over heating?

[ReeceH]

hmm.....

my let is overheating, but there is no oil in water or any signs of head gasket failure. heaters are always cold.
had a brand new water pump so cant be that, id ive just changed the heater matrix and still doing the same
i was thinking air lock? just want more opinions
any ideas?

[Adam]

Thermostat jammed shut? Does the whole rad get warm?

[ReeceH]

yeh the rad gets warm. took the insides out the thermostat so its constant flow

when i start driving after about 15 mins the temp will start gan up till about 100 then if i let it idle for a couple mins itll go back down to 90-95 then go up again when i set off again

[meritlover]

does it actually over heat/boil over or are you just going by the dash gauge?
do the hoses go rock hard after just a few mins of running? have you tried bleeding the cooling system properly. im sure there are a lot of things that can cause this but just because oil and water are not mixing doesnt mean that the cylinder head gasket hasnt been violated between the cylinder and the waterjacket.

[burgo]

when you say the heaters are always cold your not checking the center ones are you?? make sure you check the windscreen ones and if they are always cold then make sure you check the heater cables and flap are operating properly. if your heater s still always cold then you obviously have an air lock

[meritlover]

..or a blockage in your pipeage

[Welsh Dan]

Does it pressurise?

[R1CH]

When did it start over heating ? what was the temp at when running ok ?
Take it you've bled it thru the 'bleed screw' on the thermostat housing (or thru one of the sensors) ?

[ReeceH]

yeah the pieps go hard after about 15 mins of it running.
when you pour hot water into the heater matrix pipe the heaters go hot then.
its in a corsa by the way

ive just bought the car, been sitting in a mates drive for a couple month,sold it cheap coz he didnt know what was up with it


i let the water out the top rad hose and tryed filling from the bottom so it filled from the bottom upwards.just done this quick mind in a garage on way home from buying it.
didnt know where the bleed screw was so never tried that

id just like to add, my fan isnt working also.... lol

[meritlover]

mabe thats why its over heating if the fan is broken. unless it overheats whilst driving also.

start by getting a good bleed on the system and then take it from there.

[ReeceH]

gonna get me mata to come bleed it properly on the weekend and may try another rad, cant do no harm to try i suppose