RRC V8 overheating

[meathumper]

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. :'(

[Range Rover Blues]

You've obvioulsy spent a lot of cash on it by now.  It's overheating, so assuming it's not an external cause then the most likely culprits are air locks and pressurisation.

If you suspect it's pressurising then I'd sugest a blow down tester, but these are £100 or thereabouts if you can't hire one, try E-Bay.

You've tried Irontight which tend to make me wonder if it's a cracked block, the reason cracked blocks cause probelms is that the liners can then slip, if the liners had slipped you would have noticed when it was in peices.

So, is it using water? is it blowing out of the header tank and are you sure it wasn't just an airlock (the V8 is hard to fill up with water).

[meathumper]

Hi thanks for reply, It was useing water when the gasket went the first time then after new gaskets in it was pressurising and blowing out the header tank, i first hoped it was air locks but after lots and lots of bleeding it would still pressurise after about 12 miles. Thats why i thought it was a crack as it was only doing it after 10-12 miles. Crack was opening just enough to let compression gasses through but not the other way round. I bought a combustion leak tester that is put on the rad and the fluid changes from blue to yellow if combustion gas is pressent and it was possitive

[Range Rover Blues]

So it's just a matterof where :-k

Did you use composite gaskets? on the heads.

I'm thinking that you might be best getting another engine, I know you've chucked piles of cash at this one but if there is ablockissue and IronTight hasn't done it then it's past saving.

[meathumper]

Yes composite gaskets from real steal. The irontite Has fixed the over pressuring problem but has give me a over heating problem now.

[300TDi Disco]

After i changed the thermostat in my V8 & put water back in the system, i had it overheating. So i pulled over and felt the water pipe leading to the thermostat and it felt solid (pressure). So i opened the expansion tank to find loads of air coming out (fast) & after that i have never had a problem (touch wood).

[Range Rover Blues]

Yes composite gaskets from real steal. The irontite Has fixed the over pressuring problem but has give me a over heating problem now.

Take the stat out, the irontite might have messed it up.

[meathumper]

That sounds like a simple air lock, wish mine was that easy. :(

[meathumper]

The stats working i think, as the heaters work.

[Range Rover Blues]

When the engine is cold and the stat is shut all the water goes to the heater, when the stat opens less water goes to the heater, however if the heater is working then I don't hink youhave any air locks in it.

Remove the stat for now, then at least you can say it isn't that for certain.

Have you got a decent fan and how good is the rad, it's just occured that irontite will block up a silted radiator.

[meathumper]

Well, In the begining after the first gasket change a fiend said he thinks its pressurising because its to hot. He thought this because the aircon fans where coming on and they do this for a back up if it gets to hot. So we changed the temp sender and still the same reading so we out ruled that.
 But yes the rad is crap got one on the way.
As for the viscous fan, my brothers got one that has jammed on so i tryed that one and i got further than i did with mine before it started to get worm.
 So it could be a combination of a bad rad not cooling good enough and a fan not blowing hard enough?

[Range Rover Blues]

Unless it's using water agin I'd want to be totally sure the cooling system was up to the job and it could be the irontite has just made the rad too bad.  If you've got a good one to try I'd suggest you do that before spending any more.

[meathumper]

Yeah, ive got a rad on its way, going to soak it in coca cola before fitting. Then see if it stops over heating. Im on going holiday on friday so its going to have to wait until im home. Thanks for help ill let you all know how i get on.

[buster uk]

i think once the rad has been changed ,and with my locked up fan on it should be ok.

[meathumper]

Hello to all, i think ive cracked it. new rad and its not over heating and i dont think its pressureising. Well i went for a drive and its cool as can be and no water getting spat out. So ive put a bottle of K-seal in to be sure. Thanks to all who helped and i hope i can go finaly and get it stuck in some mud.

[Range Rover Blues]

Magic :D

Leave the K-Seal in for good.