how hard is it to replace a thermostat on an 04 passat

[twigan1015]

my car never got over 90, didnt matter how long I drove it, then a check engine light came on, they did a scan and realize the themostat was faulty, it was left open, replaced it, got up to 190 quickly and stayed there, worked for about a week and now its back to 90, if I am correct it is probably my thermostat again, so I was wondering how diffucult is it to replace it, I dont feel like give the mechanic place a lot of money to fix something again, especially when it could just be an easy fix, does anyone know how to or am I thinking of the wrong thing here?

 

[vwztips]

They are easy to replace. Only 2 10mm bolts holding it in. Just be careful not to hit the positive post on the alternator with your ratchet.

Do you know if a VW unit was used? If not buy a VW tstat and install it. Have had too much trouble with aftermarket ones.

 

[squishbang]

The thermostat housing has two tabs that hold that t-stat and seal for installation. These tabs often break off when removing the housing because an old thermostat will be wedged in the block by the old, squished o-ring. If these tabs were not accounted for by the mechanic replacing the thermostat they very easily could have ended up wedged inside the new t-stat causing it to stay open.

 

[Mikey2]

Just be careful not to hit the positive post on the alternator with your ratchet.

Been there, done that

 

[Uberhare]

Walk in the park. Took me about 15 minutes in -15 weather.

As others have noted - watch out for the tabs. Have the new one ready to go and you can do it with very minimal coolant loss.

 

[Uberhare]

http://pics.tdiclub.com/data/3419/BHW_Engine_Thermostat_Replacement.pdf

from the faq.

 

[twigan1015]

thanks, seems pretty easy, I dont need to do anything with the coolant, do I?

 

[imo000]

Very easy. Did mine a month ago. I think the tabs were c
Gone on mine, made no difference, put the new thermostat into the block thrn the O ring and then bolted the platic pipe back onto the block.

 

[Mikey2]

The tabs are there to make sure that the thermostat is in correct orientation.

I no longer have the factory repair manual and I do not remember well, but the orientation of the thermostat should be so that the stat is not quite in upright orientation. Sorry, this is rather complicated to explain in words....

Whether the orientation makes any difference, I dunno. However, it is mentioned in the repair manual.

 

[imo000]

I think I put it in the block so it looked like the letter "I" as opposed to the negative "-" symbol. Works just fine!

 

[Mikey2]

If I remember correctly, the orientation should be such that the stat is a little bit off from "I". So, like "5 past 6" on the clock.

When removing the thermostat housing, it should be turned a little bit so that one could remove the housing while the thermostat (which is usually stuck to the engine block) would remain in the block - therefore without breaking the tabs. I did break my tabs - only later did I understand how it should have been done.

 

[JETaah]

The tabs are there so you can install all three parts as an assembly without fumbling with the oring and getting it pinched in there. The thermostat does not care about clocking.

 

[Mikey2]

Nevertheless, instructions for the orientation of the stat are given in the factory manual.

 

[imo000]

The tabs are there so you can install all three parts as an assembly without fumbling with the oring and getting it pinched in there. The thermostat does not care about clocking.

There wasn't any fumbling when I did mine but I lifted the driver side of the car up pretty high. I wanted to keep as much of the coolant in the engine as possible. This probably helped the thermostat from wanting to fall out during installation. It really was very easy even though my tabs were broken.