overheating

hi. my dads got a 3.9v8 RR 93-k. its overheating i have replaced the thermostat and the rad but its still overheating can anyone help?

thanks craig

head gaskets/porous liner

if its chucking coolant out of the expansion tank then i'd suspect a porous liner

we have tried the head gasket and thats fine. we hoped it wasnt the liners but lookes like it its thanks

In my experience a porous block will give you 3 easily identifiable indications ...

The Top Hose will be rock hard - exhaust gases getting into the cooling system.

Bubbling / Hydrocarbons in the Coolant Bottle.

Poor starting when the engine is cold - water is pushed into the cylinder where the block is porous.

The 'Fire Ring' on the HG has a bigger diameter than the liner allowing combustion gas to travel down / water up the side of the liner.

The 'Top Hat Liners' eliminate this problem.