'11 GS A6. I recently had the water pump and t-stat replaced with OEM parts. I've also had a Dewitts rad installed back in the spring of 2018, and with the OEM 86C t-stat, any speeds above 80 regardless of ambient temps resulted in coolant temps of 90C (maybe 91C if I pushed it, or on a long uphill stretch). Backing off and coasting could drop the temps down to 87C. This was how it was running on the way to get the new pump and t-stat.
The first thing I noticed after the pump and t-stat was that highway temps are now 95 - 96C. Ambients were in the 10C range. The fan starts to ramp up at 95C, so that's running too hot. Essentially, the fan would always be on. I called the shop that did the work, and they thought that maybe there was still an air bubble, so I brought it back, and they put their vacuum system back on and did whatever they do to purge air bubbles, but there is no difference. They've got a new t-stat on order and are going to replace it. The shop is a dealership with a very good reputation, and I've had flawless work done there before.
I'm hoping that somehow the new t-stat that they installed was defective out of the box, and simply not in spec. I guess time will tell on that one.
Any other insights that the community has that could be causing the system to run hot? Could there still be an air bubble in the system? Could the new pump be defective?
The first thing I noticed after the pump and t-stat was that highway temps are now 95 - 96C. Ambients were in the 10C range. The fan starts to ramp up at 95C, so that's running too hot. Essentially, the fan would always be on. I called the shop that did the work, and they thought that maybe there was still an air bubble, so I brought it back, and they put their vacuum system back on and did whatever they do to purge air bubbles, but there is no difference. They've got a new t-stat on order and are going to replace it. The shop is a dealership with a very good reputation, and I've had flawless work done there before.
I'm hoping that somehow the new t-stat that they installed was defective out of the box, and simply not in spec. I guess time will tell on that one.
Any other insights that the community has that could be causing the system to run hot? Could there still be an air bubble in the system? Could the new pump be defective?
