Cooling system question

[mmac78]

Hi guys
Got a very noobie question for you all. Last week my Jimny overheated and looks like the thermostat has gone wrong. What I wanted to ask was, there is a coolant only bottle which the over flow pipe leads to from the top of the radiator. Yesterday it was at max level and today it was virtually empty. I thought this was just an overflow tank? Do I need to put coolant into it and does it feed the radiator when it needs it? Because when I've topped up coolant I've always made sure the coolant only tank was topped up also - or was I wrong doing this?

Hope you guys can shed some light for me.
Cheers all!

[twiss]

It should push water into the tank as the rad heats up, and then suck it back out (I think) as the rad cools down?

[Jordi]

^^^^ What he said.

It's the expansion tank. When the engine is hot it should be reasonably full, when the engine is cool it should be fairly empty.

[mmac78]

Thanks for the replies. Okay I've found it lost some coolant after a little drive today so topped up again maybe I shouldn't have topped it up at all.

[SherwoodNash]

^^^^ What he said.

It's the expansion tank. When the engine is hot it should be reasonably full, when the engine is cool it should be fairly empty.

To quote from my Owners Manual
"Inspection, with the engine cool, check the coolant level in the reservoir tank. The level should between the 'FULL' and 'LOW' marks. If level is below 'LOW' mark, replenish until the new coolant has reached the 'FULL' mark.
When there has been a large decrease in quantity of coolant, or when refilling has to be done frequently, it is possible that a leak may have occurred in the cooling system and should be investigated"


'Just checked mine and is up to full mark when cold, so a little too high, I'll be siphoning some out for more expansion room.

[mmac78]

Thanks for the info SherwoodNash, appreciate it!

[dan_2k_uk]

It should be full when cold. No need to remove any.

[zook123]

I still can't understand this system, I'm used to an expansion bottle which never moves, yet the Jimny is up and down like a whore's knickers!

[mmac78]

little update for you all, replaced the thermostat and the radiator cap to no avail. What is happening is, it's dumping its water out of the rad and into the expansion tank - and then its p***ing out of the overflow pipe of that on to the floor. Replaced the thermostat like I said and it still done it. Thought the rad cap might have lost it's strength in the spring so replaced that and it's doing it again.
looks like there's exhaust gasses pressurising in the system - so I can't really afford to throw money into it anymore to replace the head gasket so regrettably it's going to a new home.

maybe one day in the future i'll come back to another Suzuki

[SherwoodNash]

Oh that's too bad

Did you do a 'sniff' test to confirm 100% it's the head gasket?