Author Topic: Coolant temperature  (Read 331 times)

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Offline dummer

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Coolant temperature
« on: November 09, 2017, 10:17:25 am »
What's the normal water temp in your GTI. whenever I cross the harbour bridge, I find the coolant temperature down to around 80 these days.

Worry if there is an air lock in the system.

Offline McDoof

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Re: Coolant temperature
« Reply #1 on: November 09, 2017, 11:24:53 am »
Had a similar issue with mine. Turned out that the thermostat was stuck partially open.
Does your car take a really long time to warm up?
NZ New MK5 GTI - Tuned by HSP Tuning

Offline Worms

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Re: Coolant temperature
« Reply #2 on: November 09, 2017, 11:53:53 am »
Very probably a poked thermostat, like McDoof says.

Pain in the arse job too! My Touran was the same, I got half way through the job, then just took out the whole engine and started on a conversion  ;D

If it's getting down to 80, it's actually much cooler than that too, because the gauges are buffered over a wide range.

Replace it, and you'll probably find your economy increases.

Offline The Red Warrior

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Re: Coolant temperature
« Reply #3 on: November 09, 2017, 01:07:21 pm »
Yeah, most likely the main thermostat is stuck open.
I replaced mine last year in my GTI.
There's a good diy guide that I followed at pelicanparts.com

Offline dummer

  • Posts: 76
Re: Coolant temperature
« Reply #4 on: November 09, 2017, 06:30:02 pm »
bummer...

I replaced cambelt last year together with water pump... would have thought they replaced the thermostat as well...

Other than taking longer to warm the car, are there any other down side?

Changing coolant mean I need to borrow my friends compressor for a vacuum fill because I have turned the radiator return pipe about 45 degree (to install my intake)


Offline McDoof

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Re: Coolant temperature
« Reply #5 on: November 10, 2017, 03:40:57 pm »
If it takes longer to get warm, it increases the wear on the engine. While the engine is cold it will also run a richer mix so fuel consumption is affected too.
NZ New MK5 GTI - Tuned by HSP Tuning

Offline GLIDN

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Re: Coolant temperature
« Reply #6 on: November 10, 2017, 04:29:25 pm »
bummer...

I replaced cambelt last year together with water pump... would have thought they replaced the thermostat as well...

Other than taking longer to warm the car, are there any other down side?

Changing coolant mean I need to borrow my friends compressor for a vacuum fill because I have turned the radiator return pipe about 45 degree (to install my intake)



No Thermostat is located in another location and is not usually specified as a replacement part. As far as a cambelt change is concerned.
Top Secret Project
MK3 GTI 16v Tornado Red - under the knife soon
Mk3 12v VR6 Variant
MK5 GTI DSG - Unitronic Stage 1 | Stage 1 DSG | Unitronic Intake |Tuned by HSP Tuning |
MK6 GTI DSG -  Unitronic Stage 2 | Stage 1 DSG | Unitronic Intake

Offline dummer

  • Posts: 76
Re: Coolant temperature
« Reply #7 on: November 10, 2017, 05:06:08 pm »
Did a quick google on DIY.
Sound like it's a b*tch to do it. either take the intake manifold off (and do carbon clean at the same time) or have to take the alternator off, then hope the plastic is not too brittle :(

Offline Worms

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Re: Coolant temperature
« Reply #8 on: November 11, 2017, 09:16:20 am »
Did a quick google on DIY.
Sound like it's a b*tch to do it. either take the intake manifold off (and do carbon clean at the same time) or have to take the alternator off, then hope the plastic is not too brittle :(

It's the dumbest place I've had to get to, just for a thermostat! They're not known for lasting forever either.

Offline dummer

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Re: Coolant temperature
« Reply #9 on: November 12, 2017, 09:51:11 am »
how long it took you last time?

Offline GLIDN

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Re: Coolant temperature
« Reply #10 on: November 12, 2017, 05:15:02 pm »
Did a quick google on DIY.
Sound like it's a b*tch to do it. either take the intake manifold off (and do carbon clean at the same time) or have to take the alternator off, then hope the plastic is not too brittle :(

don't need to remove intake manifold for the thermostat. Only the alternator has to come out.
Make sure the housing is seating in correctly before assembly. Otherwise you will be doing it again.

As I discovered on my own car, in my defense I was changing it at almost 3am in the morning.
So just be 100% sure.
Top Secret Project
MK3 GTI 16v Tornado Red - under the knife soon
Mk3 12v VR6 Variant
MK5 GTI DSG - Unitronic Stage 1 | Stage 1 DSG | Unitronic Intake |Tuned by HSP Tuning |
MK6 GTI DSG -  Unitronic Stage 2 | Stage 1 DSG | Unitronic Intake

Offline WEZO

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Re: Coolant temperature
« Reply #11 on: November 15, 2017, 09:36:21 am »
GLIDN - you never replied to my PM regarding o2 sensor?
2008 R32

Offline GLIDN

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Re: Coolant temperature
« Reply #12 on: November 15, 2017, 05:02:42 pm »
GLIDN - you never replied to my PM regarding o2 sensor?

Sorry not seen the message. Thanks for letting me know.
Top Secret Project
MK3 GTI 16v Tornado Red - under the knife soon
Mk3 12v VR6 Variant
MK5 GTI DSG - Unitronic Stage 1 | Stage 1 DSG | Unitronic Intake |Tuned by HSP Tuning |
MK6 GTI DSG -  Unitronic Stage 2 | Stage 1 DSG | Unitronic Intake