8 replies to this topic

[lefty]

Hi all.

On my 97 mpi, the radiator fan seems to love it's job too much! When engine gets warm the fan starts as expected, but won't stop again. I've even sat with it ticking over and watched the temp gauge go from 'normal' to cold and the fan just keeps on running.
If i switch the engine off, the fan runs briefly and then stops. Any suggestions?

Cheers

[Szolders]

There is temperature sensor in thermostat housing. I unscrew it, clean it and get it back, it help a little. When i decide to start restoration, i took whole eletric out of car and i clean whole cooling system. When refitting i spray every connector with wd40 and now i runs as good as new. (sorry for language mistakes)

[Surfbluegarage]

the ntc sensor that is in the thermostat housing is the one that controls the fan switch and the tempreture gauge so if the gauge is working correctly then there is something else amiss. id replace the sensor with a new one (not expensive) and go from there.. we have had to plug some mpis in to turn the fan off before although i wasnt entirly sure that the ecu has anything to do with the fan control but works.

[lefty]

Ok thanks very much. I'll check it out and see what's cooking.

[evansisgreat]

It's actually not to common for the sensor to fail, but this is a very common problem. The usual culprit is the connector that attaches to the coolant temp sensor. In fact there was a memo put out by rover at one point. Mini spares sells the replacement loom which cured the problem in my MPI. A little bit of soldering and it should be good.
When the ecu can't determine the temperature it runs in a 'safe mode' with the fan constantly running and a rich mixture.

Edited by evansisgreat, 20 June 2012 - 07:20 PM.

[Jake Didsbury]

Yeah they were a regular problem on the mpi, I read the rover report on it, it can also be caused buy the wires chaffing on the engine which is what the above comment is talking about I think. Also the actual sensor too, which has already been mentioned.

What happens is the sensor sends the wrong information to the engine, telling the engine its running hot, so the ecu richen's the mixture up to cool it down and also shoves the fan on, mine did it, but funnily enough I had a vac leak and i replaced the vac pipe from the servo and the fan hasnt been on since then, I did once hear air leak can cause it too so worth checking that aswell

Edited by Jake Didsbury, 20 June 2012 - 07:51 PM.

[lefty]

Excellent, thanks people. I love this site! :)

[lefty]

^{Well things are back to normal now. The only thing i did was to disconnect the plug from the temp sensor, gave the terminals a quick brush up and put it on again - hey presto the fan is behaving itself again. Lovely jubbly!}

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Could it be a relay? i had this problem recently on my minispares thermostatic fan as it never kicked in. Could be as simple as this.