take my word for it as mine broke at 89k....the main thing that causes this is the pulley tensior and the plastic water pumps...both are upgraded when you buy the timing belt kits. trust me 300 bucks and 7hrs of work is better than $5500 for a rebuild(audi dealership)
as for the coolant the radiator has a drain screw located on the bottom of it near the drivers side. coolant draining procedure is pretty much the same for most cars. use distilled water and have heater on full blast for the flush and then add your g12 coolant. run car for a little bit and make sure to add more coolant when the level drops. also i bought a new coolant expansion tank(has new sensor inside) because mine was ugly and i could see the contact inside was a little dirty...giving false coolant readings ttstuff.com and ecs.com both sell it for like 20 bucks. very easy to install yourself

 

HVAC is your climate control


To use your HVAC to monitor the coolant temp (in celcius):


- push the recirculation button and up arrow at the same time.
- use the temp adjust **** and find block/channel 49
- push recirc button (this shows your engine temp in celcius. 88-93 is normal while running)
- push the recirc and up arrow again. (to switch back to regular hvac mode)

 

By "recirculation button" do you mean the one on the AC control?

I need to check mine as my gauge is doing the same thing. It started out just above the halfway line and now settles in at the last line before. I changed the temp sensor to the green one and that didn't fix it. I tried to take it to a place and the guy refused to look at it, telling me the cluster is known to go out and give false readings and he didn't want to deal with replacing it. I think when I first started having this fun problem someone mentioned how when the car starts overheating the needle doesn't just creep up, it'll jump to the first line and if it gets past another temp it'll just to the next line and so forth.

 

to bleed the system of air dont you just idle the car with the coolant resevoir open?

 

Yes the recirc button on the AV/climate control. When you turn the key to the "on" position... does the temp gauge immediately go to about 1/4? If so then yes its your gauge cluster... its not a big deal and i would recommend waiting until more of it *** up to get it fixed

 

my extended warranty covered my replacement. i just took it to the dealer, paid the $100 deductible and got a brand new cluster.

 

CPO or 3rd party extended warranty?

 

third party.