Engine running hot displays on dash....cold air blowing thru vent
1995 cadillac sedan deville....radiator full.....coolant in reservoir tank...just replaced thermostat and flushed system 4 mos ago..right before it started blowing cold air I thought I smelled a faint burning odor and I heard a clicking noise that seemed to be coming from the firewall area behind the vent or radio. Coolant repeatedly leaks behind the reservoir tank but no one can find the leak.
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What is this cap on?? Radiator or windshield washer reservoir? Something else?
If the radiator, most newer cars have a plastic bottle or tank that has a "cold" and "hot" level indicated. You should be able to see the coolant level thru the tank. You should NOT need to open the radiator cap if your car has this tank. Add a 50/50 mixture of water and coolant (of a type your car requires) up to the "cold" mark and start the car. Let it run with the heater set to HOT and fan set to HIGH. Continue adding the 50/50 mixture to maintain the coolant level to the HOT level mark on the tank as needed with the engine running. Stop when there is HOT air blowing out of the heater.
If your car does NOT have this tank, you may only open the radiator directly when the engine is COLD. Wait several hours for the engine to cool after shutting off before attempting to remove the cap.
When cold, press DOWN on the cap WHILE turning. Most caps will come off after a 1/4 to a 1/2 turn. Start the engine and set heater HOT and fan to HIGH. Continue to add a 50/50 mixture of coolant to the radiator until the heater blows HOT air. The coolant level in the radiator should be just under (1" or less) from the bottom of the radiator opening.
Yes it would overheat without circulation, but the coolant doesn't circulate through the overflow tank. That reservoir only gets coolant into it when the coolant gets hot and expands and pushes the radiator cap seal up to let coolant into the reservoir. When the vehicle cools down, the coolant contracts and the lower level in the radiator will siphon the coolant out of the reservoir back into the radiator. Coolant circulation is from the engine to the radiator and back into the engine...and also through the heater core. You may have an air block in the heater core. Check by taking off the outlet hose at the firewall or at the engine and see if you have a slow steady stream of coolant, with the engine running and heater controls on high heat. If it was an air block, a steady stream should quickly start. If you get little or no flow, the core may be plugged and need flushing backward or replaced.
How do you know it gets hot? Are you going by the temperature gauge on the dash? Or have you checked under the hood and found out the engine really is running hot? ...Reason I ask is, something just doesn't sound right in your description. After just 5 minutes from starting and driving away, the engine would not yet be at normal operating temperature. That would explain the heater not yet warm. But the temp. gauge says hot? If so, I would replace the temperature sending unit on the engine. the one for the dash gauge, and see if that was the problem-not reading the temp. accurately. Couple of other things: Are you sure you got all the air out of the coolant system? Start the car with the radiator cap off and let it run until the engine is warmed up fully, then shut it off and install the cap. Does your reservoir tank stay about half full where it should be, between the full-hot and full-cold marks? If your problem persists. I would have the coolant system pressure tested, and see if you could get a true temperature reading of the coolant when it seems to be running hot. Good luck.
WAIT UNTIL YOUR ENGINE IS COLD,YOUR RADIATOR PRESSURE CAP IS LOCATED ON THE COOLANT OVER FLOW RESERVOIR, THATS WHERE YOU ADD COOLANT WHEN COOLANT LOW,YOU POUR COOLANT IN THE OVER FLOW RESERVOIR UNTIL COOLANT LEVEL REMAIN AT FULL COLD MARK DONT OVER FILL OVER FLOW RESERVOIR, WHEN COOLANT LEVEL STOP DROPPING WHEN ADDING COOLANT AND COOLANT LEVEL STAY AT COLD MARK ON THE RESERVOIR YOU RADIATOR HAS THE CORRECT COOLANT LEVEL IF COOLANT LEVEL KEEP DROPPING CHECK FOR COOLANT LEAKS AROUND RADIATOR AND THE TOP AND BOTTOM RADIATOR HOSES, LOOK FOR COOLANT LEAK AT WATER PUMP GASKET OR SEAL OR LEAK AT WATER PUMP WEEP HOLE IF YES REPLACE WATER PUMP.
FILL COOLANT SYSTEM UP BY POURING COOLANT IN THE EXPANSION TANK UNTIL COOLANT LEVEL STOP DROPPING IN THE EXPANSION.WHEN YOU POUR COOLANT IN EXPANSION TANK AIR BLEED OFF THROUGH THE SMALL COOLANT LINES GOING TO EXPANSION TANK.WITH PRESSURE CAP OFF RADIATOR COOLANT LEVEL IN EXPANSION IS AT FULL COLD MARK.WHAT YOU TO DO CRANK ENGINE UP LET IDLE WARM UP UNTIL COOLANT DROPS IN EXPANSION TANK KEEP ADDING COOLANT UNTIL STOP DROPPING STAY AT FULL COLD MARK.WHEN COOLANT LEVEL START RISING IN EXPANSION TANK.PUT PRESSURE CAP BACK ON RADIATOR.WHILE ENGINE IDLING WATCH TEMPERATURE GAUGE.IF START CLIMBING TURN OFF ENGINE LET IT SIT FOR LITTLE WHILE TAKE A LARGE RAG OPEN RADIATOR PRESSURE CAP A LITTLE AT A TIME TO KEEP FROM GETTING SCALDING TO RELEASE AIR IN COOLANT SYSTEM.WHEN PRESSURE IS RELEASED OPEN PRESSURE CAP ADD MORE COOLANT IN THE EXPANSION TANK.CRANK ENGINE AGAIN LET IDLE WHEN TEMPERATURE GAUGE START CLIMBING. TURN OFF ENGINE WAIT FOR WHILE BEFORE OPEN RADIATOR PRESSURE CAP.WHEN YOUR THERMOSTAT OPENS WHEN TOP RADIATOR HOSE IS HOT AND ENGINE COOLANT TEMPERATURE GAUGE STOP CLIMBING AND COOLANT LEVEL STOP DROPPING IN THE EXPANSION TANK.ALL AIR IS EXPELLED FROM COOLANT SYSTEM TO KEEP ENGINE FROM OVERHEATING.
Hello: The first thing is check the coolant level. Do this on a cold engine, if engine is a 4.9 check both the radiator and the overflow tank. Make sure they are full of coolant. If it is a Northstar engine then make sure the surge tank is full, this may require checking the tank again after bring the engine to operating temperature then let it cool off. DO NOT OPEN COOLING SYSTEM ON HOT ENGINE it could cause serious burns to you.
Add a mixture of one-half water and one-half antifreeze to the radiator. Fill it right up to the top.
Fill the overflow/coolant reservoir with the same 50/50 mixture.
Leave the radiator cap off, turn the engine on and let it run until the radiator "burps": You will see the coolant level drop and may see or hear a large air bubble come to the top as the system burps.
Keep an eye on the temperature gauge throughout this process.
Refill the radiator to the top and coolant reservoir as needed.
Put the radiator cap back on.
You might have some air inside coolant system, try follow the steps that i just created. if its not work out please relay me back thanks
The most common overheating problem with the Northstar engine is a blocked purge line(small hose).The purge line is designed to purge air out of the cooling system. There is a small diameter hose coming from near the top of the coolant tank (not the cap) ,this is the purge line. With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating. If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage. The hose goes in to the engine to a crossover and comes out the other side close to the thermostat housing,the blockage may be there.
there are no reset codes, did you bleed the air out of the cooling system? if not do this procedure, if that doeasn't fix it u have a failed air temperasture control blend door motor actuator. The generic method of bleeding air from the cooling system is to use a floor jack and raise the front of the car as high as poss, then fill the coolant recovery tank full and run the engine until it just starts to overheat, high end of normal zone on gauge, then shut the engine down and run cold water over the radiator core, this will self bleed the system and the coolant will be pulled from the recovery tank, repeat as necessary, never let the recovery tank run dry or more air will be pulled into the cooling systeml ,
If the blower was working why did you replace it?
Heat is made by the engine, and then it is sent into the heater core and a fan, blower motor, blows heat into the car.
First - check that the coolant level is full. If not add MIXED coolant.
Then drive a few miles for the engine to get hot.
If coolant level is full, the thermostat might be bad, or the heater core might be plugged.