Coolant pressurising

V6. Has NEVER overheated but coolant forced out of expansion bottle while I was using car to jump start another. It was sat there reving at about 2500rpm for about 10 minutes when, whoosh, the water spewed out. Still didn't overheat! Garage tested it and said there was exhaust gas in the coolant...

So - have had new head gaskets, both heads pressure/crack tested (ok), new liners (whatever they are). That fixed the exhaust gas in coolant problem but was still pressurising up and bottom hose cold.

Then, had new thermostat, new water pump, new radiator and all new hoses.

Bottom hose getting hot but STILL getting bubbling sound and pressure in coolant, with cap in place. Take cap off and the water explodes out.

My garage doesn't know what to do... they say they have replaced everything that could cause the problem.

What the hell could it be?

Please help.
Mike

but have they replaced everything properly.....

repeat / multiple HGF is common on V6 hippos.

did they check the liner heights?
why did they replace the liners?
did they check flattness of the heads?
have they replaced the coolant bottle cap?
have they done a pressure check?

I understood that you cant replace the liners on a KV6. I think yo engine is knackered and yu need a noo one - preferably under warranty as yo garage have, most likely, ballsed this one up.

as Trewy sez - multiple HGF is so common, lots of dealers wont touch them or give a warranty if they do.

tried new expansion cap?

nice edit there MHM

yup - but a minute before yu posted .

The Mad Hat Man said:

yup - but a minute before yu posted .

Click to expand...

but minutes after i submitted due to ****ty connection!

'scuses

Thank you for the replies so far... I think...!

What is "multiple HGF"?

I think they replaced the liners saying that they "may as well" since they were in there anyway - ie. it would have been a gamble either way: they might be OK but they might need replacing! I don't know about "liner heights" - what is the significance of that?

I don't know about the "flatness of the heads" but, as I said, they were tested and said to be OK.

I had a new coolant bottle fitted about a year ago. Could the bottle cap be significant? If it WAS a bad fit could that cause the system to pressure up?

Pressure check - again I don't know, what is that?

It wasn't a Land Rover dealer - my local garage who I believe are good! - they do cars and HGVs.

The engine has always run sweetly, one careful lady owner... before me... and I have looked after it... it's never got low on oil, never overheated, I haven't thrashed its knackers off etc.

I am getting ready to jump in the bath with the electric fire... I am not very knowledgeable/mechanical so can anyone suggest anything else (in words suitable for a knumpty like me) and/or tell me what I should be asking the garage to double check etc.

Oh God help me...

HGF= Head gasket failure. I know of no one who has not had to replace head gasket on a petrol hippo. I've had four and replaced them all just in case. 400-500 quid if your lucky and as the guys have said some garages wont touch them as repeat failures are common. Thats if the lump is not scrap. Makes little difference if its been wrapped in cotton wool. Design fault.. do a search loads been written.

If you want to keep it sell your house and ya missus should be able to afford it then! Great motor when they run well...then again I know of makes and models that have more HGF problems than these.

Just thought you say you changed the expansion tank last year? did you replace the cap at the same time too. if so is it the correct cap for the tank used. Earlier hippos have a different tank and cap to later ones. just a thought

Does it pressurise the system and **** water out with the cap on ? It is meant to get to a certain pressure and all cars will 'explode water out' if you take the cap off when it is hot.