coolant problems...

[L-VrCalais]

hi guys

my vr seems to be forcing coolant out through the overflow hose when I turn it off, so what does this mean? blown head gasket? but there is no water in the oil and the raditor is like a month old and thermosat about 8 months old. So could it be the radiator cap?

[MR.HG]

Try taking the radiator cap off after it cools down and just have a sniff, sometimes the head gasket blows and allows carbon dioxide into the cooling system and produces a mild odor that is different to the heated coolant odor, this in-turn causes the radiator to pressurize causing coolant to be forced into the overflow. This particular breach of the gasket does not nec mean you will get water into your oil vice versa.
Did you recently flush? if so you may not have bled properly or there could even be a pocket/blockage in your radiator.
does it run hot or heat up when idling at lights? maybe the high speed is gone from your thermos.
cooling is a bitch but very important, id get that looked at asap.

yay first post hope this helps

[hako]

I'd say it definitely is not a head gasket as that will only cause coolant to be ejected whilst the engine is running, and yours occurs when it is just switched off, which indicates 'heat soak' - a weak/bad pressure cap is not keeping your cooling system pressurised and allowing it to boil at a lower temperature. When you switch a hot engine off, the waterpump is no longer circulating the coolant, so the heat from the engine causes the coolant to heat up rapidly (heat soak) - this should normally be OK with a good pressure cap keeping pressure at a max of 1.35Kpa and boiling point of approx 125de3g C, but if the cap is bad and not pressurising the system there will be zero pressure and the coolant will boil at 100deg C causing it to eject out the overflow tank.
So hopefully the fix is less than $10. Good Luck.

[L-VrCalais]

Yea na I didnt flush it completely, i didnt take the therostat of and run water thru the block if thats wat u mean. No it doesnt heat up i had that problem but i changed the temp sensor and sender and now the hottest she gets its just over half but the fans kick in straight away. Just went and got a radiator cap, drove it around got her nice and warm, stopped at home and she was NOT spitting the water so yea wat do you guys reckon? BTW Thanks guys for ur help greatly appreciated.

[zskinner]

hey mate, any chance does the coolant resorvoir level sit right on half-way between maximum and minimum mark? if so this is completely normal on the buick engines. if you fill it up to the maximum mark it will keep spitting coolant out until its half-way between. but if it goes below the minimum mark and still keeps spitting it out than theres a problem

[hako]

Nice easy fix!

[L-VrCalais]

So I dont understand how a radiator cap can do that to ur car lol