Overheating problem....

First thing to check would be the electric fan or fan clutch depending on which the car has, then possibly the thermostat or even the water pump, but I'd expect any garage to be able to work this out. It depends whether the garage said they'd fix your overheating for 200 or whether they'd service and replace the rad for 200 (which they've done) Excess pressure in the system should be relieved automatically by the radiator cap so in an otherwise sound system one wouldn't expect the rad to burst. Sometimes if the rad cap has failed it can give the impression of overheating when in fact the car is fine.

Possible head gasket failure??

hes checked that and just serviced the car in full and said head gasket looks sound

a) Headgasket gone, cracked head, waterpump duff (usually impellor falling to bits), thermostat not opening, rad fan failed, airlock in system, defective radiator cap. Any or combination of those. b) Take it elsewhere. c) I doubt it however it's likely to have caused the headgasket to go if it overheated..

Take yourself down to your local motor factors. There's some stuff you can add to the expansion tank which turns yellow/orange in the presence of exhaust gases in the water which will indicate if your headgasket has blown or you've a cracked/warped head causing it. Start with that and let us know what you find.

great thanks anyone know what its called? cheers

If it loses no water "on a run" i.e. you start it, drive it around then stop and there's no water loss then it won't be the headgasket.

if it only overheats when stationary, then the trouble is likely to be a failed cooling fan.

Yep only overheats when in stationary or slow traffic, its not losing any water whatsoever! just spoke to the garage where i took it and he said its definatly not the head gasket

Im presuming if it does overheat the fan should be on ? anyway to test if its coming on when it should ? cheers

If the ignitions on yes. I can't remeber if the sunny runs the fan when the ignitions off. Oh & check the fans bolwing air towards the engine, not away from it.

ok i guess i found my problem!, the fans not running even when on tickover and temp gauge is high!

well, that was easy. check the fuse, if ok then bypass the switch and see if the fan runs, if it does then replace the switch, if it doesn't check wiring/fan itself

Mrcheerful

mmm not quite yet,llol Its not fan, i bypassed sensor in radiator and fan works fine, thought it might be sensor but bloke at garage says not neccaseraly, as if the hot water isnt going round system because of sludge then hot water wont get to sensor and inturn wont turn fan on, he is gonna remove thermostat tomorrow and run car and see what happens

That is true, but if the new rad is that blocked then you are in trouble. It is easy to see if the rad gets hot in the area of the switch. If the thermo was at fault then it would overheat when moving. Failed switches are common on all vehicles that have them. I don't understand why they did not spot this earlier.

Mrcheerful

Well THEY didnt spot it, id did! But the guy that worked on the car swears the fan was working when he was testing it!

Im presuming if i now replace the fan sensor in the radiator i have to drain the entire system ?

Because they're idiots.

No, release any coolant pressure and with the system cold, undo the switch and quickly wind the new one in, easy. If you have a bowl underneath then you can put back the cupful that may fall out.

You want a new garage, if the thermostats that buggered the radiator won't be hot at the bottom. & he's just changed the radiator. Anyway, if bypassing the switch stops it overheating then the rest of the cooling systems working.

cars been at the garage all day and theyve concluded its the water pump!, it isnt pumping water around the system like it should for whatever reason(corroded or stuck impeller ?) . new pump being fitted tomorrow........ case continues :)

If the water pumps buggered then it'll still overheat at speed & shorting the fan switch out won't stop it overheating when stationary.