vx v6 loss of coolant so confused

[jbangr]

hey guys

i have a vx v6 and ive been getting an over heating problem. ive replaced get ready for it, radiator cap, radiator, thermostat, waterpump, countless amounts of coolant and time, its been pressure tested also. it seems like a fill it up to top bleed it, its good for a month or so then will start to over heat. im thinking that the vacum isnt working sucking the coolant back from the resivuor tank. i thought ill ask over here insted of speding 108 just to get it looked at by holden, f**k they are rip offs lol. thanks in advanced.

cheers
jay

[BlackVXGTS]

Loss of coolant can be caused by a leaking inlet manifold gasket.

[jbangr]

is there anything else could possibly be the problem just i might just get them to dtraight up change the inlet manifold gasket? how much you rkn it would cost mate?

[edals]

Have you replaced the Heater Tap also? They can always cause problems. Also is your heater core leaking at all? If both these are fine, and since you have replaced everything else my bet on a Inlet manifold gasket
And a inlet gasket costs quite a bit to replace. Gaskets are about $120 then there the hours of labour you will be charged. Took me about 6 hours todo one on the VR, but i was not exactly rushing either lol
Have you got any oil in you Coolant, or coolant in your Oil at all?

[Problemchild_87]

split hose ?

[Rhin0o8]

LIM gasket seems to be a problem here.
do you have a brown sludge in your overflow tank? means you have oil in your coolant - leaking Lower inlet manifold gasket
or a milky look to your oil? the reverse meaning coolant in your oil

check these

LIM gaskets should cost NO more than $400 take about 2 hours labor for someone who knows what they are doing

[Mattde]

ok to be completely honest i hardly know much about my engine etc but iv just recently bought a commodore from a mate second hand and have a similar problem.
I have been topping the radiator with water because it seems to be running out a hell of alot and getting really hot the lower it gets.
went to put a new thermostat in and realised the previous owner had taken it out altogether!
so the new thermostat works fine... not really sure what the issue could be..
my gf's dad (mechanic) mentioned something about it possibly being the water pump.
i know commodores run hotter and require specific coolant so im goin to top up on that tonight and see if it helps but i just want it fixed!!!
any ideas?
oh head gasket been replaced a few months ago so i damnwell hope its nothin to do with that

[Senna.In.The.Wet]

I had similar problem and it was a slight crack in the heater tap.

Replaced that then all good.

[Mattde]

thanks senna,
any rough idea of cost? and where exactly is this located (keeping in mind i aint no mechanic!) thank God for my dad!

[Mattde]

so jbangr im not sure if your problem is fixed yet but i got round to having a closer look last night and the heater tap was definately leaking.. the whole tray underneath it was covered in brown crap and the tap itself had basically deteriorated inside the tubes..
so goin to replace that prob tomorrow mornin and see how it goes.

[Room42]

Gaskets are $50. And a $15 tube of silicone for the corners.

Have you replaced the Heater Tap also? They can always cause problems. Also is your heater core leaking at all? If both these are fine, and since you have replaced everything else my bet on a Inlet manifold gasket
And a inlet gasket costs quite a bit to replace. Gaskets are about $120 then there the hours of labour you will be charged. Took me about 6 hours todo one on the VR, but i was not exactly rushing either lol
Have you got any oil in you Coolant, or coolant in your Oil at all?

[Room42]

Also mate if you have the wrong radiator cap the it wont suck the coolant back into the radiator from the recovery bottle when it cools down. It does take about a month for it to lose enough coolant to overheat. Check this.

[9C1pack]

Take it to a radiator specialist or mechanic and get them to pressure test it. Should not cost much, only takes a few minutes. You have spent loads on it and have not traced the problem, so it would seem the best otion.
The pressure tester has a radiator cap fitting on it, a hand pump (like a bike pump) and a pressure gauge.
They install it, just like putting the radiator cap on, then pump it up until its at the systems rated pressure, then watch for leaks or if the pressure drops off.

[Claudy]

Could also be the rear main plate leaking(it's at the back the motor in between the gearbox and the motor) u wouldn't be able to tell wether it's leaking unless u take gearbox or or its leaking a lot and ull se it drip after a drive

[Mattde]

PS. heater tap replaced = problem solved!
thanks for your help guys! (hope i didnt hijack this thread too much!)