2001 caddilac new water pump , thermostat , getting heat from heater core , but my 2001 cadillac dts seems to heat up faster than it should

plugged radiator, bad radiator fan, blown head gasket

Replace radiator water by adding coolant

my 98 Blazer I had to replace radiator water pump heatercore and hoses. Had head gasket go. Once that happens air and dexcool corrode cooling system. Do you smell antifreeze? Are you loosing antifreeze? Check oil see if its another color not clear or black but i think light brown. Have you flushed out system?

Do a compession check. Sounds like combustion problem. Possible running to lean also that can cause them to overheat

Feel the 2 tubes at the firewall for the heater core. If they are not getting hot, the heater core needs to be flushed out or replaced. I had this problem with a 1990 Cadilac Deville, it was just a plugged up heater core.

Remember to install sealant after flushing out the system to prevent leaks.

flush your system the heater core may be clogged hope this helps

are both heater hoses hot if so either you have a blend door problem or you have air trapped in the heater core

do the heater core coolant supply hoses both get hot at the firewall in the engine compartment? if yes then you have a defective temperature control blend door actuater motor.

Reverse flush the cooling system and put in fresh antifreeze to -20. (20 below zero). If that doesn't help, replace the thermostat.

a bad heater core will just leak. it could leak alot. do you ever smell antifreeze? check the coolant level. it can get pretty low before it will overheat. the thermostat should be ok but there could be corrosion. when you had the water pump replaced was the cooling system flushed? 2001, its probably due for a flush. what coolant does it take? (green or orange)