Hello all,

I've been having a few problems with the temperature gauge over the past few months where it doesn't move up and sit happily at the middle temperature like it used to. Now for some long journeys it sits right at the bottom (cold end) of the temperature scale for the whole time.

I've noticed a few quirks about this problem that might help any diagnosis:

• Most of the time the gauge stays at the low end of the scale - especially when travelling fast (i.e. >50mph).
  
• Sometimes when stuck in traffic the temperature will reach its normal central point, but upon resuming ~40mph speeds the temp drops again to the bottom of the scale
  
• Once after a journey (30 min @ ~40mph) the temperature gauge didn't budge from the bottom. Upon stopping at home I opened the coolant reservoir (naughty I know) which let out the pressure. I went back in the car and the temp gauge was reading the correct middle temp!!
  

Ok, so having seen some of the other threads on related things (http://briskoda.net/fabia-i/temp-gauge/141185/) (http://briskoda.net/fabia-i/temp-gauge/138796/) it seems the problem is either thermostat or temp sensor issue.

With the information above can any give me any further information than this? It feels like everything is fine there is just a dodgy connection somewhere or perhaps it is just an old thermostat that is sticking and needs replacing?? I'm trying to avoid sending the car to the garage for something that I can fix myself.

Any help would be greatly appreciated,

Carl

Skoda Fabia 1.4 Classic 5dr 2002 (02) 55k miles

suspect temp sender unit and/or thermostat, both quite cheap parts , and probably easy to do as a DIY job

Sounds like the thermostat to me. I take it the level is ok?

If your water level stays ok, I would suspect the temp sensor located in the block.

HTH

This could be one of two very common faults. The way to replace the sensor is shown here. If you can see the thermostat spring when you have removed the old sensor, then the thermostat housing has failed. In this case, I would recommend getting the updated thermostat + housing from somewhere like Jorily or similar, as this has been modified from the Skoda design to prevent it happening again. It may be worth doing this pre-emptively anyway as it a bit of a time-bomb. A quick precis of the method is as follows:

1. Drain the coolant using the tap in the bottom corner of the radiator. Close the tap when it's empty!
   
2. Disconnect the hoses going into and out of the thermostat housing. If you have the uprated part, you will only have got one of the two parts that make up the thermostat housing. This is fine. Remove however much of the 'stat housing that applies to you...
   
3. Fit your new part, taking care that the O-rings sit correctly. If you have the uprated part (and have therefore split the two sections of the housing), you may find that the threads have stripped, in which case you can slip a bit of zip-tie into the hole, which will work in the same manner as a helicoil. IME, this should only be a problem if the thermostat's been replace several times (DAMHIKT).
   
4. Reconnect the hoses. If the spring clips are damaged, Jubilee clips will do.
   
5. Refill with coolant, switch on the engine, put the air con on cold, put the rear window heater and headlights on, and leave it running until the radiator fan kicks in. Switch off the engine, leave it to cool, and top up the coolant as necessary.
   
6. Enjoy your fixed car.
   

HTH

Thanks for the tips everyone, especially Ap0gee!

I was quite paranoid about the coolant level so I checked that all the time and there was no loss of coolant (I had a leaking head gasket on my 1st car - an R reg Fiat Punto).

I've ordered the temp sensor and the thermostat from Jorily so thanks for the tip about that website/shop.

I'll await their arrival and give you an update once I've tried fixing it (thanks for the guide on the link Ap0gee, I'm sure that will be useful).

Carl

Hope it works! If you still have your suspicions about the HG, then the tests on here are as good as any I've come across, and were used daily after one of the aforementioned 'stat replacements failed on my wife's car, which led to her dumping coolant all over the road... :eek:

Hey,

So I finally got round to changing both parts (sensor and thermostat) and it was a complete success.

Thanks for all your help, you definitely saved me a few quid. The thermostat was broken, you could see the spring had half broken away from its clip, I guess this was causing the problem. Apogee the document you sent the link for to replace the sensor was great, very useful.

Here are a few pics of the broken thermostat feel free to use them in your document if you wish:

Thanks again,

Carl