306 overheating..why?!

[lethallizzy]

when in traffic, or stationary with the engine running my pug gets super dooper hot really quickly. what can cause this?
its fine when its moving cos i guess the air hitting it cools it but it worries me if i ever get into traffic!
i dont want a boiled pug! lol

[Ian_sUK]

Is the radiator fan kicking in?

[Old Merc]

I bet its not working.Common fault,the motor seizes up.

[hotmelt]

Radiator fan

[mybrainhurts]

French electricity doesn't work....

[Kitchski]

Which engine is it?

[lethallizzy]

I'm sure i hear the fan kick in, maybe it doesnt...hmmmmmm! is it expensive to fix/replace?
and its a 1.8 petrol. does that make a difference?

[hotmelt]

is it losing water? Maybe that small plastic part(crossing)

[Kitchski]

Fan should kick in just over half way. You'll either have a switch on the rad itself, which controls the fan or it'll be controlled by the ECU using signals from the coolant sensor, depending on the year.
If you've got a switch on the rad, bridge it to see if the fan cuts in. If it doesn't, hook a 12v supply directly to the fan to see if it works then. This will tell you if either the fan switch or fan itself is failing.
If the fan is cutting in, but it's still overheating you need to check you don't have air in the system. Check all around for leaks, including the black plastic coolant manifold on the back of the block above the O/S driveshaft. Any drips mean water is getting out and air may be getting in....not good.
If there are no leaks, the fan works etc, then your last ditch hope is a blocked coolant pipe. If they're all clear, start preparing to compression test the engine and look for well priced head gasket sets!

[StoatInACoat]

16v Pug engines ALWAYS heat up quickly in traffic. If yours sits at 70-75 normally and 90-95 in traffic you have nothing to worry about. If it starts going above 98 turn it off. Obviously check your water level.

Your car has a "low speed" fan (comes and at 89ish degrees from memory or when you out the aircon on if by some miracle you have working aircon) and a "high speed" that comes on at 98 degrees. To test these are not seized start the car, open the bonnet and pull the brown plug on the thermostat housing. Et voilà, two spinning fans. Hopefully.

To repeat, it will ALWAYS heat up fast. It DOES NOT mean you have an airlock or are loosing pressure, have a blown head gasket or anything else.

Edited by StoatInACoat on Wednesday 13th October 20:07

[Kitchski]

StoatInACoat said:

16v Pug engines ALWAYS heat up quickly in traffic. If yours sits at 70-75 normally and 90-95 in traffic you have nothing to worry about. If it starts going above 98 turn it off. Obviously check your water level.

Your car has a "low speed" fan (comes and at 89ish degrees from memory or when you out the aircon on if by some miracle you have working aircon) and a "high speed" that comes on at 98 degrees. To test these are not seized start the car, open the bonnet and pull the brown plug on the thermostat housing. Et voilà, two spinning fans. Hopefully.

To repeat, it will ALWAYS heat up fast. It DOES NOT mean you have an airlock or are loosing pressure, have a blown head gasket or anything else.

Edited by StoatInACoat on Wednesday 13th October 20:07

He's not saying it runs at 90-95, he's saying it gets very hot very quickly. 90-95 is normal operating temperature isn't it? Not 'super dooper hot', so you don't need to roll your eyes just yet
No it doesn't mean he has anything wrong at all, they're just suggesttions for things to look out for and hopefully eliminate.

Edited by Kitchski on Wednesday 13th October 22:55

[StoatInACoat]

Kitchski said:

StoatInACoat said:

16v Pug engines ALWAYS heat up quickly in traffic. If yours sits at 70-75 normally and 90-95 in traffic you have nothing to worry about. If it starts going above 98 turn it off. Obviously check your water level.

Your car has a "low speed" fan (comes and at 89ish degrees from memory or when you out the aircon on if by some miracle you have working aircon) and a "high speed" that comes on at 98 degrees. To test these are not seized start the car, open the bonnet and pull the brown plug on the thermostat housing. Et voilà, two spinning fans. Hopefully.

To repeat, it will ALWAYS heat up fast. It DOES NOT mean you have an airlock or are loosing pressure, have a blown head gasket or anything else.

Edited by StoatInACoat on Wednesday 13th October 20:07

He's not saying it runs at 90-95, he's saying it gets very hot very quickly. 90-95 is normal operating temperature isn't it? Not 'super dooper hot', so you don't need to roll your eyes just yet
No it doesn't mean he has anything wrong at all, they're just suggesttions for things to look out for and hopefully eliminate.

Edited by Kitchski on Wednesday 13th October 22:55

90-95 is not operating temp on a 1.8 16v. It should usually sit at arount 75.

For a 2.0 16v or a TU normal operating temp is around 92.

[Kitchski]

Not that it really matters, but aren't the 1.8 and the 2.0 the same engine in principle? Can't see why one would be so low and the other about average.

No replies from OP so guess problem has vanished.

[StoatInACoat]

Kitchski said:

Not that it really matters, but aren't the 1.8 and the 2.0 the same engine in principle? Can't see why one would be so low and the other about average.

No replies from OP so guess problem has vanished.

No. The 1.8 head is different, the block is ally, the cams and engine management are different, the transmission is different, etc. Not sure which of these influences engine temp but I presume the ally block disperses heat more quickly than the equivalent steel.

The 1.8 head makes an interesting upgrade for the 2.0 engine as there is far more material to machine and modify. The 1.8 engine is also considerably lighter than that in an XSI or a GTI-6 which in turn weigh about the same as the wrought iron mess found in a Dturbo.

[Kitchski]

I had no idea the XU7 was all alloy. You learn something everyday!

[lethallizzy]

StoatInACoat said:

Kitchski said:

StoatInACoat said:

16v Pug engines ALWAYS heat up quickly in traffic. If yours sits at 70-75 normally and 90-95 in traffic you have nothing to worry about. If it starts going above 98 turn it off. Obviously check your water level.

Your car has a "low speed" fan (comes and at 89ish degrees from memory or when you out the aircon on if by some miracle you have working aircon) and a "high speed" that comes on at 98 degrees. To test these are not seized start the car, open the bonnet and pull the brown plug on the thermostat housing. Et voilà, two spinning fans. Hopefully.

To repeat, it will ALWAYS heat up fast. It DOES NOT mean you have an airlock or are loosing pressure, have a blown head gasket or anything else.

Edited by StoatInACoat on Wednesday 13th October 20:07

He's not saying it runs at 90-95, he's saying it gets very hot very quickly. 90-95 is normal operating temperature isn't it? Not 'super dooper hot', so you don't need to roll your eyes just yet
No it doesn't mean he has anything wrong at all, they're just suggesttions for things to look out for and hopefully eliminate.

Edited by Kitchski on Wednesday 13th October 22:55

90-95 is not operating temp on a 1.8 16v. It should usually sit at arount 75.

For a 2.0 16v or a TU normal operating temp is around 92.

Ahhh sweet, thanks guys. you're right it normally runs about 70 and in traffic up to 90, which is what scares me!!
i'll keep a close watch on it in traffic now and see if it bobs above 95!

problem hasnt been solved, i've been on my travels away from compyooter!!!

cheers

[Simond S]

Does the 306 have a air release valve between the engine and the bulkhead. If so it's worth opening this to make sure you dont still have air trapped in the system.