2008 vw jetta low temperature on gauge

[s900t8v]

Can someone confirm. Is there only 1 thermostat on this model?

[Umai Naa!!]

Correct.

[Cheezel]

I have an OBD reader in my TDI, and it's interesting that the gauge shows a solid 90 for a coolant temperature the computer is reading from about 75 up to about 105 (long hill on the freeway). So, if you're reading about 70, it could be quite a bit lower.

[Umai Naa!!]

The guage doesn't entirely correlate to what the coolant temp is actually doing.

[JustCruisn]

The gauge is "weighted" so it will show 90 when in the nominal range.
I have found it will sit at 90 until temp goes over 105, the alarm sounds shortly after that at which time a tow truck needs to be called.

[s900t8v]

Anyone got an estimate of how long this job would take ?

Remove alternator then it's easy to get to right ?

[s900t8v]

Anyone got an estimate of how long this job would take ?

Remove alternator then it's easy to get to right ?

HA

well this was a nightmare job! should have tried to find the manuals recommendations for th job!

took me about 5 hours on the BVY motor because I didnt know how to approach it

Anyway now I have a car that reaches operating temperature really quickly and stays there even on the highway it doesnt move off 90! THANKFULLY, fresh load of coolant in... while I was doing the job I noticed the battery + was rubbing on the frame and shorting, could have started a fire.. thankfully didnt - anyway I fixed that too


so what I did

- removed the bumper
- removed the R) wheel arch trim
- removed the windscreen washer bottle
- locked the tensioner remove the belt
- removed the VW labrinth piece on top of the intake manifold - pry out/off the emissions lines
- moved the charcoal canister out of the way to get to alterantor bolts easily

- jacked the car up and support on jackstands
- removed the two bottom bolts for the brace that holds the intake manifold onto the block you dont need to undo the top braces - (these increase the clearance available for the rigid pipe that goes into the thermostat)
- removed the air con compressor 2 pin plug and the bolts and let it hang down carefully
- removed the alternator 2 pin plug before undoing the alternator. you can leave the 12V line connected
- removed the alternator bolts and pry it out and sit it on top of the air con compressor so nothing is stretched

- removed the lower hose clip on the thermostat and pull the hose clear - splash of dirty old useless coolant
- removed the torx screw holding the rigid heater pipe in place in the thermostat housing
- removed the 4 clamps holding the intake manifold rubber bellows
- removed wriggle and cursed the unit out of its home and disposed of it in a way that is the most satisfying
***the thermostat I bought came with a block mating o ring but not a rigid pipe o ring (so dumb)
- greased with vaseline
- installed new thermostat with rigid pipe assembly


- reassembly reverse of removal!

[Umai Naa!!]

Woah...

I should've gotten to this sooner.

Pretty much everything is done from up top, besides removing the undertray to drain the coolant. Don't need to remove the bumper, the A/C compressor or anthing like that. You do need to remove the alternator, which is easy enough. It does fit out the top once you've unhooked it. Probably a 2hr job tops, including burping the coolant.

[s900t8v]

haha well ya didnt so not much use are ya! haha just kidding of course

all good got it done its a mates car now anyway I just sorted it out for him to save him some cash...

the lack of clearance makes it a pain of a job... are you saying you removed the intake manifold? I can see it being easy/from the top if that was what you are supposed to do. but couldnt find service instructions anywhere so I went from the bottom partially because I had the bumper and skins off for plastic welding anyway but partly because I though the intake manifold would be too much of a pain to remove - in hindsight it would have been much easier! oh and the car doesnt have an undertray dunno where it went haha so maybe thats why I thought it would be easier to go from bottom

[MEL744]

For future reference I think this guide is for the 2.0 na engines, although no specific codes are given. MK5 FSI Thermostat Replacement How-To | Club GTI Need to do this on my Jetta also a BVY.