Been trying to find an explanation as to what is different internally on the 5.7 Hemi that Dodge puts in their cars (Charger, Challenger, 300C, etc) and what they put in the Ram trucks. I called my dealer and spoke to the service manager and his exact words were "I honestly don't know what is differently internally".

Their is a present recall on some (over 50k miles) auto trans equipped Dodge cars due to the timing chains snapping. It has to do with the MDS system. But i'm curious as to why no Ram's fall into this recall?

http://www.hotrod.com/news/chrysler-...-chain-defect/

 

Mds is controlled by the computer, might just be a programming issue in some of the cars.

 

I guess it's possible. But if the whole issue lies with the computer program, then wouldn't the recall simply a be a re-flash vs a replacement of the timing chain and related components?

Using the 2011 model year as a reference, From what i have read the Ram's 5.7 Hemi put's out approximately 390HP and the Charger puts out 375HP. Seems too small a difference to be anything more then something to do with programming or perhaps a cam. On the same note i cannot figure out why they would have a detuned (and by only 15HP) engine for a sports car vs a truck. Seems an awfully small difference.

Fuel economy numbers for the Ram are 13/19, The Charger 16/25. But i'm pretty sure the main reason for the big difference in MPG is the weight difference and aerodynamics. Curb weight on each (depending on options) is 3,961 lbs to 4,450 lbs for the Charger and 4,718 lbs to 5,538 lbs for the 1500 Ram.

 

The gear/chain replacement may be because they suspect that damage has already been done.

 

The recall on the timing change for the challenger as I have read somewhere had to due with the chain not being as strong as the Ram and the tensioner for the chains were to weak. Not a problem in the Rams. I haven't heard anything about the cause being the MDS system.

Some of the other differences are the cam is designed for more torque in the Ram and the intake has short runners and long runners with a flapper switch to change position keeping the torque high in low rpm and high rpm.

 

Well based on the link i posted and what Chrysler is saying, the recall only affects cars with MDS because while the MDS is not what is defective, the failure occurs when the MDS is in operation. So technically MDS is the "cause" of the failure of the poorly engineered parts. It just seems this is yet another easily avoidable problem that would have never happened had they NOT used plastic parts in a critical component of an engine that if it fails you will have guaranteed catastrophic engine damage. How much money were they really saving by using plastic over steel? A few dollars per engine?

 

Any 5.7L in a car has MDS, the 5.7L in the 2500 does not, that may be why they associated MDS with the Hemi. If it was the MDS system causing problems it would eventually show up in the truck Hemi even with the beefier parts and none have shown any problems and the MDS goes back to 2004.

I would wager on weak parts in a performance engine. I don't see how they could verify it was the MDS unless a computer was hooked up to moniter the engine at time of failure. Just be glad it is not an EcoBoost, They are starting to show their age with stretched chains and worn guides and tensioners.

 

Apparently MDS does not exist in 5.7 Hemi's with the manual transmission. Not sure where the failure data is coming from unless perhaps they did their own testing?

 

Im pretty sure our intake manifold is different as well with the active butterfly that changes runner length based on RPM and Load to get bottom end power as well as top end power.

 

I have had this issue for 2 plus years. I know for a fact the trucks fall under this as well. The amount time and frustration trying toget the dealer and Chrysler to own up to this is unreal . I had to almost drive it down the throats of the techs that it's an mds issue and timing chain issue. Chain was replaced about two weeks ago and is good so far, but to speak of the unprofessional side of both the dealer and Chrysler is unreal. I'm not finished as I see they both know the issue and are covering up the facts. I'm in the protest of getting of getting docs and recordings made to Chrysler for the sake of possible legal procedure. There is many of us out there as posted on many other threads. To be told by your dealer that your truck is drivable and it poses not safety risk then just drive it. Seriously*~~ anyone wants more details please contact me through here and I can give full storey. Good luck to all, and yes. Their is no difference wth issue regardless of truck or car. Chrysler seems to be gambling on no fatalities and having people get frustrated enough to just trade in their vehicle. Something I refuse to do.