hi guys, i have a duratec in my mgb. When i first got it running the rad was stone cold, i then drilled a small hole in the thermostat and it seemed to cure it and not the rad gets hot. Trouble is it now wont cool down again once its warmed up. Im running the standard setup, with the bypass hose above the thermostat going to the rear of the head. Do i need a bleed valve on the duratec? Im using the standard mg radiator which you fill at the top, i leave the cap off for a few minutes to bleed any air out but it doesnt seem to want to work.

Adam

squeezing the top and bottom hose my help bleed it.

I might be wrong but isn't the Duratec thermostat switched by the EcU? Or the by pass by ecu?

Not if you have swapped out the thermostat for a mechanical one

well today i emptied it and refilled it only at the thermostat outlet (above the main rad inlet). It now still overheats but if i rev it it cools down again. Ive squeezed the pipes, tried bleeding it, i even drilled a small hole in the top of the thermostat to try to get any air through it. The thermostat is a manual type from a fiesta st. The fiesta is a higher temp than the caterham one, should i try that one? at 40 pounds its an expensive thermostat if it doesnt work.

Adam

Stupid question...have you got it plumbed in the right way round?

Outlet is at the back of the head and goes to the top of the rad, stat is actually the inlet, bottom hose.

Whats the highest point of the system? Have you got a proper header tank? It will self bleed if you have it set up properly...

Basically the rad is an old fashioned one with a large tank at the top. The bottom of the rad goes to the thermostat housing, the small hose above it is blanked. I have the standard bypass hose fitted, from the back of the head it goes past over the exhaust and into the top of the rad.
Adam

are you sure your gauge is correct ?

i dont know how i can tell, im using a ford sensor with the emerald ecu, i was told it doesnt need calibrating.

put it in a mug of boiling water.......