What Temperature is to high?

[T-Cut]

Originally Posted by chrissyboy

- - - as long as the fan isnt running when engine is turned off then all should be ok with the cooling system. The fan is a 2 speed, replace the resistor. But if the fan isnt running on after turning engine off I would say the the fan is ok

The 1.8 fan will run at high speed if the coolant reaches 112C. It will also do this after stopping the hot engine if heat soak raises the head to 112C. It will run on for several minutes. All this is independent of the slow speed resistor.

The simplest way to check for resistor failure is of course the universal Demist button.

TC

[chrissyboy]

Originally Posted by T-Cut

The 1.8 fan will run at high speed if the coolant reaches 112C. It will also do this after stopping the hot engine if heat soak raises the head to 112C. It will run on for several minutes. All this is independent of the slow speed resistor.

The simplest way to check for resistor failure is of course the universal Demist button.

TC

which is what i said ,if all is ok the fan wont run on cause the head temp will not be 115 and over

[kaiser]

Originally Posted by Oli_BN1

I just had a service at Sterling Automotive (MG specialists), they told me that my fan is only kicking in at higher temperatures, and that it needs replacing.

This is the first I've heard about this. The fan definately works, and usually kicks in after about 45 min - hour of motorway driving, or if I'm stuck in slow moving traffic it starts whirring after about 20 minutes.

I've had my local mechanic look at it when he fitted a new radiator, but I stupidly gave it to him without any petrol in so he couldn't run it long enough to get the temperature up.

Any body got any thoughts on this?

Your fan should never come on during highway driving. At that speed the air from the ram effect should be able to keep things cool on by itself.

I would check the amount of coolant in the system.

[T-Cut]

Originally Posted by chrissyboy

which is what i said ,if all is ok the fan wont run on cause the head temp will not be 115 and over

I get the high speed over run when I stop the engine after a brisk run in summer. The slow speed system is fine. It depends on the engine's inertial heat load, not whether the slow speed system works.

TC

[kaiser]

High speed fan on on heat soak is normal.
I don't think it is the brisk run that does it.

Rather the brisk stop!

[chrissyboy]

Originally Posted by T-Cut

I get the high speed over run when I stop the engine after a brisk run in summer. The slow speed system is fine. It depends on the engine's inertial heat load, not whether the slow speed system works.

TC

mine used to do it all the time like yours until i changed the relay ,there is a little fan up near the wheel arch that runs when car is stopped not the main fan .id check that out if yours runs on

[kaiser]

A relay has no influence on fan operation, unless it doesn't work, in which case you fan won't come on.

However, the signal sent to the relay is the same, irrespective of the relay used.

So if yours stopped after replacing the relay, it is most likely because the new relay didn't work.

The fan under the front fender is for the autobox. If that comes on, it could be because the engine and box runs too hot, because the relay doesn't work.??

[T-Cut]

Originally Posted by chrissyboy

mine used to do it all the time like yours until i changed the relay ,there is a little fan up near the wheel arch that runs when car is stopped not the main fan .id check that out if yours runs on

Automatics have/had a fluid cooler under the wing. I don't have an automatic. The heat soak run-on is normal as Kaiser confirms. It's all covered in detail in the you know what disc -er, I mean the official Xpart manual



You're thinking about a stuck relay causing permanent key out running.

TC

[chrissyboy]

Originally Posted by T-Cut

Automatics have/had a fluid cooler under the wing. I don't have an automatic. The heat soak run-on is normal as Kaiser confirms. It's all covered in detail in the you know what disc -er, I mean the official Xpart manual



You're thinking about a stuck relay causing permanent key out running.

TC

normal ,as in the head is too hot so runs on to cool it...

[SD1too]

Originally Posted by kaiser

... the front fender ...

Remember what you were saying Kaiser about we British learning to speak our own language? Well, in the context of your posting it's a wheelarch. In English a fender is a cushioning device hung over a ship's side to protect it against impact.

Simon