Hello, Im new here to the forum. I have a 2001 Monte Carlo LS 3.4. The car has just over 180K and still runs smooth. Recently, I've been having a problem with the car losing coolant. I am at a complete loss.. There is no coolant whatsoever in the crankcase, ZERO white smoke, and I have a brand new driveway with no coolant drips. I've read that the intake gaskets go bad in this motor quite frequently. Also, there is always air in the cooling system.. I'm not sure where to start.. Intake gaskets, head gaskets, or something as simple as a thermostat?? Any help would be greatly appreciated!!

 

If you are losing the coolant, but don't see it on the driveway, my first suspect would be the head-gasket.

Can you rent a pressure tester and test the system?

 

using a powerful flashlight, inspect the engines intake gaskets areas after warming the engine to operating temperature. Mine was leaking but would cook off before hitting the ground. I'm losing coolant again and suspect that is the problem for the second time but I haven't checked. like yours, The car runs fine.

 

I've changed head gaskets on a few cars that I had in the past, but they all had either heavy white smoke from the exhaust or the milky looking oil. A friend of mine is a mechanic at a Chevy dealer, and when I told him that mine doesn't leak form the intake he said "oh trust me, it's leaking" lol. I'll test the pressure and really check out the upper and lower intake. Thanks for the help!!