I just had the radiator fluid for my 2004 G35 coupe replaced. Since then, it seems like the fan for AC and heat isn't blowing as hard as it used to. For example, the fan has 5 settings. At the lowest setting, you can barely feel any heat coming from the vents (they are definitely open), and the air is still hot. If you switch over to AC and kick the temp down to 60, it feels like the fans blow a little bit harder, but still not as hard as they used to.

Any ideas what might be going on?

 

maybe outside temps have something to do with this?

Where you located? Ambient temperature?

 

I'm in virginia, so it's not too cold. I've also had the car for 3 years, and haven't noticed any changes in fan speeds based on outside temperatures. I'd like to think it has something to do with the coolant flush, but I'm pretty sure there are no air pockets - and the engine still maintains a constant temperature.

 

strange that you noticed after the flush. got me on this 1
keep us posted

 

I haven't noticed anything "electrically" different, but I do know that it is really hard to get the fluid topped up after a total flush. Check the coolant daily until you don't need to add any more. The G is smart enough to keep all the coolant for the engine if there isn't enough in there to cool the engine and heat the cabin.

 

When was the last time that you change the cabin filter?

 

I don't recall ever changing the cabin filter - do you think that would affect the speed of the fans?

 

A filthy cabin filter, and we have all seen pics of really clogged ones, will not necessarily affect the speed of the fan. However, if the path of travel is impeded, there is much less air to distribute. The fan can only supply what it receives.

 

maybe it's the same thing, but it just sounds "faster" because its on recirculate when the AC kicks in?

 

the cabin filter will not affect the system to where its that noticeable on speed

 

I'm not gauging the speed based on how fast the fan "sounds" per se.

If I have the heat on with 1/5 fan speed, I can barely feel anything coming out of the vent, although it is still just as hot as you'd expect. When I crank the fan up to 5/5, I can definitely hear the fans blasting, and I can definitely feel as much air as you'd expect on the high setting. It's just the lower settings where you can't feel that air, like 1 and 2.

Hmm, now that I just typed that out.. maybe it is the filter, considering air would be easier to "block" with the filter at the lower fan speed.

Is there any way that the changing of the radiator fluid could have impacted this?

 

Not that I can see.

 

my understanding is that the won't run at it's full setting until it has reached a certain temperature. For example...if you set your temp for 72 and turn on the heat to fan speed 2 it will flow air into the cabin but at a lower speed until the temp of the air is near 72. This is to prevent cold air from blowing on you when you want heat. Same for the AC on a hot day it will wait until the air has cooled to a temperature before blowing air at your set speed and temp. Just my observations.