Starting the new truck hunt
We currently pull a Flagstaff 26RLWS, 30' and 7500lbs or so, with a 2002 Chevy 1500HD. Ole Red is getting a little long in the tooth and it's time to consider a new tow vehicle. Looking at Ford, Chevy...
Forum Discussion
BurbMan wrote:
I don't know if the MDS technology is the same in the 6.4 as it is in the 5.7, but I can tell you we bought one of the first 2005 Magnums to come off the line in Sept 2004. First year for the Magnum, first year for the all-new 5.7 Hemi with MDS.
The MDS works in the 5.7 by redirecting oil pressure to deactivate lifters and keep valves closed while the PCM turns off fuel and spark to those cylinders. Sounded terribly complicated, so I got the 7/70 Dodge extended warranty because I had my doubts about the MDS technology. Here we are 13 years later, 142k miles, and the motor has never been opened, not even valve cover gaskets.
I suspect that a lot of problems with AFM/MDS are a result of engine sludge. This technology incorporates several new points of potential failure. The lifters are different than conventional lifters and are a know point of failure in many of these vehicles. Both the GM and Ram engines require that the heads be removed to replace the lifters. I have attached a link that details the GM AFM system, but the Ram is similar....
https://mechanics.stackexchange.com/questions/38005/how-does-cylinder-deactivation-work
