it that way. Would be quicker than taking it back to New Elms which is a 90 min drive.
I will keep you all posted.
Mark
