My GrandAm GT keeps overheating. I have replaced the thermostat, water pump, coolant temp sensor, recovery cap, done a flush and fan switch relays. I can only get heat thru my vents at 240 degrees. My upper radiator hose gets hot and I pulled the new thermostat, put it in a pan and boiled it til it opened at 190. The 2 lines that run from the top of the recovery tank (I think they are air lines) we took those off and cleaned them out. The one that goes into the thermostat had like a foam material in it so we cleaned that up and the other one had a lot of grime in it. I also bled the air out of the system after I put everything back together. Please someone help, my car is making me go crazy!
1999 Grand Am Se 2.4L- We Checked The Relays And They Worked. Then We Checked All Fuses And They Were Good. But The Fans Still Dont Come On At 200 Degrees. When We Turn The AC On Both Fans Come On And Stay On After We Turn Off The AC Then When We Shut The Car Off They Dont Come Back On? And The Car Normally Runs At 180? Any Solutions?
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Re: 99 GrandAm GT v6 3.4L overheating
Can't give you a definite "fix" only because I'd need to do testing. But, two items you need to have checked are: 1. have a hydrocarbon test done fro the cooling system to verify that you do or don't have a head gasket problem. 2. have someone check the radiator with a "heat gun" to see if there are any cold spots. Home flush kits and sometimes even shop flush equipment will force cleaner around, not through heavily plugged areas and not clear the obstruction. Heat gun is best way of finding cold areas that are not flowing. also...you mentioned fan relays...does the fan come on?
If you have no heat at 240degrees and you know you have water. then you have air in your lines. these cars have major issues with dex cool older than about two years ago being corrosive when mixed with clorinated water. first thing to go is your manifold gasket then if not careful head gasket or cracked block. Take it to a shop and have them pressurize your engine cylinders with air to tell if anything is wrong. then have them get the air out of your coolant. the radiator sits lower than the maotor or heater core creating air locks in the lines. trust me have read hundreds of stories on line about this and had it happen to me.
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I think the first thing I would do is take the thermostat out and run the engine without it. If the engine stops running hot, try a 180 degree instead of the 195. As for the low coolant light, can you unplug the sensor and make the light go off ?
OVERHEATING CAN BE CAUSE BY MANY THINGS LIKE FAULTY THERMOSTAT AND FAULTY RADIATOR PRESSURE CAP,TOO MUCH WATER IN COOLANT SYSTEM NEED 50 / 50 WATER AND ANTIFREEZE.LOOK FOR WATER PUMP WEEP HOLE LEAK, IF COOLANT LEAKING OUT WEEP HOLE WATER PUMP BAD NEED REPLACING.CHECK FOR LOW COOLANT LEVEL, YOUR RADIATOR OVERFLOW JUG SHOULD HAVE COOLANT AT THE FULL COLD MARK IF NOT KEEP ADDING COOLANT INTO COOLANT OVERFLOW JUG UNTIL COOLANT STOP DROPPING AND FULL COLD MARK, IF OVERFLOW COOLANT JUG WAS EMPTY RADIATOR IS LOW ON COOLANT.WHICH CAUSE AIR IN COOLANT SYSTEM KEEPING THE ENGINE COOLANT TEMPERATURE SENSOR FROM BEING SUBMERGE IN HOT COOLANT WHICH TURN ON THE COOLANT FANS.WHEN ENGINE COOLANT TEMPERATURE GET CERTAIN SET TEMPERATURE LIKE 190 DEGREES THE PCM AND COOLANT SENSOR WILL TURN ON COOLANT FANS, IF VECHICLE OVERHEATING COOLANT FANS NOT WORKING EITHER YOU HAVE FAULTY ENGINE COOLANT TEMPERATURE SENSOR CHECK COOLANT FANS FUSE AND RELAYS. YOU CAN CODE SCAN CAR TO SEE IF YOU HAVE FAULTY PCM, FAULTY ENGINE COOLANT TEMPERATURE SENSOR OR FAULTY COOLANT FAN RELAY.IF COOLANT FAN AND ENGINE COOLANT TEMPERATURE SENSOR OKAY,YOU HAVE CORRECT COOLANT LEVEL IN COOLANT SYSTEM, THERMOSTAT AND RADIATOR PRESSURE CAP BEEN REPLACED, YOU COULD HAVE BLOWN HEAD GASKET CHECK ENGINE OIL LOOKS LIKE MILK SHAKE HEAD GASKET BLOWED ALSO WHEN HEAD GASKET BLOWED YOU CAN DRIVE CAR SHORT DISTANCE START OVERHEATING AND YOU LOOSE ENGINE POWER SUSPECT BLOWED HEAD GASKET.
I'd start with replacing thermostat (that's the most common fault) Other possibilities; waterpump,leaky hose, radiator cap (not holding pressure), fan belt broken. I'd inspect for belt & leaks - if good replace thermostat.
WELL YOU NEED TO DRAIN COOLANT LEVEL BELOW THERMOSTAT LEVEL.YOU HAVE TO DISCONNECT MAF SENSOR LOOSEN AIRDUCT 2 LARGE CLAMPS LOOSEN REMOVE 4 SCREWS TO AIR FILTER COVER LIFT UP REMOVE COVER. THEN REMOVE AIR FILTER AND HOUSING, FIRST DISCONNECT MAF SENSOR.YOU HAVE TO DISCONNECT THROTTLE CABLE AND SHIFT CABLE.YOU HAVE TO DISCONNECT REMOVE THROTTLE BODY COOLANT HOSES DISCONNECT IDLE SPEED CONTROL VALVE CONNECTOR AND DISCONNECT TPS SENSOR CONNECTOR. THEN REMOVE THROTTLE BODY ASSEMBLY. YOU NEED TO BUY NEW THROTTLE BODY COOLANT HOSES AND NEW THROTTLE BODY GASKET FOLLOW TOP COOLANT HOSE TO ENGINE BLOCK.NOW YOU SEE CAN AND REMOVE THE THERMOSTAT HOUSING REPLACE THE THERMOSTAT.BESURE TO HAVE EXTRA COOLANT ON HAND.BLEED COOLANT SYSTEM WHEN DONE.TO BLEED COOLANT SYSTEM REMOVE RADIATOR CAP ON OVERFLOW JUG.THEN OPEN BLEED SCREW ON THE WATER PUMP BYPASS HOSE PIPE JUST A LITTLE.POUR COOLANT IN THE OVERFLOW JUG UNTIL LEVEL STOP DROPPING.STOP AT COLD MARK ON JUG.CLOSE BLEEDER SCREW ON WATER PUMP BYPASS HOSE PIPE.CRANK VECHICLE CHECK FOR LEAKS. START UP ENGINE LET IDLE FEW MINUTES THEN CHECK COOLANT LEVEL ADD MORE UNTIL UNTIL LEVEL STOP DROPPING.PUT RADIATOR CAP BACK ON OVERFLOW RESERVOIR. LET ENGINE IDLE WATCH COOLANT TEMPERATURE GAUGE.WHEN GAUGE START CLIMBING. TURN OFF ENGINE WAIT FEW MINUTES TAKE A LARGE RAG OPEN RADIATOR JUST A LITTLE YOU HEAR HISS NOISE.WHEN PRESSURE STABILIZE DONT GET SCALDED BECAREFUL.OPEN CAP LITTLE MORE.IF COOLANT PRESSURE STILL BOILS OUT WAIT 20 MINUTES ADD MORE COOLANT TO RADIATOR OVER FLOW WHEN COOLANT LEVEL STOP DROPPING.PUT RADIATOR CAP BACK ON START VECHICLE UP LET IDLE UNTIL THERMOSTAT OPEN. THEN FEEL TOP RADIATOR HOSE FEELS HOT THERMOSTAT OPEN WATCH TEMPERATURE GAUGE.IF GAUGE TEMP START CLIMBING TURN OFF ENGINE WAIT A WHILE.CHECK AND ADD MORE COOLANT.WHEN THE ENGINE CAN IDLE TEMP GAUGE STOP CLIMBING YOU HAVE BLEED COOLANT SYSTEM.KEEP CHECK ON COOLANT LEVEL.
Replacing the temp sensor will not keep the vehicle from overheating. There is another reason why it is overheating. Most common problem is a bad thermostat. Next most common is the water pump. Another common problem is low coolant. I would suggest check you coolant first. It is the easiest, and cheapest. Then the thermostat. It is more than likely one of these two.
The best way to flush it would be to take off the bottom radiator hose and pump water through the fill nozzle after all the coolent is out you can then hook the hose back up and replace it with new coolant.