Blauparts timing/water pump kit includes a new thermostat that is rated at 87*C. I was talking to the shop manager at an Audi dealership about the auxillary water pump and he said that Audi made a change early on in the production of the 2.8L motor increasing the temp rating to 91*C due to incomplete combustion being caused by too low of engine run temps. Can anyone confirm this for me and why would Blau not have made this change as well??

 

really would like some help on this. FCP Euro lists three different temps for this engine...70*C, 87*C and 92*C. I used to think it really was not that important until the above mentioned shop manager said that engine run temps directly affect the combustion and therefore the carbon buildup on valves and injectors. I know what he said about running too low a temp but what would the negative affect be of running a 92*C versus a 87*C? From 70* to 87* is a big change, 87* to 92* not so much. Help please.

 

I have a 96 A6 with a 2.8 and it tends to drop about 3 mpg in the winter when the engine doesn't run as hot; considering it drives in 50 mile increments, it's not a matter of not running long enough.

I'd be hesitant about putting a 92 degree thermostat in if it is designed for 85/87 which is where almost all German cars appear to be set up for.

But I only have 227,000 miles on mine, so I could be wrong.

 

Your last sentence there sounds a little like.....my car has been running for 18 years so you could question me if you want to but youd be a fool to...

All in jest! I would say your track record with yours and the fact that I live in Texas where its about to get hotter than the 9 hells, I will stick with the 87*c one that I have. Needing the run a fuel system/ valve cleaning addative thru it is easier than what an overheat would do!

 

All I know is what I experience. Let's put it this way. If your Audi comes with an oil temp gauge, then you'll get to see a bit clearer what happens. When it gets hot out, you'll probably not see much change if any on the water temp. You will see it on the oil temp, which takes a lot of the cooling load. I've had a couple of thermostats that they have declared bad, but the way they have usually been found is by the oil temp.

The A/C kicks the dual fans on, and they ramp up and really suck voltage too at idle. But the bigger factor is that you pull the heat off the condenser, and onto the radiator, which is already fighting the engine heat and ambient heat. If you run at highway speeds, your oil pan doesn't quite get the radiant cooling that it gets a slower speeds - I guess it creates additional heat faster than it can lose it. Add that to the fact that my A6 turns over at 3000 at 65 mph and it is moving that coolant through the radiator pretty daggone fast, so fast that it has little time to give off the heat on the way through.

As far the mileage, well, I'm kinda in tune with what I experience...being the original owner. Question away, the worst I can do is shrug and go 'whatever'...

Enjoy.

 

That all makes good sense. The only reason I asked the question at all is what the Audi dealership shop manager told me about the original temp was 87 and they, Audi, increased it to 92 due to excessive valve fouling as a result of to low running temps. Prior to his statement I have never heard anyone say "my motor doesnt run hot enough". I have heard that you need to "REDLINE" high rpm motors from time to time to "blow out the buildup".
I had always heard that cold air is better since you would have more O2 molecules per square CM or Inch at colder temps than hotter and so cooler running motors would more completely combust the fuel. No clue what is right. I do know that gas has a low flash point and the hotter it gets the more vapor is created and therefore the more power you get out of each " drop" of it. By my reckoning the perfect scenario would be liquid O2 injected into compressed gas vapor....sounds sort of like a bomb. Anyway I digress...
I am sure all will be good with 87 and IF we have a cold winter I will add an additive to increase octane and improve combustion.