Thermostat gone?

[bjh345]

On a couple of cold days I have been driving the corsa, and when I put the heaters on, no warm air comes out, and the engine just overheats.

The first couple of times it did this, I pulled over, switched the engine off for a few minutes, then restarted the car.
The temperature needle then dropped from 100ish way down to the other end of the scale, to 85-90°C, then got to normal temp. and was fine for the rest of the journey.

The other day, the same thing happened, so i pulled over, but the usual "fix" didnt work- luckily i was pretty close to home, so I was able to get back without it overheating too badly again (ie, getting above 100°C)

I started the engine whilst it was parked up and got it to get it warm again, the fan kicked in when it got too warm and it sill overheated, the fan not doing anything.

This all happened at temperatures about 0 to -4°, but there is antifreeze in it, so would temperature be an issue?

Normally the engine runs at 95°, maybe going a bit higher in traffic jams.
I have checked the oil, it is a golden colour, so I assume the head gasket is okay

Its a 1997 1.0l corsa merit with 65,000 miles on it, MOT'd at the end of October, and has had the timing chain replaced


Is this the stat that has gone, or something else?

any help would be appreciated

cheers

[Corsa84]

Sounds like the engine overheated because coolant has been lost, probably due to one of the following:-

1) External leak in cooling system (leaking rubber hose, loose clip, damaged radiator, leaking heater matrix) - most likely to be one of these.

2) Internal leak (head gasket failure, crack in cylinder head or engine block) - much less likely, but more expensive.

[bjh345]

Well I have had the car since october, and it hasn't needed any fluids topping up, so I don't think anything would be leaking.

I'm just wondering why it hasn't done this every time I drive it, instead of 3 times in 3 weeks, making me think maybe the thermostat is a bit faulty, not letting coolant round the engine?

[LesterPiglet1]

Sounds like a blockage of some sort. Try the thermostat first, and give the engine a reverse flush with a garden hose.

[bjh345]

Thanks, will try it tomorrow if it warms up a bit

[LesterPiglet1]

Saying that my hose is frozen.

[plexo]

my car is the complete opposite i cant get her to heat up its freezin in my damn car, warm air does come out of the heaters but its not warm enough lol

my temp gauge doesnt hit past 90C

[bjh345]

my car is the complete opposite i cant get her to heat up its freezin in my damn car, warm air does come out of the heaters but its not warm enough lol

my temp gauge doesnt hit past 90C

Could that be the Thermostat stuck open, so coolant is going round the engine as soon as you start it?

[LesterPiglet1]

Sounds like thermo to me bjh.

[plexo]

sorry to sort of go out of line from the thread but where is the thermostat, i take it its just like a sensor and could maybe be cleaned out?

recently had steel seal ran through her that might have made it stick open ?

[LesterPiglet1]

Sounds like thermo to me bjh.

Sorry this reply was for plexo.

[LesterPiglet1]

The thermostat is attached to the head. It is a mechanical valve not a sensor. You should be able to spot it easily as there is a coolant hose attached to it.

[plexo]

il have a wee look when its not below freezing temperatures lol the coldness at the moment is insane ..

running with it stuck open shouldnt do any harm though? just drink more petrol since icv will always be open trying to heat the car up?

[LesterPiglet1]

Worst it will do is freeze your toes.

[mcue23]

ARE BOTH PIPES ON THE RADIATOR HOT WHEN THE TEMP GOES UP OR DOSE THE PIPES PRESSUREISE?