Has a bad odor when the fan is blowing

RENSEL

MEMBER
2001 DODGE RAM
V8
2WD
AUTOMATIC
97,500 MILES

My 2001 Dodge Ram has a bad odor when the fan is blowing. It doesn't matter if the AC, fan or heater is on, all three produce the odor (heat being the worst). I can get rid of it temporarily by spraying air freshioner in the intake vents. I am assuming that some mold or mildew has grown somewhere in the ventilation system but how do I locate it and eliminate it? What can be done to prvent it from returning?

Tuesday, September 22nd, 2009 AT 7:01 AM

3 Replies

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Chances are you have a heater core leaking. It can be a very small leak but the smell of hot coolant will produce a dead fish smell. Have you had to add coolant lately? Is the carpet wet on the passanger side?

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Friday, April 23rd, 2021 AT 11:04 AM

RENSEL

MEMBER
2 POSTS

I haven't had to add any coolant and no leaks on the passenger side that I am aware of. However I did flush the system about a week ago because it hadn't been done for a few years and now the odor is almost gone. Do you think this is just temporary? Is there any way to test the heater core theory without tearing apart my dash?

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Friday, April 23rd, 2021 AT 11:04 AM

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Chances are you got coolant on something and it is slowly going away. As far as the heater core, you will smell it when you run the heater. Also, they will usually leak into the passanger side of the car. THe carpet will get wet with coolant.

If it is going away, it is most likely from the flush you did. Lets see if it stops. However, make sure the coolant is full.

Let me know what you find.

Joe

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Friday, April 23rd, 2021 AT 11:04 AM