Suspected Busted Thermostat- Opinions Please.

[anonymous-user]

Hi guys.

So, for the last week I've noticed that my 1.4 MK6 Golf is taking an age to get to temperature on the guage, c.25 minutes if left to idle, and 10-15 minutes if driving and the cabin heaters are basically useless during that time as you'd expect.
I get that it's cold out at the moment which will have some effect, but not that dramatic.

I've narrowed it down to the thermostat being stuck open but I'm keen to hear opinions before I stump up for a replacement, as VW have quoted what seems a fairly obscene £536 for parts, labour and VAT (waiting for a quote from my local indy).

I've got my MOT on Saturday which I'll likely push back now.

Edit: being mechanical I can't diagnose it with VCDS but measuring block values are showing coolant temp at around 75c so even with the guage at 90c it's still running colder than I'd like, I've not graphed it from a cold start but will do at the weekend.

Edited by anonymous-user on Monday 29th October 17:42

Edited by anonymous-user on Tuesday 30th October 12:20

[Chiswickboy]

I'm more familiar with earlier Golfs but believe failing thermostats are not unusual on the Mk6. One of the problems with changing it is that the thermostat housing is plastic and prone to breaking so the dealer may have included the whole assembly in the quote, however I would wait for your indy to give you a price that is in the real world.

[anonymous-user]

Chiswickboy said:

I'm more familiar with earlier Golfs but believe failing thermostats are not unusual on the Mk6. One of the problems with changing it is that the thermostat housing is plastic and prone to breaking so the dealer may have included the whole assembly in the quote, however I would wait for your indy to give you a price that is in the real world.

The MK6's definitely seem to have an issue with the stats failing, usually open so as to not cause overheating.

As far as the stat housing, you can get an entire OEM stat and housing pack pre-assembled from Febi for £20, and the replacement is an hour's worth of work, so VW have basically quoted £516 for one hour's labour.

I've never used a dealer for work as I've always heard that their pricing is silly, but that is beyond silly, Halfords Autocentre by comparison have quoted £93, which I assume is £23 parts and £70PH labor, my Indie hasn't come back to me yet but I'm assuming it's be about the same, maybe a tenner cheaper.

[Oscar011]

9891Ian said:

Chiswickboy said:

I'm more familiar with earlier Golfs but believe failing thermostats are not unusual on the Mk6. One of the problems with changing it is that the thermostat housing is plastic and prone to breaking so the dealer may have included the whole assembly in the quote, however I would wait for your indy to give you a price that is in the real world.

The MK6's definitely seem to have an issue with the stats failing, usually open so as to not cause overheating.

As far as the stat housing, you can get an entire OEM stat and housing pack pre-assembled from Febi for £20, and the replacement is an hour's worth of work, so VW have basically quoted £516 for one hour's labour.

I've never used a dealer for work as I've always heard that their pricing is silly, but that is beyond silly, Halfords Autocentre by comparison have quoted £93, which I assume is £23 parts and £70PH labor, my Indie hasn't come back to me yet but I'm assuming it's be about the same, maybe a tenner cheaper.

Your local Indy like you said will be slightly cheaper than halfords. But please keep away from halfords. Such bad reputation. Wouldn’t trust them to pump my tires up tbh. The symptoms you are describing also sounds like your stat is open. Get your local Indy to do it.

[LuS1fer]

Different engine altogether but I had air in the coolant system that was hard to budge which affected the heater output. Ended up with the cap off pumping the hoses with my hand to shift air round.

[anonymous-user]

Oscar011 said:

Your local Indy like you said will be slightly cheaper than halfords. But please keep away from halfords. Such bad reputation. Wouldn’t trust them to pump my tires up tbh. The symptoms you are describing also sounds like your stat is open. Get your local Indy to do it.

My local indy is actually quoting £280, I'm going with him as I've used him for a lot of stuff and the work is good and has always reasonably priced, I'm more inclined to think that £280 is the 'right' price between VW's robbery and Halfords lowball, he's done me well this far, brakes, shocks etc.

As far as Halfords goes, I've used them in the past for an Aircon service, I had a leak and I knew it, and I was sure it was on the G65 sensor, took it in and they spent hours pressure testing and checking for leaks (whilst I was sat there) and they confirmed my theory and changed the part with one I'd supplied, £30, I've also used them for services and haven't been able to fault them.

This will be a shocker, I've also used my local Kwik Fit and they've been great, very professional, not touting for work that doesn't need doing, pointed me to others when they themselves couldn't help, I guess, as with anything in life, you can't tar them all with the same brush.

[anonymous-user]

LuS1fer said:

Different engine altogether but I had air in the coolant system that was hard to budge which affected the heater output. Ended up with the cap off pumping the hoses with my hand to shift air round.

That was also something I'd thought about, wondered if I had airlock, I'd debated starting her up with the expansion tank cap off and giving the rad hoses a squeeze to see but decided not to bother.

So, thanks for the input, you've motivated me!