Hi all

 

My 2003 VRS is taking ages to warm up! It's been sat for 18 months and is now back on daily duties, I drive it 13 miles to work. It does eventually get up to temperature if I drive at higher speeds but the moment I slow down the temp starts dropping off and if I turn the heating on it drops to about 70 degrees. My MPG is down massively too, I'm thinking it's the thermostat but I thought I would check as the ex VAG guy at work reckons it is the gauge or the CTS. Anyone else experienced this?

We recently changed the cambelt, waterpump and coolant but I can't imagine it being an airlock as we ran it up with no cap on for a bit and revved it etc before putting the cap on.

Cts is easy to change and a genuine one off eBay should cost around £15

These are typical symptoms of thermostat failure - probably stuck after being stood for a long time.

 

Changing thermostat and coolant temperature sensor and both cheap an easy jobs - I'd do both whilst you are at it. 

 

Edited 15 December, 20196 yr by bigjohn

Sounds like open thermostat to me. 

My money would be on the thermostat too. I’ve just changed mine due to never getting warm. When I took my old thermostat out I found a small piece of the plastic housing had snapped off and got caught in the thermostat, stopping it from closing fully. From what I understand, a genuine VAG one is the way to go. Cheap replacements from euros etc don’t work properly and you’ll just end up doing the job twice.

I've also heard that myth about buying a genuine thermostat and fell for it as well, the genuine (expensive) one lasted 6 months and I had the same over cooling problem, brought a cheap one from carparts4less and its been working fine for the last 2 years.

9 minutes ago, duck said:

I've also heard that myth about buying a genuine thermostat and fell for it as well, the genuine (expensive) one lasted 6 months and I had the same over cooling problem, brought a cheap one from carparts4less and its been working fine for the last 2 years.

Funnily enough...

 

I replaced a temp sensor on a Mk4 Golf GTI with an OEM Febi one as it was the cheaper option and easier to do Vs. the thermostat.  It didn't work so I replaced the thermostat, it still didn't work.  After getting some help from my local indy specialist, it turns out the (brand new) OEM Febi temp sensor was faulty! 

Edited 19 December, 20196 yr by penguin17

Oh no we have contradicting info here then. The one I was looking at is a Circolli one from euro car parts which is £7.xx so I thought that's a great price but how long will it last. But if genuine ones aren't any good then I might just go for it. It says it opens at 87 degrees but the temperature is meant to be 90 degrees. Is that the correct temp to open at?

I replaced mine as well - I went genuine and it takes around 4 miles to heat up to normal temp - I didn't do the maths and never realised the genuine one gave issues ! Bad batch perhaps ?

 

It's about 27 euros here for the genuine and mine has been 100% since last April !