mgf trophy 160 boiling problem thinking air lock

i have changed the head and everything ie gasket bolts water pump timing belts now got a boiling problem any ideas i have been told its an air lock and theres 3 points to bleed from ... i dont know where these points are can anyone help please ?

First one is on the top of the radiator, right hand side as you're looking at it. Second one need you to remove the front bay plastic cover, that sits just behind the brake servo. You'll see a bleed nipple coming out of more or less the middle of the bulkhead.

The third one is hardest to get at but not impossible. Lift the inspection cover and it's on the metal pipe on the nearside of the engine. On mine at least it's just an M5 bolt, so an 8mm spanner or socket. I found a 1/4" drive ratchet & a long extension made it easy to access.

HTH

thankyou very much for your help i will try that .. cheers mick

Make sure the auto bleed valve is working, it's inside the inlet manifold where the small coolant hose fits from the top of the header tank.

If you remove the small hose at the top of the expansion tank you should be able to blow down it (with resistance as there is a small ball valve to restrict the flow but this allows air in the system to escape to the highest point.

Other thing to check is if the thermostat is opening!

Brian.

Also Bleed the Heater (centre one) with the control to full hot, keep the expansion bottle full whilst bleeding. important to check the 'jiggle valve'' in the manifold too (did you check this when the manifold was off??
Finally replace the cap on the expansion bottle, these are notorious for failing and causing boiling.

whats the jiggle valve ?

aka the auto bleed valve as described by Brian in post above. :yesnod:

ive done all 3 and ts still boiling but everything is circulating now ... the valves were not done when the manifold was off was off no . i am again at a loss ?

sorry the valves were done while the manifold was off yes ... misunderstanding there sorry

Take it logically. Get a new expansion tank cap, an OEM spec one(flat black with brass fittings inside)
Air in the system tends to create a rising tank level rather than bubbling.
Boiling is usually associated with a failed pressure cap. The cap maintains a +1 bar pressure in the system, this raises the boiling point of the coolant.
If the coolant is boiling it's likely that the pressure is not being maintained, so try the pressure cap first.

ive taken a video of it boiling but i am struggling to upload it ... i will order a new cap tomorrow and try that ... working silly hours but got thursday off so al be at it again then ... i think its boiling my head never mind the car ... i should have left it to the scrap yard instead of doing a rescue lol