Losing water on motorway trips. Help please!

[MattCutts]

Hi everyone, just after a little help. Whenever I drive my car and give it a little boost up the motorway over time my car shoots a lot of the coolant out of what I can only see is either the rad cap or expansion tank. Day to day driving around town it's perfect, it's just when I go on the motorway for around 30 minutes if not less. It's running at 1 bar of boost and the only thing I can think is maybe the head is lifting under long duration of boost or the turbo (being water cooled) is heating the coolant too much.

Is it possible to bypass the water lines to the turbo without it affecting the turbo?

Any advise would be greatly appreciated.

Thanks.

[TurboTobz]

Sounds like a gasket, get a test done on the coolant, can buy the kit yourself. Maybe worth trying another rad cap also.

[MattCutts]

I was thinking head gasket myself but I was hoping not, and as it doesn't do it unless I'm driving on motorway under longer duration of boost it was making me think the heads lifting.

Do you think a chemical head gasket test will show anything up even if it's not doing it driving day to day?

Thanks for the response

[TurboTobz]

Yeah it will, it'll detect traces of exhaust gases and turn the dye a different colour. Sounds like on boost it's pressurising the cooling system via a leak in the gasket.

[MattCutts]

I'll check it out tomorrow then and try a new rad cap for what it's worth. Thanks for the response mate

[TurboTobz]

No problemo!

[Adam-Gt-]

I had same issue with my last starlet turned out to be head gasket and I've just noticed that last night that my GT I've got now is doing the same thing

[Mimtu]

I had similar in mine a couple of years back. Never had a puddle under it when parked up but always loosing water when i'd driven it somewhere. I did the headgasket as a precaution as was having a couple of things done at the time but it turned out to be a tiny hole in a coolant pipe which leaked when the system was pressurised, so hence no puddles under the car when parked up. Took a bit to find the pipe that was split but once changed it was all sorted.

[MattCutts]

Mine had a 0.9 bar cap on it, so I've put a 1.1 bar cap on and it seems to be okay so far, so fingers crossed it just that. But I haven't been driving it as hard lately so I'll keep my eye on it and see.

[1991 starlet owner]

Yeah it'll be to do with the pressure in the system mate, it'll be the rap cap most probably (which is very important to get the correct one for your engine set up), you could have a little leak (mine was off the thermostat housing) but best way to check for head gasket gone is water in your oil! Check in your oil cap for a white murky solution and if not then jobs a gooden and it's less money!!!!

- also mate you could change your coolent and give the system a bleed.

Tom

Edited December 20, 2013 by 1991 starlet owner

[Zeldoz]

Yeah it'll be to do with the pressure in the system mate, it'll be the rap cap most probably (which is very important to get the correct one for your engine set up), you could have a little leak (mine was off the thermostat housing) but best way to check for head gasket gone is water in your oil! Check in your oil cap for a white murky solution and if not then jobs a gooden and it's less money!!!!

- also mate you could change your coolent and give the system a bleed.

Tom

That doesn't necessarily mean your HG is fine..