overheating please help 99 montana

i have a 99 pontiac montana van and it is overheating like crazy i replaced the t-stat , water pump, hoses, new raidator cap, flush the radiator the low coolant light stays on the hoses are tight and there is no heat when the heater is on full power please someone help please

is it actually overheating or is a sensor giving false info?

Sounds like you gota clogged motor. By this I mean your radiator may be clogged due to intake gasket leaking oil into your radiator, or the coolant passageways in the motor could be clogged up so much that the motor cannot remain cool because of poor circulation. This often times cloggs up the heater core too with crystalized dex-cool. Dex cool crystalizes when exposed to air in the system, usually as a result of intake gasket failure. Even if the gasket has been replaced and is no longer leaking, you may have to replace your heater core and try and get the motor chemically flushed multiple times to remove the cloggs.
Good luck

did you bleed the air out of the cooling system? If you don't, air pockets get trapped in the intake and heater core and will cause overheating and no heat output from the heater core

We own a 99 Montana, going through the exact same thing. Blowing cold air and overheating. Replaced T-stat, water pump, intake manifold gasket, etc. Going in AGAIN tomorrow for more repairs. They found combustion in cooling system and they will be replacing the cylinder gaskets and or pistons. Then to top it off the lifters are knocking, another repair. We are extremely disappointed in van, extras on van are great, but mechanically disappointing. All I can say is thank goodness we purchased extended warranty. Good Luck

Got the van back today, the head gasket was leaking and causing combustion in cooling system, in turn was causing air pockets. Problem fixed. They used a dye in the radiator to determine the leak. WARNING make sure to have code for anti theft radio before repairs are done. Look up in manual and set your code and REMEMBER it. Good Luck

We have a 99 Montana and it was heating. Had the radiator flushed and it took care of the problem.