P38A Coolant in cylinder head inlet passage

I replaced the head gaskets on my p38 4.0 Thor a few weeks back and everything was fine. A few days ago notice a coolant leak from one of the hoses, tightened the clamp and pressure tested at 14 psi it to make sure it was ok

I started her up and thought I heard a ‘whoosh’ noise from the engine as if something gave way, though I may have imagined that. Unfortunately there was suddenly dense white smoke coming from the exhaust.

I could see evidence of a coolant leak so pressure tested again for a few hours to find a small leak from water pump gasket. After that I dismantled again as I figured I must have got something wrong. When I removed the lower intake manifold the rear inlet ports on both banks are literally full of coolant as well as one of the front inlets.

Is it possible for a failure in the inlet manifold gasket to cause this or can it happen with a head gasket problem though it would have to be the same on both banks which u thought unlikely.

I did change to a head stud kit rather than stretch bolts and wonder if they’ve backed off somehow.

Any thoughts and advice greatly appreciated.

Sounds like you didn't get the lower manifold sealed correctly. Did you put the RTV in the notches at either end between the heads & block ? Also some of the rubber end seals need trimming to fit correctly & seal the valley gasket.

When I last did one of mine, I added a thin bead of hermatite sealer around the coolant ports just in case.

pwood999 said:

Sounds like you didn't get the lower manifold sealed correctly. Did you put the RTV in the notches at either end between the heads & block ? Also some of the rubber end seals need trimming to fit correctly & seal the valley gasket.

When I last did one of mine, I added a thin bead of hermatite sealer around the coolant ports just in case.

Click to expand...

Yes put on the RTV. Can you tell me where are the coolant ports are please? Cheers

The four middle larger ports each side are the inlets. Then the four at the corners (marked in red) are coolant passages between the left & right heads.

Thanks Pete. Much appreciated.