Hi all. Matt from Essex here. Got a lovely P38 V8 and looking to get a 110 soft skin defender soon.

Can anyone give me some help please?

I have just done the head gaskets, ARP head studs. fitted new water pump, radiator and thermostat and I have a problem I can't figure out.

Engine heats up OK but pressure builds in the top coolant hoses. After checking the (new) thermostat it was hot on engine side and cold on the radiator side!
Rad also cool. I changed the thermostat for another new one and the same issue. I am stuck. Can't give it back to the wife like this so she is stuck with her bicycle until I can get it fixed.

I might be posting in the wrong place so apologies if I am and will gladly post in correct place if someone guides me. Thanks all

Please help

try the rr section im sure one of there butlers will have the answer

Thanks I think

Try putting the stat in a BOILING cup of water, does it open? if it does you are left with appx 3 options, 1. the pump is not pumping? do the heaters get hot with the fan on number 3 at least? if yes its not the poump
2 the engine is leaking compression gases into its water jackets or heads, did you pressure test them? is your block good (lots were not)
3 you have a blockage in the cooling system.....

Fastfish said:

Try putting the stat in a BOILING cup of water, does it open? if it does you are left with appx 3 options, 1. the pump is not pumping? do the heaters get hot with the fan on number 3 at least? if yes its not the poump
2 the engine is leaking compression gases into its water jackets or heads, did you pressure test them? is your block good (lots were not)
3 you have a blockage in the cooling system.....

Click to expand...

slipped liner by the sound of it or cracked block/head a hydrocarbon sniff test with an exhaust gas analyser will pick it up if they jump over opened header tank with engine running

Dont forget the possability of an air lock ,pop your top hose off and check/ fill it from there,