'97 monte w/ 3.1 and coolant issues
 

Okay, I searched and didn't find what I am looking for. My temp gauge will go above normal then come back down. But if I have my heater on when the needle goes up it will still be blowing cool air and then it will warm up when the needle comes down. The oil looks good but I took it to a shop that said I need to replace an intake gasket. But if it's not in the oil or on the ground, where is it? Can it leak into the intake and the catylitic converter is burning up the smoke? WTF???

thanks for any help

RE: '97 monte w/ 3.1 and coolant issues
 

if your lower intake manifold is leaking, you could be getting coolent flowing into your intake and burning in the engine. i would also check the radiator, i had a small crack in mine near the upper retrun that i fixed with jb weld. it was so small that you would never see coolent on the ground but i would leak enough to notice.

RE: '97 monte w/ 3.1 and coolant issues
 

the 3100s are great for having intake manifold leaks and bad water pumps.

RE: '97 monte w/ 3.1 and coolant issues
 

Yep, my 97 Monte had both. Bad intake gasket and water pump failure. My coolant was leaking into the oil. In addition, belt tensioner went out. Not unusual for these engines. Still a good engine though.