Been trawling around looking for some solid info on this. I suspect my head gasket (s) may be gone, but before I condemn it I want to get coolant running properly around the engine.

I gave my car to my brother as he blew the gearbox up on his Audi. A coolant hose on the LPG system cracked (poor quality hose) and he lost coolant and said the heater went cold. Don't know how long he ran it but he says he stopped quickly.

So..... I have the car back at my place (I trailered it home) and I have replaced the damaged hose. Problem is when I try to fill it the system pressurises the hoses and it overheats after about 5-10mins ticking over. Top of radiator is cold, large hose on right hand side of radiator (as you stand look into the engine bay) is stone cold. It just seems like the water is not getting around the engine. Is there a fail safe way of bleeding these things? Are there any special bleed screws? The head gaskets may well be gone, but I'd really like to make sure it's not just failure to circulate due to air, thermostat, water pump etc.

Any ideas?

could well be just an airlock (fingers crossed for you) but does sound more ominous tbh

there is a bleed screw on top of the expansion tank , open that and start the engine with the expansion tank cap off top up as it warms up or tank level falls


good luck

OK, I'll give that a go .....I'm not too confident though, like you said ......sounds ominous.

Can anyone recommend a good product for testing the coolant for exhaust gases?

My system has been completely empty due to my gearbox and engine oil coolers rupturing (internally) so my system had to be bled twice.

The trick is to keep going with the engine at idle and keep filling up, bleeding via the little tank.

The car should be level (or at least that how mine was done).

Just keep it going (takes some time, i.e. hours) and when the engine overheats, just let it cool down.

Maybe also replace the thermostat as it should open but it sounds like it doesn't.

The LPG conversion may have changed the cooling system such that it allows air to stay trapped in it. So you could look at high points in the cooling circuit and bleed at the high points. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

@marcoos -

You could also read this coolant tank bleed screw thread with pictures that might ( or might not be) of some assistance.

http://www.fullfatrr.com/forum/topic21436.html?highlight=ptfe

maybe your waterpump is kaput . . . which caused the other prob....................I stress the word MAYBE 5.0 supercharged autobiography
Gone-4.4 Vogue Lpg now unmapped
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