I am trying to figure out what the issue is.
The needle never goes above first mark on the bottom, I doubt its the sensor but I am wondering if possible somebody changed the thermostat to the lower for hot summer driving.
The car puts out pretty good heat, not blowtorch but good heat.
One thing that I do notice is the windows inside tend to fog up which is normally not a good sign.
I never have my windows fog inside with my heater on in my 90.
The floors are dry so I would likely say the heater core is not leaking but moisture is coming from somewhere.
The coolant itself was flushed and changed in May along with a new TB but they did not change the thermostat (stupidly).
Taking everything apart just to change the thermo is going to be a pain.
If only Audi could have put the thermo inline in one of the hoses, easy access and R/R.

 

one of the symptoms of plugged drain is wet carpet, which can make for foggy windows. A leaking heater core is another possible cause of fog....sometimes in a catastrophic event.

Run a self diagnostic on the climate control module. Maybe one or more of the motors or flaps aren't working right.

A thermostat can be changed without removing the timing belt. Search AustinAdo's posts for some great tips on that.

 

I did remove a bunch of leaves from the drains when I got the car but its always possible some are down there.
Could a clogged cabin filter have anything to do with it?
My guess is the owner had no clue one even existed, its probably baked with dirt, etc.
True the thermo can be changed without removing everything, it just can be tricky getting around the belt to the one bolt and the serp belt tensioner still has to come off but its possible.
Just ticks me off that this work was all done in May but the moron did not do a complete job, just a partial yet he paid full price for it.
His idea was "if its not broke, don't fit it", he failed to realize that certain Audi parts have a time frame in which they are changed regardless if they still function.
As for the cabin filter, if its like the 90 it should be under the cowling on the passenger side right over the blower. I can't see it being anywhere else.
Least it puts out some heat, the temp won't be over freezing till about April.
BTW Dave, I am 3 hours north of ya so we are in the same neck if you will.
This past summer I was walking around downtown SL and came across this russian fella who has a small shop in the back of a gas station and chatted with him. He wanted more then the dealership for common fixes.
The Audi's in his lot to be fixed are what drew me to go investigate.

 

Was he up in the Avenues near the University at 100 S 900 E? or closer to downtown?

 

maybe a few blocks from the hospital, the historical area with the brick streets.
A really small shop and not really an Audi shop but a general european repair shop
Its hard to say if he's good or not but it looks to be just him alone.
He quoted me about 900 for a TB change

 

A family friend recently bought a small gas station and convenience store that has a German car specialist repair shop attached and leased out to another guy. It looks like one long bay behind the convenience store that you'd miss if you weren't looking for it. A few BMWs, MBs, and a couple Audis parked outside most of the time. I've always been by there in the evening so have never met the guy in the repair shop. I don't know anything about his reputation.

Google maps tells me it's a couple blocks west of the SL Regional Medical Center, so it's probably the same one.

 

the other day the needle went up to the solid line for the first time.
strange, either the sensor came alive or the thermostat had some type of blockage and it broke free but everything seems normal now.