Overheating

Hi all, I have a 2003 mgtf, it will run all day with no faults at all but when I stop in traffic the temperature gauge goes up and the engine starts to overheat. Any ideas what can cause this?

First you need to determine that the fans are working.
Just idle until the temp rises, the fan (fans for A/C equiped cars) should kick in

Thanks, Yes both fans are working, the one in the front and the one in the intake.

You should check the radiator cooling fins aren’t blocked or damaged, probably best to pull it out of the car to do this and while you have it out reverse flush it.

I inherited a Ford Fairlane from my dad, it ran hot at idle,
I removed the radiator to find it with a loverly thick blanket of dog fur……. The car lived in the garage and had the dog’s beds right in front of where it parked, the car had one of those stupid thermal clutch fans, the clutch of which was partially seized and would obviously suck up the fur from the dog’s beds through the radiator! The hot running was cured when the radiator lost it’s fur coat. And I replaced that dumbarsed fan with thematically controlled electric fans.

Any signs of sludge in the radiator and you should flush the coolant pipes under the car while your at it.

Check the belt on the water pump.

The impeller of the water pump may also be corroded and pitted from cavitation, thereby not pumping well at low speeds.

Check your thermostat.

See how you go with that lot, report back your findings and we’ll go from there.

could be several reasons, for me it was a clogged toggle valve in the inlet manifold some time ago.

I should add that you need to bleed the cooling system at 3 points……… one on top of the radiator, another up near the heater box and one in the engine bay.
Check the archives here or your workshop manual for the procedure…….. you do have a Worksop manual! ……. No well you can download one from this site whilst your checking the archives.