Hi Everyone,

I have a 2004 TT 225 and recently the needle on the Temperature Gauge has been moving the the next notch past the Center mark and pretty much settled there.  Since I just past my 65k mark I figured

it was time to get the timing belt kit installed.  Ordered the ECS Ultimate Timing belt kit that came with

the Timing belt, Accessory belt, Waterpump with metal impeller, Behr Thermostat, Tensioner, and all the

rest of the usual stuff.  I had it installed by a reputable VW/Audi/Porsche Tuning shop here in Indianapolis for just 400 bucks.   Anyway, to make a long story short.  After the Thermostat and the

Waterpump were replaced the needle of the Temp Gauge still wandered off to next notch past middle.

I then went to the Audi stealership and got myself a new Temp Sensor, thinking it would be bad but

after installing it the needle still persistently goes past the middle and settles just a tad past the next

notch over.   The car runs great otherwise.  What is the normal operating Temperature when the car

is fully warmed up?   I did install a digital gauge and my readings are right at 204-206 degrees and if

I sit in traffic at rush hour it has gone up as high as 211 but never higher. 

I checked my coolant level and it is fine, no oil in the coolant or coolant in the oil so it isn't a head

gasket.  I just don't know what else it could be?   Any ideas?  

If anyone could post their operating temperature when fully hot I would greatly appreciate it.

Thank you in advance for any suggestion and ideas.

Tom in Indy

04 Red Audi TT 225

I own a 02 225 Roadster and it stays pretty much in the center. When it does go up a notch the fan kicks in and it goes a notch or so below center. I live in Southern California and I too sit in traffic in the hot weather. Since you have pretty much replaced your entire coolant system including what could have been deteriorating coolant I would focus on what would make your engine run hotter. (ie bad oil, diminished air flow due to a bad sensor or filter, etc)

I would recommend redline water wetter. It will help your engine run a few degrees cooler. I use it with all of my cars and it works wonders in my motorcycle.

I was told never ever to run Water Wetter or any sort of Additive along with the G12 Coolant in the

Audi.  It will either turn brown or be otherwise rendered useless.  Some say that the combination will

harm your radiator.   I never tried it myself and I am afraid to after the comments I read about

Water Wetter in Audi's coolant system.

I think it is my dash gauge itself and not anything mechanical.  I use Castrol 0W30 European Formula Motoroil and it has always worked very well Summer or Winter.  I always change it every 3000 miles or 3 months whatever comes first.  The airfilter is an AEM Dry Cone Filter that I clean on a regular basis.  I did have one of the Cooling Fans replaced and both fans run when I turn on the AC so I know it can't be that.    So I am thinking an error with the Dash gauge. 

Water wetter claims to be compatible with all types of coolant. Mine isn't brown at all. I've had no problems.

Are you using and aftermarket Coolant?  Because I was told by several sources that never ever to use any sort of additives with the Audi G12+ Coolant.   The Coolant will turn into Mud, clog and destroy your radiator and make your Audi Selfdestruct  

I may try some Motul Coolant along with their MoCool additive.  But I am now certain that it is my Temp Gauge that is at fault.  I am getting a steady reading and when starting the car first the needle is already past the first click and those gauges are notorious of going bad and throwing incorrect readings.  My digital Scangauge II is reading a steady 202-204 degrees Fahrenheit or about 94-95 degrees Celcius which seems to be Normal for our cars.