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MG MGF Technical - Any idea?

Hello People,

I'm hoping someone can point me in the right direction with this problem. I have a 2000 plate MGF which has an issue with temperature. I have a 20 mile journey to work, if during the end of my journey I get stuck in traffic and have to drive either very slowly or come to a stand still I find the temp gauge starts to crawl up, this doesn't seem to happen if I've not done the 20 miles to or from work.

Any help with this would be greatly appreciated.

J Pondexter

Could be a 2 or 3 of things:-

Airlock in system!

Radiator fins corroded and not allowing sufficient airflow!

Faulty sensor for the radiator fan.

All are known problems the first being the simplest to cure - but remember there are three bleed points on the cooling system and they must all be bled.

The second obviously means a new radiator.

The third can be checked by letting the engine run for a while - normally about 20 minutes - whilst stationary and check the front fan comes on - DON'T confuse it with the engine bay fan - the front fan can not always be heard whilst in the car and you need to get out and go round to the front and listen!

BUT do try and get the car checked be a proficient mechanic - that is proficient with the *F* and the *K* Series engine.

A temporary 'cure' is to make sure the heater is on full heat as this will give extra cooling for the system and the other is to make sure that you keep the revs up.
Ted Newman

I would suggest to forget the other 2 and concentrate on the fan not starting. The symptoms you describe are classical.

As Ted notes the fan you are looking to start is the one in the front that cools the radiator when stuck in traffic! Which kind of answers your question by its descripton.

I am not sure where the switch is mounted on the MGF for ths fan or where the fuse is for it. But I am sure someone will be able to answer that question.

However the fuse should be either in the front fuse box or the fuse box above the drivers knees. Both are well marked and it should be obvious
Robert (Bob) Midget Turbo

If the fan is a little sticky on start up, then it will blow the 15amp fuse. The common fix is to replace it with 20amp.
Geoff F.
Geoff Farthing

I have a ScanGage fitted in my 2001 Steptronic and it is interesting to see how the coolent temp goes up and down according to driving conditions, heater-on heater-off etc. Temp soon rises to 105C when the cooling fan kicks-in when stuck in slow moving traffic, then you can watch the temp fall. When all this is happening the the normal temp gauge is just stationary just below the mid-point as is usual. I also have a by-pass PRT thermostat to help make the system more stable. It as also interesting to see the inlet air-temp again going up and down as the throttle is opened and closed, again my air cleaner is modified to pick-up cooler air by the LH side grill. If you want to get paranoid about what is going on in your engine get a ScanGage, after a time you understand this normal activity in the engine - it is good tool if you like experimenting.

A J Duthie

Check fuse 6 under the bonnet - upgrade to 20A. To prove the rad fan works, remove the connector from the brown temperature sensor on the LHS of the block elbow. It defaults to switching the fan on if o/c or faulty.

A J Duthie, were can you get a ScanGage from
AR Cayzer

The same sensor is used for the ECU and the fan - it is the brown sensor as described. If the sensor or wiring is faulty then the ECU will default to running the fan AND assuming that the engine needs a rich fuel mix and extra air (same effect as a choke in older cars). So if the sensor is faulty then expect to also see that the revs drop only to about 1100 rather than 900 when hot idling.

Sounds like a stuck fan or blown fuse to be
Will Munns

Try where you will find details and Worldwide Suppliers.
NB. Note the correct spelling.
Geoff F
Geoff Farthing

Anyone thought of a sticky thermostat? As it could be opening up when the waterflow is better i.e a decent run, then all the time it is hot all would be fine, it is just that I would have though a fan problem would have happened even after a twenty mile run?
aj harris

After 5 weeks, Jeff has not come back so presumably the problem is solved,
How ???
Geoff F.
Geoff Farthing

This thread was discussed between 04/10/2009 and 11/11/2009

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