Heater core seems to be leaking

[Derrick Filas]

I have a Dodge Durango 2001 4.7 litter. I recently had an issue with my radiator. I went to add water to my radiator and I noticed a thick-milkshake type coolant in it. I was told that my radiator had a leek in it and the transmission fluid was slowly keeling into it. The fluids always seemed fine but I had to continuously add small amounts of oil to the car. The mechanic changed the radiator and there was still the a little bit of the milkshake in the radiator.

Now my car is showing signs of a bad heater core. There is smoke coming through the vents when the heater is on with defroster button pressed in. Plus the car leaks fluid under the car towards the rear of the engine on the passenger side. I am not sure if it is leaking in the car. This is only when the heater is on.

Please advise, I’m hoping that it might be a hose or a cloth somewhere. The heater does get hot. Do you think I might not have to change the heater core? I’m a novice at car repairs.

Topic

[Ian]

I think your best tool for diagnosing whether or not you have a heater core leak is gonna be the fluids leaking from the vehicle. I can see a couple of possibilities here-

1. Fluid leaking from passenger side INTERIOR of vehicle. Fluid has sweet smell/taste. (or bitter taste. I have seen Chrysler-specific embittered coolant in the past.) Suspect faulty heater core or line.

2. Fluid leaking from passenger side INTERIOR of vehicle. Fluid has no specific smell or taste. Suspect clogged air-conditioning evaporator drain or line. This is water condensing on the evaporator. Normally, this water would drain out somewhere in the passenger side engine bay area, but if the drain becomes clogged, it can overflow and drain out in the interior of the vehicle.

3. Fluid leaking from EXTERIOR passenger side engine bay area. Fluid has no specific smell or taste. Suspect a normal condition. Water condensing on a cold air-conditioning line, the air-conditioning expansion valve, or draining from the condenser.

4. Fluid leaking from EXTERIOR passenger side engine bay area. Fluid is NOT water (DOES have specific smell, taste, color, etc.) Suspect other fluid leak. With the way most Chrysler vehicles are set up. (I have a similar vehicle, 2000 Dakota 4.7, manual) I would suspect an engine oil leak or a leaking transmission line.

[Author]

Replies