A few days ago, I took a short trip, and 30 miles into the trip, the vent system started blowing hot for about 5 minutes, then went back to normal. It was a nice day, and I was running 70 mph with top up, no a/c, and the heat control way to the left. 2008 Redline, stock, 64k miles. No unusual temperatures, no puddles when I parked, and no apparent loss of coolant. Is this a warning of the dreaded water pump failure?

No, probably nothing to do with water pump (unless by extreme coincidence).

It's possible that the hot/cold air flap actuator is going out in the heater box in the cabin, under the dash. You can get the actuators quite cheaply and then it's a fairly simple DIY if you are reasonably flexible

However, I'd wait to see if it does it again, before you start buying parts or scheduling a mechanic.

Thanks! I'm not panicking, it hasn't happened since.

After 13 years of that stupid actuator that never worked...I finally changed it this summer..now I have temperature control for my air conditioner....u tube has the complete uninstall/install of the actuator....the trick to this...have small hands. LOL

This old fart isn't very flexible, and my hands aren't that small, lol.

Find a good woman who knows how to bend and use a SCREW driver....

Leaves my wife out - she's in a cast.

Very funny

So glad to hear this is a doable job. Mine has been going out for a couple years. Still works but wont change from cold to hot sometimes like its supposed to. also now makes a popping sound about 5 times in steady succession when I switch it to hot sometimes.

Definitely time to fix it.

Go to UTUBE and watch the video...till the end. The end is important in order to get to the 3rd DAMN screw. The instruction video is on a Solstice. Identical to us.