My thermostat is showing symptoms of being stuck open.  I would class myself as a novice when it comes to car DIY skills.  Is this a DIY job for a novice?  

 

Cheers

Sean

I would also like to know this, tho I'm sure it's a bit of a pain to do

I don't think that it's a realistic DIY job - dealers have it down as an approx 3 hour job. It involves taking the undertray off, draining coolant, removing airbox, engine cover, a load of hoses in front of the engine (which require a triple-square bit to undo I believe), the alternator belt and the alternator - all to get at the thermostat. Replace thermostat, then replace all parts that were removed, refill coolant, make sure system is bled and there are no leaks and hopefully problem solved.

 

Mine currently needs doing - the temperature gets to 90 around town but drops to around 75 on faster roads, looking on the climate control hidden menus, the needle on the gauge falls when the true coolant temp drops below around 74. I've also got a slow leak which means that the coolant level drops from maximum to minimum level in a month or so. When I get round to it, I'll get a garage to change the thermostat and look for evidence of where the leak is coming from. It will probably end up costing in the region of £200 to £250. 

When I replaced my thermostat recently on my Octavia VRS I found this video on YouTube really useful

 

https://www.youtube.com/watch?v=nZDMexvOlmU

 

It took me and a friend 4 to 5 hours to complete, having a good selection of tools, and the correct triple squares bits is a must.

 

I would definitely class the job for a more experienced person, remember if something goes wrong you're going to be stuck with a car going no where.

 

For the £200 to £400 you're going to have to pay, it will save you a lot of hassle.

 

Paul

 

 

 

 

Thanks guys. The video is really good but also makes me think its too much for me. I think I will get it sorted at the garage.....its pricey but will save me a days work plus the cost of the tools I don't have.

Quick update.  

I got the thermostat replaced at a local garage.  Cost £172 for parts & labour.  
Running perfectly now.  

Thanks for the advice.  

What were your symptoms? My temp gauge dropped whilst on the motorway today!

The symtoms I had last year -

 

It took a long time to warm up during the first run of the morning, about 6 miles, even when the outside airtemp was between 10 & 15 degrees.

 

The temp guage would only ever really get to just under 80 degrees when city driving, but the faster I drove the colder the engine got due to the

air flow through the radiator and over the engine (motorway driving the temp guage would vary between 65 to 80 degrees).

 

Changing the thermostat solved the problem and the car now warms up to 90 degrees within 2-3 miles of driving.

 

The wierd thing was that after I fixed the fault I had worse fuel economy?

 

Paul

Hmm...mine takes perhaps a little longer to warm up but once at 90 degrees if i drive at speed the temp drops to say 75-80 degrees then pops back to 90....my economy is poor at the moment (28mpg after a four hour drive to cornwall, mostly on the motorway!)

That sounds like thermostat - I had the same issues, got it changed and it now gets to 90 quicker and stays there rock steady! Haven't had a chance to do any long journeys yet to see if fuel economy has changed.

My symptoms were the same as Pauls but the temp dropped to 50-60 degrees when up to speed. Not been on a run to check fuel consumption since changing the thermostat.