Losing water and high pressure in header tank

[coolamasta]

In me Astra Sport runabout (2.0l ecowreck) it seems to use a bit of water, IE need to top up every 100-150 miles, it doesn't appear to be leaking as in a physical leak though...

The heaters aren't very effective either IE kinda luke warm when engine is fully upto temp and when you undo the header tank cap there is some serious pressure in there, even if you leave it 1-2 days before opening it up there is still a lot of pressure!

The temp gauge reads normal on the dash, never goes over 100 etc...

I'm thinking it could just be a big arrrrse airlock but never really worked on a ecotec before so not entirely sure how to bleed them like the XE

Any bright ideas?

Oh and the headgasket was replaced on this by the previous owner over a year ago...

Cheers

[westy1]

sounds like head gasket

[Rob]

Few possibilities.

To bleed the system, turn the heaters on full power on hot and leave the top off the header tank. That should work out any airlocks.

The gasket might have been done but the head may not have been skimmed?

Had the same thing on my old cav 8v sri, replaced the gasket and it lasted for about 2 months.

[Tom Williams]

very common Rob on ecotec's and i would suggest with 95% certain its the head gasket.

nice easy job on an ecotec

[Mark T]

Same as my 3.0 at the moment.

Head gasket(s)

Least yours is only 1!!


Header tank will smell of exhaust fumes.

[coolamasta]

So you all think its deffo headgasket related? doh!!!!

Will that affect the heaters being crap though?

I will try bleeding it first and see what happens but I don't hold much faith in that solving it!

Will try sniffing the header tank as well next time I undo it to see if I can smell exhaust fumes!

What makes this happen then? just a bit of a gap on the headgasket by a waterway and it seeps through kinda thing? There is no condensation coming out the exhaust though, its all clean!

Ah crap just thought, its in for a MOT on Thursday, hope this wont effect emmissions!

[coolamasta]

Last night after writing the above, I went out and left the lid of the header tank off and ran it up to temp and you could hear the air bubble noise from the return pipe off the rad into the header tank!

Also the pipe from the thermostat to the rad when squeezing it you could feel bubbles of air going though it, anyway after doing that for a while the heaters have now got a bit hotter, but ive not really driven it anywhere yet to see if its using any more water!

One thing is for sure and thats its not physically leaking anywhere, totally dry under the car even under load and there is defiantly not any steam coming out the exhaust!

[Scoobler]

If you are using water and the system is presurising, its most likely to be the h/g. Water will seep into the bore when not in use, sometimes making it slightly harder to start and with a bit more than normal condensation when it does. However once running there is generally too much pressure from the cylinder to allow water in, hence no condensation but pressure in the header tank.

[coolamasta]

Cheers for that mate It does start perfectly, maybe I should see if theirs condensation when first starting it from cold? although wouldn't condensation in the exhaust come out then?!

Will be doing some more tests tonight anyway, in fact I might just drain it and start again with fresh water and antifreeze and see how it goes...

[chip]

Sounds like the headgasket to me too mate.

If you need some space to fix it, let me know

[coolamasta]

Can't believe it could be a H/G only had the pile for a month lol

Cheers chip, may be getting a call from me soon then lmao

Do you know anywhere that can skim heads cheap btw?

[coolamasta]

OOOOOOOOOOOOOOK Deffo looks like the H/G

Just drained whole car of the water which was a ****ty brown colour, not oil infested just a manky brown, refilled with new water and anti freeze, let run upto temp to get all air bubbles out, heaters were working the best they ever have! lmao

Took it for a hard-ish drive, came back, yup water pipes are hard as foook and theres lots of pressure when you undo the cap and this time I sniffed about by the cap when I undone it and it did smell of exhaust fumes

New gasket it is then

[Adam]

lol rather that than ur evo!

[Neo_Daz]

water escaping overnight ?

Had this on my old astra , turned out to be thermostat

It was loosing water through the top rad hose overnight after getting cold the pressure somehow pushed the water out , thermostat stopped it

Well it worked for me anyhoo

[chip]

Rob, about 30 quid where i get them done normally, depends on how much needs taking off.