boiling over after new head...help plz!!

[Simeon]

Not particularly helpful perhaps, but a quick question re that /\ I thought the expansion tank cap was supposed to release the pressure up to a point, keeping the pressure in the system constant?

[mattneck(Beavis)]

it does but it doesnt release all that air thats stuck in there.. tht needs to escape.

if run with the cap off the air comes through the system and out, keeping the bottle topped up during this period while eveything is being moved around helps to eliminate any air locks eventually

[DarnPB]

The best thing to do before filling with coolant from empty is to remove one of the sensors, the black or the blue one. This allows the system to fill from the bottom, thus pushing the air out of the top. Also when filling, squeeze the hoses every now and again to 'pump' the water around. This will help release the air.

[wopdat]

Silly question but have you checked the timing?!?! 

If the timing is out then the car will overheat and damage your headgasket!!! 

[Benrevs]

Cheers you lot it sorted itself eventually.. i just let it idle a bit more with the cap off and it sorted it.  Tis all good now, running like new 

[Conker]

Nice one - A good cheap fix for you!!

A tip for refilling coolant... If you can find out how much coolant your system holds (I think my valver holds about 4 lires IIRC), if you measure how much you've refilled it with, you'll be able to tell if you've got a major air pocket if you can only squeeze in 3 litres for example.