over heating

[REB]

I am the proud owner of an 07 GMC sierra classic, I bought it new and have put 105,000 miles on it. On my most recent trip I put the winter cover over the grill, the temp was 10 above. As I was pulling a pretty good hill 7% grade, and it heated up, I stopped and removed the cover and the temp gage went right down. A week later I again put the cover on for a ski trip as the temp was 3 above. I again had a pass to go over, and about half way up it again heated up. Any thought out there as it has never done this before.

[gary_lucas]

I'm definitely not overly knowledgeable on this.

But I had similar issues last summer.

In addition the water cooler started leaking, it was end of season so I didn't do much with it, just loosened the cap a little and let it mostly sit over the next few months.

We just pulled the pump out, and found that the pump base was wearing out and probably wasn't running very efficiently.

The other thing to check is you're cooling stack? Is there a pile of mud and wasp nests hanging out in your radiator?

Anyway, hope it's not your pump... It's allot of labour to get to it.

G

[Kennedy]

How hot is it getting and how heavy are you pulling?

[More Power]

A few Februarys ago I towed a 6-8k enclosed trailer a about 500 miles that included some mountain passes. I noticed early on that even though it was pretty cool outside, I needed to remove the grille cover. Never overheated, but ran a lot warmer than normal... even with temps in the 10s.

Don't think it would overheat when running solo, but we shouldn't tow in the winter with the grille cover...