Ford Focus 1.6 TDCi - MOT Diesel Emissions

Honest John Back Room » Technical matters
View Threaded
Mon 9 Jun 2014 19:39
Ford Focus 1.6 TDCi - MOT Diesel Emissions - E-Chen

MOT due next week and I think the coolant thermostat has failed. The car has always taken a long time to warm up but now it only gets half way up the guage unless it sits in traffic just ticking over when it goes up to "normal" at the top of the guage.

If the engine does not get up to normal running temperature will this effect the emissions readings at the MOT?

Reply | Report as offensive | Link
Tue 10 Jun 2014 10:45
Ford Focus 1.6 TDCi - MOT Diesel Emissions - dieselnut

It's not likely to affect your emissions enough to fail. But all the time it's running cold it will be using more fuel.

The thermostat is a cheap part so will soon pay for itself in reduced fuel costs once replaced.

Reply | Report as offensive | Link
Tue 10 Jun 2014 12:09
Ford Focus 1.6 TDCi - MOT Diesel Emissions - MrEckerslikefromRamsbottom

The thermostat is integral with the housing, so you have to change the complete plastic body. Not a difficult job, but a lot of bits have to be removed for access.

Don't think of buying a second-hand one (there's a lot of 'em on e-Bay) because the gasket fails with age. The rubber gasket swells and pushes on the internal plastic wall, which is too thin (design error, or deliberate?) to take the pressure and eventually (after eight years on mine) breaks so that you get a coolant leak from the side of the housing.

Reply | Report as offensive | Link
Tue 10 Jun 2014 12:58
Ford Focus 1.6 TDCi - MOT Diesel Emissions - E-Chen

Thanks folks, your help is much appreciated. I'll get it sorted even though it probably won't affect the MOT.

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide