[alien]

Hey guys - got a weird thing going on...

If i bring my engine up to temp, the coolant expands and pushes the excess into the overflow bottle as it should, however, on cooling it appears that it doesnt suck that coolant back into the radiator - so i end up with an overflow bottle that's overfilled (and its overflowed into the engine bay too) and a radiator that's a few hundred ml short on coolant.

Its not using any coolant - i can pour the overflow bottle back into the rad until its full to the brim and have just over half a bottle in the overflow every time.

My thoughts are that it could be the radiator cap leaking and hence not allowing the vacuum to suck the coolant back up, but surely i'd see evidence of coolant weeping out of the cap as well if that were the case?

Any other ideas what it could be?

[want33s]

I'd replace the cap. Either the spring is weak or the rubber gasket is squished or cracked.

[Scrawny]

Replace cap and check the hose between cap and overflow bottle has no cracks or holes

[shandy92]

Mate, i really hate to say this but that is exactly what mine was doing and my block was cracked and possibly my head. Start with the basics and replace the cap, get it pressure tested as it sucking in air in from somewhere. Then i would get a combustion gas test done. This will tell u if the engine is pressurising the cooling system from a crack in the head or the gasket.

[sideways]

Yeah, it's probably something simpler but it is what will happen when you've got a blown head gasket or cracked block/head. It pressurizes the cooling system and slowly pushes everything out into the overflow. My 1l did this when the head corroded right through into the combustion chamber, you'd just top the radiator up every now and then and empty the overflow.

Wash the coolant off the engine bay, it will eat your paint. There was no paint left anywhere near the overflow bottle on mine.

Now that you've had a heart attack, my LJ did the same thing when it had a dead radiator cap. Check the hose between the radiator and overflow. Make sure it's sealing well.

[alien]

Well the cap does seem very easy to twist on and off (no resistance) so i'm betting that's the culprit (it fucking better be!)

[shandy92]

Hey Aron, did that new cap fix the issue?

[alien]

Yeah been monitoring it... New rad cap fitted and it still did it.... then i "burped" the system via the temp sender on the thermostat - it shot a stream of about 2L of coolant about 2m in the air! hahaha Must have been a pretty big airlock in the system somewhere... Since doing that its been acting just fine so far as overflow goes... although the heater has been temperamental so i may also have a dodgy thermostat, will wait and see what happens there.

[shandy92]

ok no worries mate, hope you can get it sorted. If you can get a thermostat from suzuki let me know and ill give u a hand fitting it....if you need it (save you driving out to suzistore)

[alien]

Appreciate it mitch - i did one in my mazda (kinda), but didnt have the sealant shit to put between the surfaces, so put it back together without a thermostat and drove to the mechanics for them to seal it properly... lol