We've been doing this for a good few years together now and we're always finding out new quirks and learning about failures and the like. Here's a new one we learned last week. Got a call from a good friend/customer with a 2007 997 TT (highly modded) saying he was stuck in a parking spot and couldn't start his car. We loaded up the VW shop van with tools/supplies and ventured out into Ritzy Menlo Park. All the usual stuff checked out. The battery was fine. The clutch switch also. The ignition switch was in good shape (known to fail on 996s) as well. The starter etc... all had good signs of life. Fuel pump etc... all good too.

Here's you're problem, it comes in the size, shape and form of a very evil coolant temperature sensor on your engine.


I think we found the problem, made in


Anyways this particular blighter of a part (only $15-20): 997-606-420-00 reads the coolant temperature and when it decides to stop doing so correctly it will "protect" your engine and go into full lock down mode. You will not be able to start the car as basically the ECU isn't getting a signal so it's under the assumption that the temps are sky high.

Possible Symptoms & What to look for
We only started to get somewhere after chatting with the client for a while I decided to ask him if he had anything weird happen or check engine lights etc... He did tell me that his engine temperature gauge all of a sudden stopped working a few days ago for a minutes but that everything else was normal. After going through with the diagnostic tools we did see a registered P0117 code. So there you have it... if you've got your 2007+ GT1 block based GT3, GT2 or TT and you ever see your temperature gauge go on the fritz and yet everything seems normal BE WARNED. Major immobilization imminent!

You not only have to disconnect the battery in order to start the car but you also have to physically unplug the sensor. On a 997TT it's not at all easy to get to but on a GT3 it's somewhat tougher under the intake manifold.... Once you do start the car (don't stall it lol) and drive it somewhere to your closest dealer/shop and get the darned thing changed. Ask for one made in Germany maybe instead LOL...



And a couple of hours later back on the road:

 

why am i not surprised?

- chuck

 

It's always the cheapest parts that let you down, and the most difficult to replace. Thank you Alex for this hint and I'll probably have it changed just to make sure.

 

Good info Alex ! You the man