Good news and bad news:
Good: The transmission cooler worked great. Highest temp of the trip was 190 but normally stayed in the 170's.
Bad: Only made it about 20 miles before the engine light came on and the noise started.
Truck is at the GM dealership now. Hopefully they can figure it out.
To the denali owners. What oil pressure are you running while towing 2500-3000 rpm's? I'm only running about 25. I don't feel like that is enough. Thats my only explanation for the noise and oil temp. I know the oil is hot because that is the first thing I check when it starts making noise. It smokes a little out of the dip stick hole when i check it.
