All,

Well I went ahead and did it. Just bought an 06 Ram 1500 5.7L (w/ MDS) QC Big Horn Edition two weeks ago after putting 190,000 miles on my 96 Jeep Grand Cherokee. After breaking in the motor (~500 miles) I decided to upgrade the exhaust to a Flowmaster cat back dual exhaust system and K&N Type 77 Cold Air Intake system yesterday. On my ride home from I started to notice a strange "toosh" sound from the passenger side of the truck every so often from the engine. It almost sounds like a chamber is not igniting the gas and is releasing pressure that is now amplified with the louder exhaust system.

Is this the Hemi ping that most of the forums mention and I didn't notice before? Is there any way to correct this?

My next upgrade to to purchase a Superchips unit and I'm wondering if this will resolve the issue. Thanks.

 

Its the MDS kicking in.

 

welcome to DF...

how about some pics of your truck?

(also moved to 3rd gen forum).

 

As prerunner said, it's most likely the MDS. Aftermarket intake tubes tend to amplify the sound of it kicking in, kind of like a megaphone. It could also be the sound of the EGR. Some people on here have mentioned hearing a sound similar to a clunk that has been related to the EGR valve. There is an aftermarket baffle with a smaller opening to stop the EGR noise. The fact that it is coming from the passenger side tells me that the sound is being amplified by your intake tube. The hemi tick is a light tick tick tick, that you should be able to hear at idle, and it happens either all the time, or in some cases when your engine is warming up, or never happens at all for some people.

 

and to address the superchips question, I don't think that would have any effect on the sound you are hearing. It will just allow you to have more fun with your truck.

 

After posting this to another forum for advice the sound is most likely a resonance from the EGR into the metal CAI tube used by the K&N 77 series. I've seen several references to a EGR baffle but can't seem to find one online or pictures of the modification.

Also I'm not really satisfied with the flowmaster exhaust whenever the MDS kicks in either. I may end up swapping it out for a much more quieter model if I can't find a way to dampen the noise from the exhaust. I may look into the Aero Turbine 3030 as mentioned by someone on DTW as I'm really looking for performance and not sound. I played around with the Tow Mode yesterday and noticed that the MDS doesn't kick in nor does the sound from the EGR when engaged. I guess I'm going to have to play with this until I get it right. Heck I may have a series 77 CAI for sale if it really gets on my nerve this weekend while towing the boat.

Anyone else run into this same experience with a 5.7L w/ MDS? What did you decide to use for the CAI and Exhaust? Thanks.

 

Did a google search and found an EGR Baffle from 3rdstrike dot biz. Looks like exactly what I'm looking for. Thanks for the help. I'll reply once I get the EGR Baffle for those also looking for a solution.