Temp Gauge.

[FLYING BANANA]

The Flying Banana has a problem. Start up and drive away perfectly ok then Fan switches on and runs constantly and temp gauge drops down to cold. No hot or cold air comes of the vents with the fan on. Car does not overheat and runs perfectly ok. Turn ignition off and fan stops straight away. Start up and the system operates properly. No water loss.
Could it be the thermostat? Airlock? Or a sensor playing up? Need to get it sorted as Banana is 'appearing' at MG 90 in 2 weeks time.

[rich17865]

Unplug the temp sensor, you will probably find the female pins.in the plug need closing back up. Because of.the routing ofbthe cables, pressure on the plug causes the pins to get too far apart and makes an intermittent connection.

See what happens after that :)

[Ratty]

I had that problem Bob I ended up changing the temp sensor

[chrissyboy]

does sound like engine coolant temp sensor car is thinking the engine is hot and asking for the fan to come on

[sworks]

I've seen the PRT cause this issue too, temp gauge drops down and goes back to normal once the ignition is cycled, can't remember if the fan kicked in though so maybe worth a look if the temp sender and connections are ok

[FLYING BANANA]

With the invaluable help of Ian , Redfive, the temp sensor plug has been taken off and cleaned. And so far after a good drive up and down dale Banana has behaved herself.
Because I rarely use the Air-con I noticed that when I put it on the revs would die away but then pick up. Thinking it might be the alternator Ian put me in touch with a local company, AMB-Vette co.ltd, who tested the alternator putting under load. Nothing wrong.

So many thanks to those that offered advice about the temp sensor and lots of thanks to my Very Good Mate Ian.:bowdown:

[stevestrat]

Because I rarely use the Air-con I noticed that when I put it on the revs would die away but then pick up. Thinking it might be the alternator Ian put me in touch with a local company, AMB-Vette co.ltd, who tested the alternator putting under load. Nothing wrong.That could be the stepper motor in the IACV Bob, it's supposed to adjust the revs according to the load on the engine. Needs to be tied up to a T4 for adjustment. Brian discovered mine had never been adjusted!

[rich17865]

With the invaluable help of Ian , Redfive, the temp sensor plug has been taken off and cleaned. And so far after a good drive up and down dale Banana has behaved herself.

Cleaned?? :shrug:

How bizarre, not seen that one before, what have you cleaned it with? Certainly would be helpful to other members if you shared what you did :) :bowdown:

[FLYING BANANA]

Cleaned?? :shrug:

How bizarre, not seen that one before, what have you cleaned it with? Certainly would be helpful to other members if you shared what you did :) :bowdown:
With the end of a screwdriver, scraped the pins.

[Ian G]

Cleaned?? :shrug:

How bizarre, not seen that one before, what have you cleaned it with? Certainly would be helpful to other members if you shared what you did :) :bowdown:
Hi Rich
Just a simple scrape and general clean up of the plug connections no idea if it's a permanent fix although it seems to have worked so far as the gauge sits steady but if not we will change the sensor and see if that helps, they are in stock at our local factors for £12.
Cheers Ian