So its in the 60s & 70s here recently. I've noticed that my 2.8 quattro's water temp gauge is taking a LONG time (>10 miles at least!) to come up to even a quarter way up on the temp gauge, and the oil temp is also running quite low. If I drive it long enough it usually does come up to center on the water temp, so I can't believe its a stuck open thermostat...

I doubt both gauges would be bad simultaneously (or would they?) and have never had a car run this cold before. All I can think of is that the engine is frictionless! LOL Maybe thats why it runs so good for 215K miles.

Any thoughts?

 

Sounds like a thermostat to me..

 

My 2.8 took forever to warm up, and it's been through 3 thermostats. If it makes it to the middle and stays there your thermostat's probably fine, though it could just be slow to close.

 

Could also be worthwhile to replace the coolant temp sensor.

 

Start with the coolant temp sensor because it is cheap and much easier to replace than the thermostat.

I had similar symptoms as you describe and did the temp sensor first with no improvement. At that point I knew it was the t-stat. The timing belt had just been done by the PO, but the t-stat was not replaced at the same time. It was a real pleasure tearing it down to the belt just to replace the t-stat.

Make sure to get OEM and a replacement o-ring if you do replace it. Also, if you are anywhere close to needing a timing belt, you might as well just do that at the same time as you have to do all of the same labor.