NO HEAT How to Fix
#1
12-15-2013, 02:53 PM
NO HEAT How to Fix
This is just one way to resolve a no heat / low heat issue I had in my 3.9 Dakota.
Before I got the truck someone must have put some block sealer in the coolant system. It worked too good because it half closed the heater core. With the engine at operating temp, heater controls turned on as hot as possible and fan on high. I get lukewarm air at best. The fix posted below might not work for you and you could mess up your heater core so proceed at your own risk. But I'm just reporting it does work. Be careful use safety goggles, rubber gloves, ect. Remember above all else YOU ARE RESPONSIBLE FOR YOUR SAFETY IF IT LOOKS OR SOUND DANGEROUS IT PROBABLY IS.
First
I removed the thermostat and replaced the goose neck back on the engine. Remember a motor run on electricity.
Second
1. Disconnect the heater core hoses FROM THE ENGINE not the heater core itself. That makes it a lot easier for the next step.
2. Mix some CLR or Lime-away in a gallon jug. I mixed one bottle Lime-away per gallon of water.
3. I used my mouth to blow (Lets try to be adults here) the fluid out of the heater core by blowing on one hose and catching the fluid coming out of the other hose to be recycled. You could use an air compressor but be careful. Too much pressure could blow the welds on the heater core apart. NOT A GOOD THING.
4. Use a funnel and pour the lime-away mix in one hose until it starts to drip out of the other hose. Then place both hoses high above the heater core as possible and let the mixture work for 10 to 15 minutes. Blow out the mixture, catching it in a container for proper disposal. Then repeat. Keep doing this until the mixture is gone. You may have to mix 2 or more gallons or repeat the process in a week or two. You could pour the mix you caught back in if you wish to keep from mixing more from fresh.
Third
Once complete with the lime-away mix. I recommend running plain water (bout 2 to 50 gallons your call) through the heater core to make sure all the lime-away is out of the heater core or diluted plenty. Place the heater hoses back on the engine in the proper places. Now drain out some of the coolant. Catch it for recycling. Then add some coolant system flush to the coolant system. Follow the direction on the flush bottle. I used a 22oz bottle of Zerex Super Flush. BE CAREFUL FOLLOW DIRECTIONS OF FLUSH BOTTLE!
Fourth
Once the coolant flush process is complete. Place the correct thermostat and gasket back on the engine. Fill the coolant system and including the coolant overflow tank with the correct type of coolant. Get engine backup to operating temp and check for leaks and heat. If all goes well you should have great heat and no leaks. Best of luck.
Kilgore
Before I got the truck someone must have put some block sealer in the coolant system. It worked too good because it half closed the heater core. With the engine at operating temp, heater controls turned on as hot as possible and fan on high. I get lukewarm air at best. The fix posted below might not work for you and you could mess up your heater core so proceed at your own risk. But I'm just reporting it does work. Be careful use safety goggles, rubber gloves, ect. Remember above all else YOU ARE RESPONSIBLE FOR YOUR SAFETY IF IT LOOKS OR SOUND DANGEROUS IT PROBABLY IS.
First
I removed the thermostat and replaced the goose neck back on the engine. Remember a motor run on electricity.
Second
1. Disconnect the heater core hoses FROM THE ENGINE not the heater core itself. That makes it a lot easier for the next step.
2. Mix some CLR or Lime-away in a gallon jug. I mixed one bottle Lime-away per gallon of water.
3. I used my mouth to blow (Lets try to be adults here) the fluid out of the heater core by blowing on one hose and catching the fluid coming out of the other hose to be recycled. You could use an air compressor but be careful. Too much pressure could blow the welds on the heater core apart. NOT A GOOD THING.
4. Use a funnel and pour the lime-away mix in one hose until it starts to drip out of the other hose. Then place both hoses high above the heater core as possible and let the mixture work for 10 to 15 minutes. Blow out the mixture, catching it in a container for proper disposal. Then repeat. Keep doing this until the mixture is gone. You may have to mix 2 or more gallons or repeat the process in a week or two. You could pour the mix you caught back in if you wish to keep from mixing more from fresh.
Third
Once complete with the lime-away mix. I recommend running plain water (bout 2 to 50 gallons your call) through the heater core to make sure all the lime-away is out of the heater core or diluted plenty. Place the heater hoses back on the engine in the proper places. Now drain out some of the coolant. Catch it for recycling. Then add some coolant system flush to the coolant system. Follow the direction on the flush bottle. I used a 22oz bottle of Zerex Super Flush. BE CAREFUL FOLLOW DIRECTIONS OF FLUSH BOTTLE!
Fourth
Once the coolant flush process is complete. Place the correct thermostat and gasket back on the engine. Fill the coolant system and including the coolant overflow tank with the correct type of coolant. Get engine backup to operating temp and check for leaks and heat. If all goes well you should have great heat and no leaks. Best of luck.
Kilgore
Last edited by KillerKilgore; 12-28-2013 at 05:29 PM.