MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Ranbeer Singh on December 20, 2013, 04:39:18 pm

Title: Coolant Temp
Post by: Ranbeer Singh on December 20, 2013, 04:39:18 pm
Hi All,

My oil temp doesnt seem to be hitting 90 as it used to.  I appreciate the weather is cold but normally it would hit 90 in 5/10 mins of driving... currently at the end of my journey to work which is about 20 mins, it is hovering around the 80 mark.  Im guessing the thermostat might need changing?? Also is this damaging to the car... any advice would be most welcome.

Thanks in advance.

Rick
Title: Re: Oil Temp
Post by: Llew on December 20, 2013, 04:50:23 pm
Oil or coolant?
Title: Re: Oil Temp
Post by: edd666999 on December 20, 2013, 04:51:30 pm
There have been some big threads on the thermostat in the past month.

Do a search there's loads of info on exactly your issue.
Title: Re: Oil Temp
Post by: Llew on December 20, 2013, 04:54:55 pm
http://www.mk5golfgti.co.uk/forum/index.php/topic,35900.0.html
Title: Re: Oil Temp
Post by: Ranbeer Singh on December 20, 2013, 05:09:34 pm
Sorry its the coolant temperature next to the petrol gauge.
Title: Re: Coolant Temp
Post by: Human Joist on December 20, 2013, 07:07:12 pm
You have described the common diagnosis of the main thermostat failing mate. Also if it is the main thermostat they tend to get nearly to temp when stationary at a set of lights or traffic etc and then when you drive off the temp drops.
Title: Re: Coolant Temp
Post by: Ranbeer Singh on December 20, 2013, 08:20:47 pm
This is why I love this forum !  :happy2:

Good solid advice!

Will this cause damage to the car if not replaced straight away?

Rick
Title: Re: Coolant Temp
Post by: Human Joist on December 20, 2013, 11:03:53 pm
Not directly. However the engine is more prone to wear whilst cold which is why you should never thrash it while cold and yours will take longer to get warm also mpg is worse when cold. There are 2 other minor thermostats on a dsg and 1 on a manual. They fail and stick open and the symptom is the car just takes ages to get warm but holds the 90 when it's there. I have this fault and will be replacing it next month.
Title: Re: Coolant Temp
Post by: vag12 on December 20, 2013, 11:07:07 pm
Change thermostat job done i know this fault very well
Title: Re: Coolant Temp
Post by: Chris01 on December 21, 2013, 10:56:52 pm
Just to confirm this, a friend has had the exact same issue. At traffic lights the idle revs were higher than usual to compensate for the "cold" engine. MPG went south. It was all good after changing the thermostat.
Title: Re: Coolant Temp
Post by: jamma on December 27, 2013, 07:42:31 am
Hi . I have the same problem , mine sticks at 70 degrees , any idea how much part is and how long to fit ? Cheers
Title: Re: Coolant Temp
Post by: Itguy on December 27, 2013, 07:58:56 am
Part is about £35 (if it is actually the main thermostat housing you need, rather than any of the other thermostats your car may have).

Changing main thermostat is about a 3-4hr job DIY depending on how good you are with the spanners and if you have all the right kit.
Title: Re: Coolant Temp
Post by: Wolf Burger on December 27, 2013, 06:47:24 pm
Whats the part number for the main thermostat?

06F121111F ??
Title: Re: Coolant Temp
Post by: Human Joist on December 27, 2013, 07:24:58 pm
On an early gti. 2005 model. Do I have to drain the coolant in order to change the main thermostat. I know I do for the smaller ones. Just wanted to confirm for the main
Title: Re: Coolant Temp
Post by: kylelnsn on December 27, 2013, 07:30:01 pm
This is why I love this forum !  :happy2:

Good solid advice!

Will this cause damage to the car if not replaced straight away?

Rick

Here Here!  :drinking:
Title: Re: Coolant Temp
Post by: Itguy on December 27, 2013, 07:35:58 pm
On an early gti. 2005 model. Do I have to drain the coolant in order to change the main thermostat. I know I do for the smaller ones. Just wanted to confirm for the main

Yes you do
Title: Re: Coolant Temp
Post by: Human Joist on December 27, 2013, 08:19:56 pm
Cheers bud
Title: Re: Coolant Temp
Post by: Itguy on December 27, 2013, 08:37:45 pm
It's obvious when you get in there but the thermostat is on the side of the engine block about half way down, probably in the worst position possible for DIY!
Title: Re: Coolant Temp
Post by: Human Joist on December 27, 2013, 09:16:41 pm
Am hoping I don't need to change that one. My car holds 90 when it gets there but it takes nearly 10 miles to do so. I was thinking it's the two smaller thermostats that have failed.
Title: Re: Coolant Temp
Post by: jamma on January 07, 2014, 01:12:00 pm
Part is about £35 (if it is actually the main thermostat housing you need, rather than any of the other thermostats your car may have).

Changing main thermostat is about a 3-4hr job DIY depending on how good you are with the spanners and if you have all the right kit.

Cheers , I need the cambelt done too,  so cambelt, water pump and thermostat is 480 quid so will get it all done at once.
Title: Re: Coolant Temp
Post by: Ranbeer Singh on January 09, 2014, 08:05:26 pm
Update.

Changed the main thermostat and car is back to normal  :driver:

Thanks chaps
Title: Re: Coolant Temp
Post by: Wolf Burger on January 09, 2014, 08:08:01 pm
Update.

Changed the main thermostat and car is back to normal  :driver:

Thanks chaps

Mine being done in the next couple of weeks.
How long and how much mate?
Title: Re: Coolant Temp
Post by: OSB on January 10, 2014, 07:59:07 am
VW Book Time is 3hrs.
DIY time seems to be 3-4hrs depending on skill, access etc - there is probably someone out there who has done it quicker though!
Title: Re: Coolant Temp
Post by: Ranbeer Singh on January 10, 2014, 12:26:18 pm
Quote
Mine being done in the next couple of weeks.
How long and how much mate?

HI Mate,

Got my mechanic to do it.

3hrs work
£80.00 labour
£30.00 thermostat
£5.00 coolant
--------------------
£115.00 all in

cheers
Title: Re: Coolant Temp
Post by: Human Joist on January 12, 2014, 08:42:22 pm
Right update. Drained the coolant and found a good place to do so of a link On here by removing a pipe on a low point and letting it all come out neatly. Did not bother with any proper drainage points. Then replaced both smaller thermostats. Both were completely knackered and I could not even move them with pliars. The only trouble I had was the clips were the wrong way round so could not get straight on to the spring part. Sorted filled back up and back on the road. Just want a cold star to check it's sorted.