overheating

[tricky]

hello surfers ! i have a problem with my LN130 i have had the complete head replaced about 7months ago ! about 3months ago straight after topping the coolant level up it overheated ! i let it cool down and of we went without a problem! i topped the coolant up at the weekend and the first run out afterwards it happened again ! it seems to only do it when ive topped up the coolant ! and i only top it up to the propper level .(half way up the header ) . any help would be muchly appreciated as its driving me nuts ! ive started to think its an air lock

[Koi]

hello surfers ! i have a problem with my LN130 i have had the complete head replaced about 7months ago ! about 3months ago straight after topping the coolant level up it overheated ! i let it cool down and of we went without a problem! i topped the coolant up at the weekend and the first run out afterwards it happened again ! it seems to only do it when ive topped up the coolant ! and i only top it up to the propper level .(half way up the header ) . any help would be muchly appreciated as its driving me nuts ! ive started to think its an air lock

First off your not topping anything up, should fill system via the rad cap not the expansion bottle.
Take off rad cap, open both heaters to hot setting, top up with coolant as required. Start engine and let idle for a minute giving a good couple of blips on the loud pedal. Switch off and top as required, repeat this a few times until no more coolant is required.
Take for a run check both heaters get hot, switch off allow to cool and check level again. Just check it over the next couple of days to make sure no more air locks move.
Expansion bottle only ever holds a few inches of water and is as its called an expansion bottle. As the coolant gets hot it expands, rad cap allows it to expand in to the expansion bottle, as engine cools its sucked back in to the engine.
If you fill the expansion bottle up all that happens is that as the coolant expands in to the bottle and then over flows because theres to much in there already.
Once you have done the above and it wont take any more coolant then that should be it. If after this it still needs topping up then you need to look else where for coolant loss, also check hose to expansion bottle is sound. Any holes in it and it won't allow coolant to be sucked back in to the engine.

[tricky]

thanks Nigel & Julie i will try that ! I've had it to the garage and had a pressure test done today on the cooling system, if it went from being blue to green there was exhaust gases in the cooling system but it he said it was fine , but the problem is still there,i think the only solution is to take the head of and have a look! its a shame because till this happened i really loved the car and it served every purpose i needed and is great fun off-road which i do alot when possible . Thanks Again Tricky

[marky]

I'D check your waterpump if its not rotating you'll overheat.

[Koi]

thanks Nigel & Julie i will try that ! I've had it to the garage and had a pressure test done today on the cooling system, if it went from being blue to green there was exhaust gases in the cooling system but it he said it was fine , but the problem is still there,i think the only solution is to take the head of and have a look! its a shame because till this happened i really loved the car and it served every purpose i needed and is great fun off-road which i do alot when possible . Thanks Again Tricky

would also check things like viscous fan, dodgy rad cap/stat.

[MikeSurf]

I was overheating when I stopped. I found the rear heater matrix was leaking. when you get hot the water in the cooling system isnt under presure any more so boils quicker.

Hope this helps.