2nd Gen Non-Engine/Transmission Cab Noise Mystery

[MFrenchek]

I've read most all of the previous noise posts and will be using some of the methods to improve things, but how my cab became noisier is the mystery. I've had the truck since new and have only 91,000 mile on it (just broke in). It has been relatively quiet until recently. I notice a gradual increase in the clatter factor and turbo sounds over a few days. I not only have the traditional whine but can clearly hear the distintive whooshing sound as this baby sucks air. Again this is recent and now sounds like a hole has been opened into the engine compartment behind the dash. A question of those who have removed their dashes. Is there sound deading material against the firewall on the inside that may have come off? Everything seems to be inplace under the hood. There has been a change SOMEWHERE. While we all love the distinctive sounds our trucks make, too much of the good stuff can be bad. Any help and advice would be appreciated. I've got my interior out to do some sound work so now is the time to tackle this. I am completely baffeled on this one. Thanks!!

 

[SRath]

Just a shot in the dark: Check your shifter boots for tears; inner and outer. They aren't too far from that turbo. Check your door weatherstripping, too. Mine looks good, but isn't, and my bodyshop buddy tells me these Dodges are terrible for poor door sealing, especially as the rubber ages and gets flattened. Mine drives me nuts when the wind is just right, so I believe him. You would be surprised how much noise those rubber items can let in if they aren't near-perfect. Your signature says you have a BHAF, but does it still draw air from the fender? If so, and if that passenger door weatherstripping is getting bad, that might be a source of the sound you describe. Good luck!

 

[Allnew2Me]

If you open the hood and look down where the hinges are you will see a piece of foam that is intended to be placed between the outer sheet metal and the firewall on both sides of the truck. Sometimes they are loose and not tightly placed, mine were both sideways. You can reach down and turn them to the proper orientation and put them back where they go, this might be part of what you have heard change.

 

[BeefDoc]

I recently purchased a 94 with 225K on it that had tremendous cab noise. It sounded like the engine was going to come right into the front seat with me. After driving it a few days I found the problem, a small hole in the rubber transfer case boot. All of the engine noise was following the bell housing and transmission right into the cab.



FWIW



Matt

 

[MFrenchek]

Thanks guys. I checked everything you mentioned and all is in good order. Not sure about the door gaskets. My old Ramcharger had the same issue with the gaskets. The noise appears to be coming from right behind the center of the dash. Most of the previous noise posts indicate excess noise coming from the dash areas and usually the trucks have a lot of miles on them and were purchased used. This condition just happened over a period of a few days.

 

[BeefDoc]

Does the truck seem to be running OK? No excess pings or hesitation? I have gotten a bad tank of fuel a time or two that has made the engine noise in the cab increase substantially. If I run very much #1 fuel in the winter, my cab noise really gets bad. Just a random thought.

 

[MFrenchek]

BeefDoc. The truck runs great! I had that happen to me a while back, too. Several tanks of fuel have been run through it from different companies. Keep in mind that I also hear a lot more turbo noise, too. Thanks for the thought, it makes sense, but not in this case though. Is there supposed to be a pad above the transmission and bellhousing?

 

[RAM1964]

Did you ever find cause for this as I have same sounds same details as described. I have an 11 3500 6.7 deleted, it just started all of a sudden jet wash noise coming from and it also acts as if it's coming through and supercharging my A/C vents on spool up and exhaust brake activation. Thanks for any thoughts

 

[fest3er]

The first thing I can think of that is in that vicinity and could fail over time are the seals where the A/C and heater line pass through. If those seals have given up or the retaining clips have let go, those openings, and possibly the A/C drain line, are the only ones big enough to allow that much noise through.

Was it 1st Gens that had a problem with trans tunnel joints (or sheet metal) cracking? This is another possibility.