v8 still overheating

hi checked all the normal things.
it may be the heads ,which i will take off.
but could it be somthing stupid like the the expansion cap.
this seems to lift when it gets up to temp.
just wanted to check before i strip her down.

many thanks

P38's aren't really my bag but before tearing into the engine and taking the heads off could I suggest you do a compression test.

As you have said, it is possible you have a duff pressure cap. Have you taken it off and looked at the condition inside the cap. If you have used Rad weld, Barrs or other quick fix leak preventer itis possible the cap is blocked and can't do its' job. Also if you have used something to stop leaks I would suggest you flush your cooling system thoroughly and get it all out of there. It does seem to cause more problems than it ultimately solves as it can not fix blown head gaskets or slipped liners.

Good luck.

i have to admit i'm a little concerned and curious how was the block tested for porus linner were the heads skimed? is the rad ok is the state ok and the pump if the block was tested and has failed so quick i would be concerened how it was tested.

have had this happen to me so i don't mess now every block is top hat linnered and in some cases i even add the irontite sealer if the customer requests it.

have you tryed a sealer to eliminate the block?

hi the block has top liners fitted, and was pressure tested.
but i did not get the heads pressure tested.
the rad in brand new , but i flused it any way before fitting.
i am coming down in favour of a cracked head.
i will take the themostat off and por in boiling water to see if it opens.

many thanks

many thanks

guinness said:

hi checked all the normal things.
it may be the heads ,which i will take off.
but could it be somthing stupid like the the expansion cap.
this seems to lift when it gets up to temp.
just wanted to check before i strip her down.

many thanks

Click to expand...

As you know, I've also had overheating problems on my rebuilt V8.

First it was the heater matrix, which was leaking and I bypassed it with a rubber hose.

Second it was the refurbished radiator which I had put into it and the water was flowing across the top of the radiator and down one side instead of through the whole thing, due to some blockages. I could tell because it overheated once after I took of the viscous fan I could hold my hand on the face of the radiator. Seemed like it should be hotter than that. Seemed to flow OK though. I had a radiator shop sort it.

Third, my viscous clutch is going out, I think. Works somewhat though.

Fourth I had a leak at the back of the engine. I think it was the valley gasket because the surface of the inlet manifold was not perfect, and I'm not sure I torqued down the bolts the two stages I was supposed to... maybe only the first torque levels. I took it apart, added some gasket sealer and torqued it down properly.

So I'm still putting it back together after sorting #4. Hope it's good after this.

Thanks,
Roger