06 ram makes deep sound or bogging sound

[MossyOakRam]

Hey guys i have a 2006 ram 5.7 hemi and i have noticed that the truck makes a deep boggin kinda sound coming from the exhaust when im driving at a constant rpm kinda sounds like a diesel downshifting but not as loud. It happens at any speed except when the truck is in first gear. It makes a bit of a **** or light backfire like sound when the deep noise will kick in but as soon as i accelerate the sound goes away and u just hear the normal exhaust sound. Truck idles and accelerates fine no lose of power. This only happens when the truck is warmed up and i just to say give the truck enough gas to keep it rollin. Anyone have any idea what this can be? When the sound kicks in it changes the rpm by a couple hundred. Ive just started noticing this sound after the truck was straight piped for a day then a flowmaster exhaust was installed. Probably couldnt hear the sound with a stock exhaust. But now the truck sounds like crap lol

 

[MyOhFive]

Sounds like you're hearing the MDS kick in. You're def not the first person to say their MDS truck sounds like crap with exhaust on it.

 

[MossyOakRam]

If im not mistaking mds is the system that drops to i think 4 cylinders? If thats what it is doesnt it kick in at higher speeds? I hear it mostly at 50 kmh

 

[MyOhFive]

Not 100% sure when MDS kicks in, but given that you just changed your exhaust to something considerably louder, I don't think you have a problem per se, thats just how it sounds now when MDS kicks on and/or it could be just the sound it makes when the TC locks up and it drops to cruising RPM.

When I did my cam/headers/3" exhaust theres a throttle position I can hit now, part accel on highway but without a downshift that gives me the lowest loudest rumble I've ever heard it make. I love it. My point is mods make it behave and sound differently. If you don't notice any other symptoms and it runs fine otherwise, I think you're ok.

 

[RonJon '06]

You can try putting it in tow/haul mode. That will prevent MDS from kicking in.

 

[MossyOakRam]

Ill have to try that and see if its even the mds. When its in tow haul mode the mds wont kick on at all?

 

[RonJon '06]

Putting it in tow/haul mode will override it completely. I guess a lot of guys with aftermarket exhaust drive around like that all the time because of the sound as mentioned.

 

[MossyOakRam]

Ok cool ill give er a shot and maybe thats it. Itll be nice to narrow down what is causing this sound

 

[MossyOakRam]

I took truck for a ride and when that deep sound woukd kick in i hit the tow haul button and the sound went away. So i imagine it is the mds. Is that somthing that should be looked at or of concern? What if i drive with the tow haul on all the time would it damage anything?

 

[MyOhFive]

No it's not a concern, a lot of guys report their truck sounding like crap when MDS kicks on after they put some kind of loud exhaust on it.

Driving around in tow-haul will only damage your wallet. It changes the shift points among over things so you may burn more fuel, otherwise no, you're fine.

 

[Harley Harrold]

The MDS allows the engine to go from 8 cylinders to 4 cylinders, when the truck is cruising without a load, and it will go back to 8 cylinders when the PCM detects a load, like going up a slight grade, or accelerating. The MDS is what allows your truck to get it's best fuel mileage. My 07' has a very deep rumble when the MDS is active, and a more mellow sound when it deactivates.

You can get a good programmer/tuner, this will allow you to deactivate the MDS, which will allow the truck to fully operate, in all gears normally. Turning off the MDS will reduce your fuel economy. You have to make a choice as all mods involve a trade off.

 

[MossyOakRam]

Ok thanks alot for the info! Saved me a trip to the dealership and prob a price just to figure out why its doing that

 

[MossyOakRam]

Can mds be disabled on these trucks?

 

[Harley Harrold]

Can mds be disabled on these trucks?

Yes, with a programmer it can be disabled.

 

[MossyOakRam]

Ok has anyone ever done this? Like whats the rpm difference on the hwy