# Replacing thermostat on the 2.0T (MKV?) is not fun...



## bripab007 (Jul 7, 2006)

I'm just posting to say that replacing the thermostat on the 2.0T sucks...big time. I knew it was going to be a nightmare going in, but, man, what a hassle. It's buried underneath so much, and these VW cooling systems just have WAY too many hoses and coolant routing.

Anyway, I'm glad I saved the ~$500 compared to the dealer cost, but it did pretty much knock out most of my Saturday.


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## MFZERO (Mar 13, 2002)

true story!


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## Boosted2003! (Mar 10, 2009)

I haven't done it before but from working on other parts of the engine. I think its a lot easier if you have a manual trans. 

Its still easier to change a FSI thermostat then a TSI.


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## bripab007 (Jul 7, 2006)

I have a manual trans, so I'd hate to think it could be worse. 

What's different about the TSI setup with regards to the thermostat?


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## jhines_06gli (Feb 3, 2006)

bripab007 said:


> I have a manual trans, so I'd hate to think it could be worse.
> 
> What's different about the TSI setup with regards to the thermostat?


TSI engines have that external water pump that is driven by the front balance shaft. So it's over by the starter area. Similar to the FSI, the TSI has the thermostat encased in that plastic housing....BUT the TSI also has the water pump in that same housing and is driven by a little cog belt. It too is sorta a PITA.

As for the FSI guys.......if you are tackling the thermostat, I would recommend a little more routine maint. and just take the intake off. While you are there, clean and reseal the injectors and clean the valves. It will make your car idle smother and have a smoother powerband without the buildup on the valves. It also makes the thermostat 80% easier to do and no alt. removal needed. I work on these cars every day and can personally take the intake off and replace the thermostat quicker than most people can do it just by removing the alt./boost pipe. It's a few more $$ for the intake gasket, cleaner and injector seals.....but why not do it all at once?
-J. Hines


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## bripab007 (Jul 7, 2006)

Good points, J.


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## MFZERO (Mar 13, 2002)

that's a great tip for the FSI cars :thumbup:


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## PragMastic (Jul 9, 2011)

Hey MFZERO, I will have a shop replace the thermostat on my 2008 MKV GTI (FSI engine). 

Can you please list all other part replacements / maint. work you recommend I get done simultaneously to save on labor costs? 

I'm at 56k miles. 

List the items that I will for SURE have to deal with soon anyway, regardless of how conservatively I'm driving the hatch. 

Thanks in advance!


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## cirus02 (Oct 15, 2007)

Anyone purchase the Mahle-Behr ES#2539277 Thermostat from ECSTuning? Just wondering if this includes the thermostat already installed in the housing or if the T-Stat is separate. 
Other than j's suggestion early about removing the intake and injectors, any other suggestions or DIY's that can help?
I have the VW repair manual and DVD, so parts and diagrams shouldn't be a problem.

Might need to be replacing mine. 2005.5 MKV 2.0T FSI manual trans with about 63k.

Update: Dealer says its 2006 2.0T, diag print says 2.0I R4/4V TFSI..


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## Sandman333 (Oct 28, 2002)

jhines_06gli said:


> TSI engines have that external water pump that is driven by the front balance shaft. So it's over by the starter area. Similar to the FSI, the TSI has the thermostat encased in that plastic housing....BUT the TSI also has the water pump in that same housing and is driven by a little cog belt. It too is sorta a PITA.
> 
> As for the FSI guys.......if you are tackling the thermostat, I would recommend a little more routine maint. and just take the intake off. While you are there, clean and reseal the injectors and clean the valves. It will make your car idle smother and have a smoother powerband without the buildup on the valves. It also makes the thermostat 80% easier to do and no alt. removal needed. I work on these cars every day and can personally take the intake off and replace the thermostat quicker than most people can do it just by removing the alt./boost pipe. It's a few more $$ for the intake gasket, cleaner and injector seals.....but why not do it all at once?
> -J. Hines


I just had all of this done at my dealer. Total cost was just under $700 and I supplied the thermostat from the Blauparts timing belt kit. No doubt that thermostat is a PITA to get to. My dealer actually suggested doing this and the valve cleaning at the same time as it would save me labor costs. My original thermostat was starting to stick open, such that the engine could not maintain 200* operating temp unless i kept it above 2000 RPM in weather as warm as 50*. It would drop down to less than 160* and I would barely have any cabin heat. It's all fixed now 

Sent from my XT1585 using Tapatalk


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## _Riddle (Oct 16, 2015)

I did mine a few months back and it was tedious, but it wasn't too bad. The worst part of the job is when I stripped a triple square bolt that was holding on a hose bracket... You really need to make sure that the tool is fully seated. It also helps to use regular socket extensions and NOT wobble extensions. That added an extra 2 hours onto the job. The alternator was also a little suborn to remove, and an absolute bear to get back on. I'm glad I did it myself. It was a good learning experience. My next job will be a valve cleaning and possibly a cam chain tensioner replacement as preventative maintenance.

You also have to be very careful when installing the new thermostat. The portion of the cylinder which it installs onto has a sharp edge and can easily tear the gasket. Go slow and apply even pressure when pushing the housing onto the engine.


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## Eye Candy White (Nov 9, 2006)

I just had this done at my local performance shop - parts and labor for a total coolant system refresh (minus the radiator) was $499.

They hadn't done a MKV GTI before (they're primarily a Subaru and BMW shop but work on all kinds of cars), and they said it was a bit of a pain in the butt.

I know they did remove the intake manifold, which sounds like makes it easier to get to. Stupid plastic cooling system parts...


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## cirus02 (Oct 15, 2007)

jhines_06gli said:


> TSI engines have that external water pump that is driven by the front balance shaft. So it's over by the starter area. Similar to the FSI, the TSI has the thermostat encased in that plastic housing....BUT the TSI also has the water pump in that same housing and is driven by a little cog belt. It too is sorta a PITA.
> 
> As for the FSI guys.......if you are tackling the thermostat, I would recommend a little more routine maint. and just take the intake off. While you are there, clean and reseal the injectors and clean the valves. It will make your car idle smother and have a smoother powerband without the buildup on the valves. It also makes the thermostat 80% easier to do and no alt. removal needed. I work on these cars every day and can personally take the intake off and replace the thermostat quicker than most people can do it just by removing the alt./boost pipe. It's a few more $$ for the intake gasket, cleaner and injector seals.....but why not do it all at once?
> -J. Hines


Any idea as to where I could find a DIY for doing this? I replaced the sensor, but the CEL came back on and my temp gauge is not reading right again. Going to remove the intake and replace the T-stat, anything else I should replace or swap with AFM parts:?


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## Thy_Harrowing (Dec 7, 2014)

cirus02 said:


> Any idea as to where I could find a DIY for doing this? I replaced the sensor, but the CEL came back on and my temp gauge is not reading right again. Going to remove the intake and replace the T-stat, anything else I should replace or swap with AFM parts:?


Not sure about DIYs for the T-stat job but if you are taking of the intake manifold to do carbon cleaning then the t-stat should be pretty straightforward... as for DIYs for removing the intake manifold there are a few floating around but the god of all of them is the "STASIS" guide. Google "STASIS VW intake manifold guide" or something to that affect and you should find it. If it isn't floating around anymore I might be able to dig up the PDF of it that I downloaded a few years ago when I did my cleaning.


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