just what would/could cause the temp gage to go up on a trip where there is constant cooling air going thru,if I normally sat at 1/2?
I have driven 6 hrs almost nonstop in july and never saw the gage budge from its steady 1/2- position.
it seems like the cat could cause it if it was partly plugged over time.

if a gage drifts around,something is causing it. it may not be precise but I don't see the gage drifting on its own.

 

Over time all sorts of crap (dirt, bugs, mud, sticks, leafs, etc.) gets lodged in the radiator fins, especially down low. That reduces the cooling area across the radiator.
Give the rad a good spray cleaning to dislodge that junk and it may go back to holding a steady temp.

 

You can get a $15 or so bluetooth OBDII adapter on ebay, download a free OBDII app for Android (maybe Apple) and see the actual temp the computer sees.

 

Well Cadillac dropped off the Hummer today...

$8800.00 for the new engine, cat and some AC work that was damaged from the rough running engine..I questioned this but hell if you are droping $7500 whats another $300.

I had to buy a new Intake since the cylinder failure also burnt a small hole in it and it did not come with the new engine along with a Water Pump and Thermostate, Serpentine belt...

Runs GREAT!!!

I still would have liked GM to at least knock off the head replacement offer money to go toward the replacement

GM actually called me a few day back to answer survey questions on my experiance...

 

I have never done a total rebuild but I have priced the cost of doing it. Ive done long blocks rebuilt by rebuilders. but for a h3 3.7 I would pick a good running junkyard engine (factoty built!) for $2500 and pocket the change for gas. wow,$7500 huh.

 

This was in an H3 Alpha Hummer with the 5.3L vortec V8 engine was $3700 from GM.
30 hours labor at $110 Plus all the little extras and convertor.

 

I'm speechless...Wow!

Chris