Yesterday morning, I got a "groaning" sound right when I turned on the defroster in the car. I've gotten this before when turning on the fan (vent) but it doesn't happen every time. It's happened maybe 4 times in the past 2 weeks (but I don't use the fan/defroster very often either). Anyone know anything about this?

 

Is it the heater fan making the noise? starts out slow and then gets quiet as it blows the air?

The fan in my old work van has been doing that for years. it's worst when it hasn't been used for awhile. If it's turned on everyday - it works fine. I think it's where the fan motor is getting worn out. Mine hasn't quit yet so I haven't bothered to replace it

 

one of two things:

fan motor, as marksr suggested

vacuum motor for one of the dampers

I have heard both make noise that might be described as a groan by some.

 

Yep, sounds like the blower motor.
If you can get to without too much hassle spray some WD-40 on the shaft.

 

Not sure if it happens when it is heating or cooling. But it's not the fan that cools the engine. As you have described it, groaning starts fast and tapers to quiet, and it happens when the fan hasn't been used in a while. This car is actually only 2 weeks old. I assume it's going to get worse with time so maybe I will wait for it because the dealer says if they can't reproduce the sound, they won't replace it. I have 5 years on the warranty.

 

The heat and ac use the same fan and ductwork. This fan isn't the one that is attached to the radiator. It's under the dash in the neighborhood of the firewall where the heater core is mounted.

It certainly shouldn't make a noise on a new car. If you are convince it makes the noise everytime it's turned on after not being used for several days, I'd leave the fan off [no heat or ac ] for a few days and then take it to the dealer and let them turn the fan on for the first time.

 

since this is a new car, I would tend to think it is a vacuum motor or damper groaning rather than the blower motor. I don't think I have ever seen a bad blower motor from the manuf but I have heard many dampers or vacuum motors make groaning type noises.



try this out:

when you turn the defrost or whatever makes it make this noise on, try it with the fan on high. then after whatever time it takes in between being able to make the noise, turn on the defrost or whatever but have the fan on low.

If the noise is basically the same, I would tend to say damper of vacuum motor.

If you get a really distinct difference in the sound, then I would look at the fan closer.


I have seen leaves or other foreign material in a fan, especially if it is a new car. Small animals like areas like that and are known to make homes in the fan area, even filling them with acorns. Since new cars can sit untouched for months at a time, it happens. It appears that squirrels and ground squirrels like that new car smell as well.

 

Maybe it is just the car breaking in? The brakes are also making a noise (a faint clank underneath the car when I press or release the brake) but it is also very intermittent and I can't reproduce if asked. I'm thinking of just waiting until my first service check. Either it's going to get consistent or go away by then.

Also, Volvo has a TSB TO REDUCE THE CURRENT THROUGH THE VACUUM SWITCH FOR THE BRAKE VACUUM PUMP.