Rover 3.9 v8 over heating.

[meathumper1]

Hello all, Ive got a range rover 3.9 which blew a head gasket, so i got the heads skimmed, they dident need doing as they were straight, but got them done just incase, changed the gaskets and put it all back together. Then to find i was getting exess pressure in the water system. So off come the heads again with all intentions of changing them. On looking in the engine bay at the block we noticed a mark (pitting) on the block on the left hand side, in between the water way and the cylinder. So after seeing this we then thought its not the heads its the block. So out come the block and that was skimmed to, also put in a new cam, timing gears & chain, lifters, bigend and main bearings Then all back together again. Once all together started it up and went for a drive and still exess pressure, so i bought a chemical test kit to test the coolant of cylinder gasses and sure enough gasses pressent. Now the last resort i suspect damaged liner so in went the Ironite, went for a drive today and i dont think its cracked it. But now im over heating. Eny ideas please? And no i dont want to scrap it, or burn it out.

[katanaman]

I take it Ironite is some kind of sealer? If it is then its unlikely to seal a cracked block as its compression your trying to stop and not coolant pressure. Anyway that aside it has possibly partly blocked up your radiator. It happens with stuff like radweld and the likes.

[meathumper1]

Yes its a caramic sealer for the later 4.0 serpintine engine which are well known for block problems, I think its solved the exess pressure problem, its just over heating now. If the rad has been blocked by it, that could be, it as the rad wasent to clever enyway. Thanks

[Ian Anderson]

Turn off the cockpit heater to force all the water through the rad

Sounds crazy bit it is such a low pressure required to move water through the heatr matrix that it takes the easy route and avoids the rad

Ian

[meathumper1]

I think ive cracked it, a new rad and it seems to be ok now.