I have a Pontiac Montana and we have replaced the radiator, water pump, and the thermostat. Because the car was running hot...we first replace the radiator and thought..problem solved...it wasn't running hot any more..well about a week later it started again. So we were told that it must need a new water pump so we replaced it. It also done well for about a week or so then it started running hot yet AGAIN!! So then we were told it must the the thermostat. And it done the SAME THING AGAIN!! PLEASE any ideas??

SOURCE: replace thermostat 2003 pontiac montana

yes but with the right shaped wrenches and tiny hands it can be done without removing the exhaust crossover pipe

SOURCE: Temperature gauge shows hot

head gasket does the overflow bootle have bubbles in it when idleing warm if does most likey rear head gasket.

SOURCE: car runs hot

CHECK YOUR RELAY IN YOUR FUSE BOX UNDER THE HOOD ON THE DRIVERS SIDE INNER FENDER. THE A/C AND THE HEATER RELAY ARE SAME. CHECK AND SEE IF THE A/C REALY WORKS BY TURNING ON YOUR A/C SWITCH. THE ELECTRIC FAN SHOULD START RIGHT AWAY. OTHERWISE YOU HAVE TO WAIT TILL THE ENGINE ACHEIVES OPERATING TEMP TO KICK THE FAN ON. IF ONE DON'T WORK AND OTHER OTHER DOES... SWITCH THE RELAY AND SEE IF IT WORKS. BEEN THERE AND DONE THAT. $9.00 FOR A NEW RELAY AT CHECKER AUTO PARTS.

SOURCE: need to replace thermostat on pontiac montana van.

public library...Chilton or Haynes auto repair manuals or collisionrepairadvice.com     make sure you bleed the system

SOURCE: after spending 880 dollors on having a head gasket

YOU COULD HAVE A DEFECTIVE WATER PUMP OR THERMOSTAT ALSO RADIATOR PRESSURE CAP.MAKE SURE YOUR WATER PUMP IS BEING TURNED BY DRIVE BELT.NOT SLIPPING.MAKE SURE COOLANT SYSTEM HAS BEEN BLED AND YOU HAVE HALF ANTIFREEZE HALF WATER.CHECK YOUR CRANKCASE WHEN CAR COOLS DOWN.IF OIL STILL LOOK LIKE MILK SHAKE.YOUR NEW HEAD GASKETS LEAKING.THE MECHANIC WHO REPLACED HEAD GASKET DIDNT DECK THE HEADS.THEY PROBABLY NEED SHAVED A LITTLE SO HEAD GASKET WILL SEAL.