Dodge truck cab noise...Help!

[MorePwr]

Buddy of mine purchased a used Dodge crew cab, 4x4, hemi a few weeks back. 2006 model I think? He's been experiencing a lot of freeway speed rumbling/humming noise. loud I guess, he compared it to riding inside a bass drum apparently this is a common problem as it is mentioned it in his glovebox manual. the manual says to crack the back window a bit to stop the noise, which works, but now he can't hear the people talking in the back seat over the wind noise.

the questions are; is there a fix for this, other than rolling down the windows. and what's causing it?

thanks. Aaron

[Chatt69chgr]

I have a 2005 Dodge Quad Cab with Hemi 4X4.  I notice this only when I lower the front windows a little at highway speed.  But otherwise, it doesn't do it and is real quiet.  I think pressurized air enters the cab and having no way to escape alternately builds up and releases air pressure through the same window thus causing the sound.  It seems to be most noticable when the window is slightly cracked.  I usually just leave the windows up.  The cab is a sealed unit unlike a car where the air pressure can escape behind the back seat and thru the trunk.  I will admit that I never noticed this in my old Ford F100 regular cab.  Seems to be a characteristic of the particular volume of the Dodge Quad Cab.  Only thing I can think of is to put a check valve of some kind in the floor behind the seats for a pressure release mechanism. 

Since we are talking about Dodge Rams I ran into something the other day that I had not realized.  Whenever you set the HVAC system to defrost, the compressor runs.  And it doesn't matter whether the ac switch is depressed or not.  This might be something to remember since the compressor puts a drag on the engine and would, thus, reduce gas milage.  I don't like this feature but have not determined if it can be disabled or not.  I do realize that the compressor running will quickly defog the window but sometimes I don't want it to run and I want to be the one that decides if it does or not.

[pettyfan43]

The only time I get that sound in my 04 1500 is if I roll the BACK windows down. If just the fronts are down, I don't get that at all. BUT I have Ventshades that may deflect the wind away form the doors some. I don't remember hearing it before I put the ventshades on either. My truck doesn't have a sliding rear window though.

But I rarely ever put the back door glass down anyway though.

[rt green]

your compressor is designed to run when the defrost is on to keep it from locking up from non use in the winter. hate to replace a compressor every year

[rt green]

come to think of it, our company just bought a 97 one ton flat bed gmc truck. it has two plastic box type vents about half way down the back side of the cab. maybe this is gmc's solution

[Plumcrazy]

Since we are talking about Dodge Rams I ran into something the other day that I had not realized.  Whenever you set the HVAC system to defrost, the compressor runs.  And it doesn't matter whether the ac switch is depressed or not.  This might be something to remember since the compressor puts a drag on the engine and would, thus, reduce gas milage. 

Thats nothing new or unique, Chrysler has been doing that as far back as I can remember.   It's a good idea to run the compressor occasionally to circulate the oil.