MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Human Joist on January 24, 2014, 09:16:58 pm

Title: How to change your inline thermostats.
Post by: Human Joist on January 24, 2014, 09:16:58 pm
Right. I have had a problem recently whereby my car is taking an age to warm up. Getting to work 9 miles and it's not even reaching 70 degrees so I did a lot of hunting round and found a few bits but no guide so thought I would post one up. The pictures were taken after the work so I will explain what's going on. I discovered that our cars have more than one thermostat. Mine is a 2005 dsg model so actually has three. Manuals only have two so as you can guess the third one is for the dsg box. They don't open till engine is up to temp so obviously this will stop the car reaching temp as the flow will not be restricted when cold as VW intended.

Anyway first things first. You need to drain the coolant. Apparently there is a few purpose designed drainage points that tend to break when opened and also are hard to get too. I discovered on an American site (although a long-winded thread the coolant drainage point was very good)

Jack the car and remove the reservoir cap then underneath the car between the sump and the radiator you will see this little gem. Seperate pipe from the unit. (Yellow and red arrows) then leave for the coolant to drain. Obviously it goes without saying leave the car to bee completely cold as red hot water is not nice on the face.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2F80982E90-8173-41BC-8E11-A5D00E0DB9B3_zpsoo5xbwms.png&hash=cd4e23a946f27c35212538342a19f1b84bd50fc7)

Now that's done we will remove the inline thermostats. First remove the engine cover for more view and access. Starting with the gearbox if you look at the engine between the battery and air intake. You can just about see it in the middle of the picture.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2FE6A91800-3F37-4A8A-8C52-720E28024314_zpsqc8jj84a.jpg&hash=ba46082a2d9fdbd9dc9d4b78f35cac60216dc714)
They look like this but black
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2F691BE623-251C-485D-90D7-0704C71330FA_zpsjd2phmn1.jpg&hash=401056d798438a9e0886f4b9f2665032a12717d3)
 And zoomed in you can see the stat in the middle of the pic under the plug. Remove the plug then undo the spring clips with mole grips or similar and then you can take the stat out swap and replace. The spring clips can be alkwood depending on which they round they are but all manageable. This one is easy to swap.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2FD5B74A0D-C646-4A57-8B82-FA6D48940F1C_zpsnv9kvgql.jpg&hash=9e84ddfe0016708dacd1a0e9ce76959f6df132e2)

Now for the other one infront of the engine. A bit harder to do but not rocket science.
Once you find it it's easy from there.
It's down under the dip stick vertical.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2FF17B3A69-0A47-48EB-8887-CD0E2DA1A17D_zps6mmkbgda.jpg&hash=f9684e2501bed87f547be72442316c1dbb565bbc)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2F1C091A68-6D13-46FA-87F8-25D6FAD45DD3_zpsoi1g2jmx.jpg&hash=068fdf598fa1d1e613c1a0fcc182da45c62c124a)
Closer view again
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2F03BBA26E-BA8F-4E35-B95F-FE63B9576156_zpsksjokrsr.jpg&hash=faedbde4dd85b058e96c8d6e5cc9ad1a871c4f44)
Don't worry about how tight it is you don't need to strip the car back. I discovered an easy way. Underneath the car undo the spring clip for the pipe bellow the stat and seperate then go back above and you will see the metal pipe that comes from the top of the stat. Trace it back to here pointy finger job
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2F104E7ED6-A06B-470B-A3A1-780C42BB57EF_zpszqbvr2ih.jpg&hash=5f0ba36d76abb0765c28004035e2a20471c0a36e)
Move a pipe and undo this spring clip in the middle of the pic that's rubber pipe on to metal pipe
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-01%2F0F70FB64-4008-4433-80E5-448316C1FF24_zpsmnwywidc.jpg&hash=a26bdcf7571996c049c0a382defd255385143f22)
Now there are two bolts holding the metal pipe on. One is in the middle right of this picture and another one further round towards the front. With this loose, this pipe will come up and out of the way with the stat still attached. It's a little tight to get out and then in but by far the easiest and quickest way. Once it's out change the stat and then reinstall.

Both of mine were open so I could blow through them while cold and I could not close them with mole grips squeezing the life out of them. Well seized open.

Next when the pipes are all back on its time for the coolant. Use G13+ from VW. Nothing else is better and it's not that expensive. The two stats and the two bottles of G13+ were about £60 with trade discount can't really recall the price now. I put one bottle in neat then filled the bottle with tap water (no need for distilled) then tip that in. Next split the next bottle in half with the now empty one and top both up with water. This will have given you 3ltrs of 50/50 in the car and 2 bottles of 50/50 ready mixed. Simples. Now top the car with coolant and then run the engine till it reaches 90. Check the level and then go out and have a drive taking the coolant with you just in case. After a little drive leave it overnight. Check the level and top up.

I had to do this twice to get the level right. Now the car heats to 90 in about 3 miles even in the 5 degree temp.

I have had a few beers so hope this reads ok. Let me know if you need any more info or advice. Or if it's not clear.


Title: Re: How to change your inline thermostats.
Post by: Scottymon on January 24, 2014, 09:21:39 pm
Fair play to you mate, thanks for the DIY. :happy2:
Title: Re: How to change your inline thermostats.
Post by: OSB on January 25, 2014, 07:29:15 am
Very clear write up and pics. Thanks!
I will giving this a go as soon as the weather improves.
Title: Re: How to change your inline thermostats.
Post by: SkyJawa on January 25, 2014, 11:48:51 am
Nice one mate - good write up  :happy2:
Title: Re: How to change your inline thermostats.
Post by: doylebros on January 25, 2014, 03:42:34 pm
Cracking job there mate-  that should help people - even better if someone makes it a sticky in the "How to Guides/Troubleshooting".
Title: Re: How to change your inline thermostats.
Post by: xjay1337 on February 08, 2014, 12:40:40 am
Really good guide here.
Hadn't read it before.
Linking to the DIY thread.
Title: Re: How to change your inline thermostats.
Post by: Human Joist on February 08, 2014, 08:27:26 am
Found this the other day. Worth getting for the hard to reach spring clips. Will save some time. It's purpose designed for the job with a ratchet so once you have the clip it won't pop off. Available most parts places I should imagine. Just ordered mine.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FMobile_Uploads%2F2014-02%2F7C26E683-007F-4FE8-B439-F50C22355746_zpszrp6ikje.png&hash=10510851bd4c9a4a599a1a2d3a9aa3580ba05600)
Title: Re: How to change your inline thermostats.
Post by: SkyJawa on February 08, 2014, 10:14:37 am
Got a link?
Title: Re: How to change your inline thermostats.
Post by: Human Joist on February 08, 2014, 11:13:50 am
These are from draper direct. They are on eBay and most parts places sell them.

http://www.drapertools.com/b2c/b2citmdsp.pgm?pp_skmno=89793&ipadd=83.217.166.151

Any draper stockist can get these. You may be able to do it with normal tools like I did. But if one is hard to get to you can save lots of time with these.
Title: Re: How to change your inline thermostats.
Post by: 06Hirons on February 11, 2014, 01:15:08 pm
Does anyone have the part number to hand for the one of left hand side of engine?
I have a manual, so only need the part number for this one.

Thanks
Title: Re: How to change your inline thermostats.
Post by: SkyJawa on February 11, 2014, 02:06:58 pm
The coolant regulators be it 1 or 2 are the same part:

4E0 121 113
Title: Re: How to change your inline thermostats.
Post by: exodus_ste on September 22, 2014, 01:48:52 pm
Does anybody know if these are the same for the standard GTi and an Edition30?

I think i read that the main thermostat for the Ed30 has a higher opening temp.
Title: Re: How to change your inline thermostats.
Post by: lukemk5gti on October 14, 2014, 09:05:26 am
@Human Joist (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=8348) you seem to be the man on this issue. From looking around your name is popping up everywhere!

Tell me, I have a 2005 manual so only 2 thermostats correct? Do I have 2 inline thermostats but one is classed as main and the other is the bypass?

I can't really tell from your how to, which one is the "main" thermostat that people keep referring to as the culprit?

On your how to, your first pic says "Starting with the gearbox if you look at the engine between the battery and air intake. You can just about see it in the middle of the picture" Is that to say that this is the third dsg gearbox sensor you're tackling?

Thanks!
Title: Re: How to change your inline thermostats.
Post by: hunter2003k on December 08, 2014, 12:10:53 am
While im replacing my cylinder head i thought i would change both thermostats on my golf, however my 2005 55 plate dosn't have an inline thermostat, has anyone else noticed this?
Title: Re: How to change your inline thermostats.
Post by: Jonnyboy on December 27, 2014, 01:11:53 pm
Can you only get the in-line cooling regulators from the dealers?
Title: Re: How to change your inline thermostats.
Post by: dajonic on January 21, 2015, 12:47:15 pm
£24.61 for the inline temp regulators from VW and £19.27 from ebay. Part no 4E0121113
Title: Re: How to change your inline thermostats.
Post by: Tfsi_Mike on January 21, 2015, 01:07:41 pm

Great guide.
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on April 29, 2015, 03:06:19 pm
Bumping this one back up. I have a 2005 AXX manual which I assume means I have only got 1 inline stat. If so which stat do I have, the one to the left of the engine or in front?
Title: Re: How to change your inline thermostats.
Post by: dazza on April 29, 2015, 03:11:36 pm
Think you have two. One behind alternator and other by the battery.
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on April 29, 2015, 03:12:20 pm
I thought it was only the DSG that had two?
Title: Re: How to change your inline thermostats.
Post by: dazza on April 29, 2015, 03:14:15 pm
If you read the original post DSG has 3
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on April 29, 2015, 03:22:26 pm
I have but the guy has a DSG and he only gave instructions for replacing 2 of them?
Title: Re: How to change your inline thermostats.
Post by: dazza on April 29, 2015, 04:10:32 pm
Sorry by the looks of it there is the main stat. And two inline for DSG so one for manual.
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on April 29, 2015, 04:52:30 pm
I'm really struggling to find where my one located. It's definitely not on the gearbox end as there are no coolant hoses there and I can't see the one in front of the engine either. I can see the metal pipe that goes down the engine is it near that?!
Title: Re: How to change your inline thermostats.
Post by: dazza on April 29, 2015, 06:03:12 pm
this may help http://www.mk5golfgti.co.uk/forum/index.php/topic,75756.msg798616.html#msg798616
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on April 29, 2015, 08:17:13 pm
Thanks @dazza (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=10457) I had a look at the pics on that post and I'm either blind or my car doesn't have an inline thermostat.

Can someone look at my pics and let me know

<iframe width="480" height="360" src="http://s606.photobucket.com/user/phil_eagles/embed/slideshow/Car"></iframe>
Title: Re: How to change your inline thermostats.
Post by: dazza on April 29, 2015, 08:42:41 pm
Wait a week or so. As i'm doing the main thermostat and both inline ones i will take some pics of exactly where it is.
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on April 29, 2015, 08:44:46 pm
Nice one, thanks.
Title: Re: How to change your inline thermostats.
Post by: waynos on May 03, 2015, 02:54:03 pm
Ive just done my cambelt, water pump and both the thermostats. Mine is an 05. Ur inline stat is pretty easy to locate. Heres a pic to help u. If u imagine ur car didnt have the front end on its on the pipe to the left of the throttle body pipe.  I took a couple pics. Its on the pipe with the yellow writing.  The actual stat is next to the wiring loom

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fwaynos%2FMobile_Uploads%2FF9D0310A-CAF1-45CF-828C-029B7E673BB6_zpsftxzyk7f.jpg&hash=b118683f4bf6e863c7b807817ad9b9f75a17fd7c)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fwaynos%2FMobile_Uploads%2F3285A16A-3074-41F9-94C8-ABD2CC0A6D4E_zpsxb5gngdh.jpg&hash=3af74f442e798afacb5d72e913d3a02012f690e9)

Dont even bother trying without hose clip pliers
Title: Re: How to change your inline thermostats.
Post by: dazza on May 03, 2015, 03:23:54 pm
I bought the pliers last week by the looks of it they will come in handy.

Was the main stat as much of a pita as people say?

I'm about to change the cam belt, water pump, main stat and inline ones. Any tips would be appreciated.
Title: Re: How to change your inline thermostats.
Post by: v4rley on May 03, 2015, 03:37:37 pm
To change the front inline (pictured post above) I removed the lower pipe further back and pulled it up throught the engine to access the clips easier.

With regards to the main stat you should breeze it being a confident DIY'er, I have managed to change it, just takes a bit of time to access it  :happy2:
Title: Re: How to change your inline thermostats.
Post by: waynos on May 03, 2015, 04:01:28 pm
Main stat is easy enough. Alternator needs to be removed. Make sure u get some triple square bits. I think its a 5mm. Mine had two of these tiny screws securing the middle pipe to a bracket. You will also need a t30 torx bit to remove it from the stat itself. Lets hope your water pump hadnt been silicone sealed in place like mine. This is what greeted me when i got the bottom crankshaft pulley off

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fwaynos%2FMobile_Uploads%2FA78A0EB4-7237-4C83-AB07-ED0061BE1B76_zps7gr4b6f8.jpg&hash=651bccaa9d5b356061c48ade8b603017e461c739)
Title: Re: How to change your inline thermostats.
Post by: dazza on May 03, 2015, 05:28:07 pm
Main stat is easy enough. Alternator needs to be removed. Make sure u get some triple square bits. I think its a 5mm. Mine had two of these tiny screws securing the middle pipe to a bracket. You will also need a t30 torx bit to remove it from the stat itself. Lets hope your water pump hadnt been silicone sealed in place like mine. This is what greeted me when i got the bottom crankshaft pulley off

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fwaynos%2FMobile_Uploads%2FA78A0EB4-7237-4C83-AB07-ED0061BE1B76_zps7gr4b6f8.jpg&hash=651bccaa9d5b356061c48ade8b603017e461c739)
That looks nasty. She must be running better now?
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on May 03, 2015, 06:36:28 pm
@waynos (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=4541) thanks I think I light have located the inline thermostat now. Just to confirm the stat is located on the end of the metal pipe that travels down the engine?
Title: Re: How to change your inline thermostats.
Post by: waynos on May 03, 2015, 06:45:22 pm
Yea running loads better! Warms up quicker, maintains temperature, better fuel economy and hot air out the vents!

Gti eagles yea thats the pipe. You can disconnect it up by the cambelt cover. Undo the 10mm bolt on the inlet manifold and 10mm nut by the dipstick. And disconnect a hose clip at the bottom of the stat then pull the whole lot through. Otherwise your going to graze ur hands in the tight space!
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on May 03, 2015, 06:55:36 pm
Top man. Yeah it does look really tight thanks for the tip. I'll get this done soonish.
Title: Re: How to change your inline thermostats.
Post by: dazza on May 20, 2015, 11:13:24 am
Ive just done my cambelt, water pump and both the thermostats. Mine is an 05. Ur inline stat is pretty easy to locate. Heres a pic to help u. If u imagine ur car didnt have the front end on its on the pipe to the left of the throttle body pipe.  I took a couple pics. Its on the pipe with the yellow writing.  The actual stat is next to the wiring loom

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fwaynos%2FMobile_Uploads%2FF9D0310A-CAF1-45CF-828C-029B7E673BB6_zpsftxzyk7f.jpg&hash=b118683f4bf6e863c7b807817ad9b9f75a17fd7c)

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fwaynos%2FMobile_Uploads%2F3285A16A-3074-41F9-94C8-ABD2CC0A6D4E_zpsxb5gngdh.jpg&hash=3af74f442e798afacb5d72e913d3a02012f690e9)

Dont even bother trying without hose clip pliers


I've changed the inline stat by the battery. But can't find another one.

Are you sure an AXX engine with dsg would have two??

see pic below.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fimages%2F20150520_120520_resized.jpg&hash=1b80f9120417284f1cc2a4432c65082afad74838)
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on June 24, 2015, 01:42:32 pm
I have finally ordered the inline stat and I'm looking at replacing it either this weekend or next.

The coolant in my car has already been changed fairly recently so I don't really want to have to drain it all out if I can help it so I was wondering is it possible to plug the ends of the hoses that I will disconnect rather than draining it all out and filling the system again?
Title: Re: How to change your inline thermostats.
Post by: GTIEagles on June 30, 2015, 08:32:18 am
Managed to change my inline thermostat yesterday in the baking sun (not the best move!) Pretty easy to do apart from refitting the hose clips, as the mole grips just kept slipping off. Luckily Homebase is literally a stones throw away from my house so I ended up buying some screw in ones, replacing the impossible tension ones.

In hindsight I should have brought proper hose clip pliers but at the same time I'm not 100% on reusing the tension clips anyway.

So now my car hits 90 degrees in about 5 minutes whilst previously it would take 2-3 times as long.
Title: Re: How to change your inline thermostats.
Post by: ducman77 on October 25, 2016, 10:33:31 pm
Doing this job on Monday.
Hoping to do the main stat and the two inline stats.
2005 model AXX DSG car
This thread has been a godsend. Major respect, and a huge thanks to Human Joist and all the contributors :happy2:

Wish me luck!!
Title: Re: How to change your inline thermostats.
Post by: Carl123 on December 13, 2016, 04:14:20 pm
My stat is stuck so bought it today but when I asked about fitting someone has told me that I need to re-code the throttle body taking parts off is this true?
Title: Re: How to change your inline thermostats.
Post by: v4rley on December 13, 2016, 04:34:46 pm
My stat is stuck so bought it today but when I asked about fitting someone has told me that I need to re-code the throttle body taking parts off is this true?

Neither the inline or main stat require the throttle body to be removed so not an issue. Also don't believe it would need coding even if it was removed
Title: Re: How to change your inline thermostats.
Post by: Pesky jones on December 13, 2016, 04:38:06 pm
I have two brand new never inline stats for sale at just over half the price of brand new ones...just saying  :happy2:
Title: Re: How to change your inline thermostats.
Post by: Carl123 on December 13, 2016, 07:38:45 pm
My stat is stuck so bought it today but when I asked about fitting someone has told me that I need to re-code the throttle body taking parts off is this true?

Neither the inline or main stat require the throttle body to be removed so not an issue. Also don't believe it would need coding even if it was removed

Thank you this is what I thought I'm gonna go somewhere else to get it done also I was told it's about 3hrs labour is that right?
Title: Re: How to change your inline thermostats.
Post by: v4rley on December 13, 2016, 08:33:44 pm
Yeah fraid so 3hrs as it's deep in there  :sad1:
Title: Re: How to change your inline thermostats.
Post by: munster on December 29, 2016, 08:46:38 am
I have two brand new never inline stats for sale at just over half the price of brand new ones...just saying  :happy2:

ooooh tell me more please, cant pm as dont have enough posts yet
cheers
wayne
Title: Re: How to change your inline thermostats.
Post by: snowball05 on September 08, 2017, 10:36:19 pm
I just want to say thank to the person that provided this thread.  For 3 years I froze during winter on my drive to work.  Now the car heats up in 5 minutes of driving.  :happy2:
Title: Re: How to change your inline thermostats.
Post by: HITMAnsOFT on January 16, 2018, 07:09:24 am
Sorry for reviving an old thread, buuut I was thinking... there is a metal clip holding the two parts together, and ELSA suggests to open the housing to test the thermostat, so it's not impossible. What if, instead of working with those spring clamps, we just separate the two halves, while still in the car, and just change the core and the o-ring from the new stat? Did anyone try this way or does anyone know if it wouldn't work? I think I might try this when I do mines.
Title: Re: How to change your inline thermostats.
Post by: probedb on February 03, 2018, 12:25:53 pm
Ditto and thanks for the guide. For some reason my car had the main thermostat removed but now I have one, it gets to temp but takes a while. I'll get the inline one done soon :)
Title: Re: How to change your inline thermostats.
Post by: griff30 on February 03, 2018, 03:34:09 pm
Hi, Does anyone know for sure if a 2007 Edition 30 MANUAL has an inline thermostat?   

I was under the impression it was just below the metal pipe returning from the turbo, which is directly behind the radiator in the middle. Just above where the oil filter is.    The schematic they gave me at the dealers showed it there, but when I got home I just have a rubber hose, no thermostat in there to change...   
Title: Re: How to change your inline thermostats.
Post by: probedb on February 06, 2018, 01:26:10 pm
Should be able to see form the photos on the first page of this thread, it shows where it is :)
Title: Re: How to change your inline thermostats.
Post by: pudding on February 06, 2018, 01:58:46 pm
Hi, Does anyone know for sure if a 2007 Edition 30 MANUAL has an inline thermostat?   

I was under the impression it was just below the metal pipe returning from the turbo, which is directly behind the radiator in the middle. Just above where the oil filter is.    The schematic they gave me at the dealers showed it there, but when I got home I just have a rubber hose, no thermostat in there to change...   

Mine only has the 1.  Also a 2007 manual.

Title: Re: How to change your inline thermostats.
Post by: griff30 on February 07, 2018, 09:09:10 pm
Only the 1 as in just the main one? (the one that’s a barstewards to change - by the alternator)
I can’t find any others so I’m thinking I only have the main one despite it usually being said there is always an inline one also. At least I know which one to change if so!
Title: Re: How to change your inline thermostats.
Post by: maxamplitude10 on February 15, 2018, 11:24:10 am
Wheres the pics/ guide?
Title: Re: How to change your inline thermostats.
Post by: maxamplitude10 on February 15, 2018, 11:24:54 am
Wheres the pics/ guide?
Title: Re: How to change your inline thermostats.
Post by: Pesky jones on February 15, 2018, 12:34:27 pm
Wheres the pics/ guide?

First page?
Title: Re: How to change your inline thermostats.
Post by: maxamplitude10 on February 15, 2018, 12:58:32 pm
Oh I can't see the pics he is referring too......

Also does the edition 30 have 2 thermostats as Vw dealers are telling me it only has 1?

Thanks in advance
Title: Re: How to change your inline thermostats.
Post by: pudding on February 15, 2018, 01:27:37 pm
As above, manuals of the 2007 vintage only have 1.   And it's the one under the alternator.  I would replace the temperature sender as well because you don't want to be going down there again.  And also the seals.  I can't remember if the stat housing comes with them or not.

I found the easiest way to do it is to remove the alternator.  Once that is out of the way you have all the room in the world.  Iirc, I had to jack the left side of the engine up in order to remove the alternator, so you'll need a couple of engine mount stretch bolts as well.

Most people reuse them, but bear in mind there have been cases where the engine has dropped out of the car (most recently in Italy) from reusing the bolts.

Title: Re: How to change your inline thermostats.
Post by: maxamplitude10 on February 15, 2018, 01:41:59 pm
Thanks pudding I'll pick up some bolts and sender from the stealers....

Just need to find the source of my coolant leak now....... Goes from max to min in around 2000 miles...

Hope its not head gasket because I cant for the life of me find any physical leaks?!!!
Title: Re: How to change your inline thermostats.
Post by: Pesky jones on February 15, 2018, 02:22:52 pm
Any white smoke from exhaust?
Title: Re: How to change your inline thermostats.
Post by: pudding on February 16, 2018, 12:41:36 pm
Have a check around the plastic flanges that attach to the block under the chain cover, above the gearbox.  There’s an O ring that likes to go hard and leak.  The KO4 engines also suffer from a slight head gasket weep from the rear corner (pass side) of the head, which is what mines doing.  Mine takes about 6-9 months to drop from max to min.
Title: Re: How to change your inline thermostats.
Post by: Newbieintown on February 17, 2018, 06:39:50 pm
Guys does anyone know how much coolent it would need to fill back up the system? Also are there any bleed nipples to get the air locks out? Thanks
Title: Re: How to change your inline thermostats.
Post by: andyiseddy02 on February 25, 2018, 04:47:29 am
About 2 litres.
Title: Re: How to change your inline thermostats.
Post by: Octoparrot on February 25, 2018, 04:07:44 pm
So I went to change mine today thinking it'd be a nice easy job. It was, there isn't one! Which is a bit of a bugger as it means I'm going to have to delve into the depths and change the main thermostat.  :doh: if anyone needs a genuine inline thermostat drop me a pm £20 posted. By the way mines an 06 manual BWA.
Title: Re: How to change your inline thermostats.
Post by: griff30 on February 25, 2018, 11:20:13 pm
  Cheers for the info Pudding. Didn’t know I’d have to undo engine mount to remove alternator though... changing thermostat took 5 maybe 10 mins on my old mini!     
max amplitude:  VW call the inline ones “coolant regulator” or something very similar. They first told me only one but then when we looked I recognised the shape of the part under that name. But now it looks like I don’t have one anyway...
Title: Re: How to change your inline thermostats.
Post by: pudding on February 28, 2018, 11:40:39 am
No worries.

Yeah I also have a spare inline thermostat  :grin:

The main one is easy once the alternator is off.   It's a great opportunity to check / replace the serpentine belt, alternator clutch pulley and the electric after-run water pump  :happy2:
Title: Re: How to change your inline thermostats.
Post by: shaunK on February 28, 2018, 10:51:30 pm
Does anyone have a part number for the main thermostat? Thanks
Title: Re: How to change your inline thermostats.
Post by: Ollieeee on April 26, 2019, 04:06:38 pm
So I went to change mine today thinking it'd be a nice easy job. It was, there isn't one! Which is a bit of a bugger as it means I'm going to have to delve into the depths and change the main thermostat.  :doh: if anyone needs a genuine inline thermostat drop me a pm £20 posted. By the way mines an 06 manual BWA.

Bit of a thread from the dead but I’ve just had exactly the same thing. Went to change the inline down the front of the engine and there isn’t one! 55 plate manual so I’m pretty confused. Did changing the main stat solve it for you?
Title: Re: How to change your inline thermostats.
Post by: Octoparrot on April 26, 2019, 08:59:57 pm
Yes changing the main thermostat cured the problem completely but I did also change both temp sensors at the same time as well just to be on the safe side. Car hits 90 degrees and stays there regardless after about 3 miles.
Title: Re: How to change your inline thermostats.
Post by: Ollieeee on April 27, 2019, 03:18:11 pm
Yes changing the main thermostat cured the problem completely but I did also change both temp sensors at the same time as well just to be on the safe side. Car hits 90 degrees and stays there regardless after about 3 miles.

Great stuff, fingers crossed then.
Title: Re: How to change your inline thermostats.
Post by: Jamesf1010 on May 10, 2022, 07:22:25 am
Hi there, I've just acquired a 2007 GTI a couple of months ago and been having the same issue with the temperature gauge dropping.

I had the main thermostat replaced by a garage last week but this hasn't resolved the issue. It generally takes a good while to heat up and usually falls back when on the motorway / over 50mph.

I have looked at the 'secret' climate control menu the past few drives and it tends to be sitting around 66-70 degrees Celsius. It has been up to the high eighties but that was after a decent drive then sitting stationery for a while.

My heating works ok and have looked through the other threads and can't really see what else might be causing it other than a second thermostat also needing changed? Would changing the sensors be likely fix this or any other ideas as to what it might be?

I'm taking it back to the garage this week for another test but apparently there weren't any faults showing up last time that would have indicated a problem here so not sure what the next step is.

Any other ideas would be much appreciated.

Cheers