So my Fabia MPI has been having some issue with cooling recently - generally running a little too cold, and taking a long time to heat up. The needle would always sit below the middle a little, and take 20 minutes to get there. I suspected a thermostat stuck open.

 

Ordered the housing assembly kit that includes the thermostat and sensor (£16, eBay), and fitted it today. Attached is a pic of the thermostat that came off, attached to the old housing. As you can see, the plastic lug holding it has broken and the thermostat has basically exploded open. This means that even when cold it was sending all the water round the radiator, keeping it cooler for longer than it should.

Thought this might be of interest to anyone seeing the same symptoms.

Incidentally, the new one is secured by a circlip instead of plastic tabs, which is a far better design...

 

Edited 21 November, 201510 yr by wiredsoftware

Yeah, that's a common failure.

Not surprised with that design!

Oddly, my gear change seems to be slicker now, wonder if that is because of it being hotter and the fluids being thinner...

Edited 22 November, 201510 yr by wiredsoftware

I replaced one for a friend at work recently on a 52-plate MPI,  I changed the whole housing plus thermostat plus temp sensor, but when I took apart the old one, I couldn't work out how it was supposed to function.  Thanks to your photo, I can see now that there was a 'clippy over' bit completely missing from his (and one of the lugs that holds it broken).  Wonder where that went?

 

This is everything that was within the housing:

 

Wow, that's completely the wrong thermostat, it's the same type as fitted in the 1.4 16v, my guess is that a garage removed the old thermostat and 'bodged' it by fitting a different type rather than replacing the broken housing as the OP correctly did.

Wow, that's completely the wrong thermostat, it's the same type as fitted in the 1.4 16v, my guess is that a garage removed the old thermostat and 'bodged' it by fitting a different type rather than replacing the broken housing as the OP correctly did.

Yep, good theory.

@wino that one looks nothing like either the one that I removed, or the upgraded replacement, wonder where it came from?!