Thermostat stuck open

[JoshJaggard]

Thermostat stuck open effects??

[shail]

I had mine replaced 2 weeks ago.

Symptoms:
Took quite awhile to get to 90 degrees
On cold days (around 2 degrees) temp would drop to 70 when driving at speed, along with drop in heater temp.  Would creep back up to 90 when in traffic.

[AJP]

I've noticed mine sometimes drops a tiny bit from 90, maybe only by 1mm or so at the tip of the needle, so indicating about 88 degrees or something.

It never drops any further, and for 95% of a journey it's bang on 90 once up to temp.

I take it this still indicates a dodgy thermostat?

[Bigjimknickers]

Looks like a common problem, mine chooses when to get to 90deg sometimes stays around 85-88, I've called SE Autoworks for a quote twice now & even went in there to see the fella & heard nothing back yet, I'm expecting it to be around £200 all in?

I'm hoping that replacing this will help improve the fuel economy? Like maybe it's overfueling thinking it's still cold?

[shail]

I've noticed mine sometimes drops a tiny bit from 90, maybe only by 1mm or so at the tip of the needle, so indicating about 88 degrees or something.

It never drops any further, and for 95% of a journey it's bang on 90 once up to temp.

I take it this still indicates a dodgy thermostat?

That's how mine was for over a year, just sat slightly below 90.  Then this winter, when we had a bit of a cold snap it started to get a lot worse all of a sudden. 

Its now spot on - sits dead on 90, and gets there a lot quicker than before. 

[AJP]

I've noticed mine sometimes drops a tiny bit from 90, maybe only by 1mm or so at the tip of the needle, so indicating about 88 degrees or something.

It never drops any further, and for 95% of a journey it's bang on 90 once up to temp.

I take it this still indicates a dodgy thermostat?

That's how mine was for over a year, just sat slightly below 90.  Then this winter, when we had a bit of a cold snap it started to get a lot worse all of a sudden. 

Its now spot on - sits dead on 90, and gets there a lot quicker than before.

Was that the main stat? And what sort of price are we talking for the work?

[JoshJaggard]

I've been quoted £140 all in

[JoshJaggard]

I had mine replaced 2 weeks ago.

Symptoms:
Took quite awhile to get to 90 degrees
On cold days (around 2 degrees) temp would drop to 70 when driving at speed, along with drop in heater temp.  Would creep back up to 90 when in traffic.

Any difference after having it done?
Mpg Etc?

[Bigjimknickers]

I've been quoted £140 all in

Where was that then?

[Red leader]

I've just had my main stat replaced, got the car 2 weeks ago and was getting only to about the quarter mark on temp gauge and about 17mpg. Now it takes 5-10 min to get to 90 degrees and mpg is up to about 25mpg around town. I'm going to do the 2 inline temp gauges as well soon and replace the left rear sticking caliper. So mpg should increase even more,hopefully.
Also paid £120 from an independent in Manchester.

[JoshJaggard]

I've been quoted £140 all in

Where was that then?

Just my local garage,
I would have guessed changing this may help the mpg a little? As it will more than likely run rich in fuel?

[SlapdingVW]

Recently had mine changed after it got stuck open. Who'd have thought it would be such a PITA job to change a thermostat   

Anyway as others have said the coolant takes a long while (>15 mins) to reach 90deg if it even gets there at all. Mine sat around the 70 degree mark whilst moving, then would creep up to just below 90 at a standstill before dropping down again. Also noticed a slightly lower mpg, although nothing too drastic... maybe 5mpg lower than normal.

I also had a couple of "fuel system too lean at idle" codes logged, however this may not have anything to do with it as my hpfp happened to break around the same time as my thermostat.

[JoshJaggard]

Recently had mine changed after it got stuck open. Who'd have thought it would be such a PITA job to change a thermostat   

Anyway as others have said the coolant takes a long while (>15 mins) to reach 90deg if it even gets there at all. Mine sat around the 70 degree mark whilst moving, then would creep up to just below 90 at a standstill before dropping down again. Also noticed a slightly lower mpg, although nothing too drastic... maybe 5mpg lower than normal.

I also had a couple of "fuel system too lean at idle" codes logged, however this may not have anything to do with it as my hpfp happened to break around the same time as my thermostat.

Yes, my mechanic quoted me 2 hours for this thermostat, crazy!
Mine will only get to 90 if town driving, or slower driving
When on main roads it can get as low as 65ish

[pudding]

From my logging days, I noticed that lambda control kicks in at 25 deg water temp, so it shouldn't over fuel for too long.

[Dan_FR]

Don't forget guys that indicated temp as displayed on the clocks does not correspond with the actual temp. The '90' on the clocks is anywhere from 75 degrees C to over 100 degrees C

So if you see ANY deviation from the 90, then your car is likely to be 15+ degrees away from ideal temperature. A fully functional thermostat should keep the actual temperature around the 91 mark + or - 3 degrees C, maybe a little more on occasion.

An indicated 70 on the dash is more like 60 degrees C actual temperature from memory.