Replacing thermostat - broken plastic tabs missing in coolant system?

A6 All/ S6 All
#1

Hi all,

I’m needing some advice here. The thermostat went out on my 3.0T and I just pulled it out and found that the 3 plastic tabs had broken off (seems to be a common issue and how they usually crap out). Trouble is, I can only find one of them beneath the thermostat (or anywhere in the housing). I’ve fished around as much as I can and no luck. Do I need to flush the whole system now and hope they come out? I’m afraid it will just drain down into the block and get stuck somewhere. What a complete PITA and all due to some engineer’s terrible idea of using a plastic thermostat.

#2

It sucks that the thermostat goes out so regurally on the 3.0T cars like that. But its good your able to fix it.

If you can help with a picture of the area and the unit with the broken tabs it might help in giving you more direct information. What you could always do is add positive pressure on the back side of the coolant system to see if it pushes out the tabs. Your right in the fact you dont want the tabs stuck in the system.

#3

I agree that pictures of the thermostat and area in the block would be very helpful.

You can try flushing the system but most likely you will have to just install a new thermostat and hope for the best. Good thing that it is a fairly easy repair to replace the thermostat on the 3.0T. Just need two people to be able to safely lift off and set back down the SC so that it doesn’t accidently get dropped on the studs and puncture the intercoolers.

#4

Mine’s gone too, 2010 S4, just picked up a replacement thermostat and waiting for a little better weather to start. extra bonus is not having to pull the front cliup to throw my stage II pulley back on.

Curious if you had to remove the front coolant pipe or just push it out of the way to replace the thermostat. I hope my fingers are small enough.