running very cool

Hi :
I have an '06 and since the timing belt relacement at 95m recently, the temp gauge stays at 120' when driving, then will go up slowly at idle to 190. The mechanic says the water pump was replaced. Milage seems to be OK, and she seems to feel good and the same when running. At the same time the cars heater seems to suck now that it's 20' out here in PA, any ideas??? I didn't go to a TDI mechanic but a friend at Toyota. I am concerned I may be doing damage, and really have no clue where to start..the thought of going to a dealer is frightning!
Any help or suggestions would be so appreciated, thank you! Captainart

You need a new thermostat. Yours is not closing.

Bill

Thanks, does that involve removing the altinator../ Really appreciate your help, captainart

It's really odd that your car will actually warm up all the way to 190 at idle. My temp actually FALLS when I'm sitting. I'm not saying 40X40 is incorrect. It's just odd the problem surfaced after a timing belt and water pump change. I have a few concerns for you to consider:

1) Your friend, while likely a competent mechanic, probably used what we call the "mark and pray" method for changing the timing belt. This works on a lot of cars. But the TDI actually needs to have certain parts pinned into place (at TDC) for correct mechanical timing; and then the injection timing needs to be checked and adjusted with VCDS. You should take your car to a TDI guru and have this checked.

2) Please tell us your mech didn't put green coolant in your VW. If he did, you'll also need a total flush and put the right stuff in. The green and pink coolants do not mix well.

3) Again, not suggesting there's nothing wrong with your thermostat. But I'm hung up on all of this starting after a TB and WP change. I wonder if either the water pump is faulty (impaired, not failed) or if bad timing could actually cause any of your symptoms. Just a thought that smarter people may comment against.

Good Luck,

Scott

Hi Scott; Great list of item to start with. Hoping it is just a thermostat and end of story. I'll get started on it and post results as I get it sorted out. Thanks 4ox40, also!
regards, captainart

I'd guess that 40x40 is right. This is the time of year to have cold thermostats.

The thermostat is easy to get to.. 2-10mm headed bolts. Thermo comes out with the flange. Check to see if it is closed when you pull it. Replace with a 85c thermostat. That is my choice.

Otherwise, this time of the year, I am blocking off the radiator to help the engine warm more quickly.

hi Frank, thank you for your reply. I just spoke to the dealer and they said it's a 3 hour job, what do you think??
Thanks again, Art

captainart said:

hi Frank, thank you for your reply. I just spoke to the dealer and they said it's a 3 hour job, what do you think??
Thanks again, Art

Click to expand...

That seems a little excessive to me but I haven't replaced the thermostat on my Beetle. Of the thermostats that I have replaced, they have all taken very little time to change. I would HIGHLY discourage going to the dealer unless you have a warranty. They are notorious for really causing more harm than good for our TDIs.

contact a TDI Guru close to you and see what they have to say if you aren't planning on doing it yourself. Just my $.02

Thanks, your $.02 probably saved me $300!

Thermostat is a cheap easy fix. Dont let any dealer tell you that it's a 3 hr job. That's why people call the dealership, the stealership. Even if the thermostat doesn't fix your problem it's $15 - $20. I would replace it any time I'm doing a water pump on any vehicle just because I have the system drained at the time any way. Timing check on VCDS is very important! I would have it checked eaven if the thermostat fixes your problem.

Good luck buddy.