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MG MGF Technical - Radiator Fan Not Working

Just back from 2 weeks in France - and have had problems with the radiater fan not working.

It was only a problem in traffic and switching the heater on full blast kept the water temperature under control.

Is it the thermostat thats not working? If so, is it easy to replace - does it require the coolant to be drained?

Thanks
Paul
P9 VLS
Paul

Hi Paul,

Or could be the engine temp sensor, which is easy to replace (no coolant drain - just a little loss as you swap them over) and costs less than £20. Certainly worth a try.

Dave
Dave

Paul - Or more likely it is just the sensor electrical contacts corroding, as mine has been doing for the last 4 years now. Just lift the back of the hood and take the engine cover off. The brown connector on the front of the engine on the left side is the one you want. Squeeze the wire clip and slide the connector off. Either make and break the connection a few times to clean up the contacts or spray some contact cleaner (preferred) around. Refit and the jobs done.

Takes me about 30 minutes these days. 28 minutes to do all the hood and engine cover removing/replacing and 2 minutes to do the connector. I do it about once every 6 months or so.

Dieter or Rob have photos of all this somewhere. No doubt the links will appear shortly.

HTH. Alan
Alan

I seem to have a similiar problem with overheating when held up in traffic particularly after a long run. The other day steam was coming out of the small tank at the back through the hole on the top of the cap.I can't hear the fan so maybe this is the problem...I've got it booked in at the Mgr dealers. The big worry I thought was that the temp gauge did not move and gave no warning. Is that right????
malcolm

Malcom, the header tank cap sucks, it costs little to replace and a failure would not cause the temp to rise. A faulty fan (for whatever reason) would cause the temp to rise.
Other than that, make sure the water is kept topped up (to the seam halfway up the tank, no higher)
Will Munns

Paul
I had the same problem. In my case the ECU was faulty, and had to be changed (dealer verified all the otehr points mentioend above and found no fault). Changing the ECU did it, except that it cost a packet (about 200 pounds for the part, if I remember correctly). I read somwhere later on that 50% of all ECUs diagnosed as defective just needed the contact points (on the ECU) to be cleaned... If only I had know at the time.

Anthony
Anthony

I tryed cleaning the temp sensor contacts, but that didn't work - they didn't look corroded anyway.

So I've changed the sensor - and the fan now works!!!! Well chuffed, thanks for the info Dave. The sensor cost £11.70 snd the parts man at Startins in Worcester says they sell loads of them.....

A fairly easy job - but make sure you change the right brown sensor, there are two identical brown sensors, one is a lot more visable than the other and is an oil temp sensor. The water temp sensor is much more hidden on the opposite side of the engine to the expansion tank. Oh, and I got the thread twisted when putting in the new sensor so I lost 3 pints of coolant (thankfully I was able to keep plenty of water in the expansion tank) while I mucked about.

Anthony, my propblem is a repeat of a similar issue 2 years ago. At that time my ECU was replaced. I'm wondering now whether it needed to be.

Paul
P9 VLS
Paul

Another case of sensor failure... hey, at least it is a cheap fix!

For those who want more info on replacing the temp sensor, see http://www.mgf.ultimatemg.com/hgf_diagnosis.htm
Rob Bell

Paul,

Glad it turned out to be simple and cheap. A faulty sensor seems to be quite versatile in the symptoms it can produce. In my case the radiator fan came on too often and eventually the idling was affected, running at about 1200 revs instead of the usual 900. One new sensor and all was back to normal.

Dave
Dave

Hi Paul

I had the same problem a couple of months ago - the dealer replaced the fan stating that it had seized and also that it was a common fault. However, there is little on the BBS which indicates it to be a common fault.

David
david stonehouse

<<the dealer replaced the fan stating that it had seized and also that it was a common fault>>

I always ask for the old component back in these cases. It gives me proof that they actually changed it and that it was faulty. It also gives me something to muck about with in investigating faults.

Bruce
Bruce Caldwell

Malcolm, London

I have exactly the same problem -what was it in the end on yours?

Colin
Colin Bell

Colin

The car goes in tomorrow so I'll let you know..

Malcolm
Malcolm

Colin

The MGR Dealer tested it until the steam came out and said yes the fan did not cut in and have replaced the fan switch( highly technical). So hopefully every thing is sorted. I haven't received the invoice yet but its only in the region of 20-40 pounds I think.

If I replace the header tank cap with a new one I think I've don every thing I can so far.

Good luck with urs Colin
malcolm

This thread was discussed between 26/08/2002 and 13/09/2002

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