I have a 2007 dodge ram 1500 5.7L Hemi, Big Horn with MDS -
I purchasedthe truck in August and have had 5 oil changes since I bought the truck - 18000 miles on it. The dealer told me mopar oil was extra and used motorcraft 10w-30 blend. I asked on the forum and received input that this oil was fine. (I don't think I told them I had MDS). Now after reading the manual and checking the forum - I should probably beusing Mobile 5w-20 and am a little peeved that the dealer didn't use or even push this since I have MDS - I would have gladly paid more.

Bottom line - I will use mobile one 5000 5w-20 from now on.

Has there been any damage so far?
Should I use a cleaner?
any input?

(for the responses that say I should do it myself - I know, and your right)
(sorry for another oil question)

LOVE THE HEMI!!!!!!!!!!!!!!!!!!!

 

Do it yourself.......................................... .................................................. .......
Use Amsoil...
ive hear mds owners say their truck ran funny with it in there. not sure if any damage is done, wonder if theyll void a warranty claim due to that even though they were the ones doing the oil change

 

Just switch to some 5w-20 and you should be fine, change the fresh 5w-20 after 500-1000 miles to flush all the old stuff. May not be completely neccessary but it's better safe than sorry.

As for the mobile, that's good oil, but i also think Amsoil is the best oil for our hemi's.

 

I suspect your Hemi is fine. I'm guessing that the lower viscosity is needed to ensure that the deactivation device has the reaction time needed to guarantee a seamless transition between 4cyl and 8cyl operation at lower engine temperatures, but that's just a guess.

I recall from posts a few months ago that some folks with MDS have run 10w30 for one reason or another, and they found that MDS kicks in anyway. Not sure if I saw it in this forum or another.

Check out write up and pictures at allpar.com:

http://www.allpar.com/mopar/new-mopar-hemi.html

One of the pictures shows the path that the oil takes to deactivate the valves of one of the cylinders and the device itself.

I do my own oil changes. Cheap-*** that I am, I use whatever Wal-Mart has in stock -usually Valvoline or Castrol. Works just fine. Will have a local shop do it next time since they're running a special - $12.95 for oil change + tire rotation. I'm bringing my own oil and will be there to watch them pour it in.

 

With the MDS you should use 5w-20 for it to work properly.

I highly recommend AMSOIL.

Speed Safely,
AL

 

Should be fine. "They" should've known an '07 has MDS and therefore needs 5w-20. A dose of Seafoam just before you drain the oil may help get more of the 10w-30 out (drain it warm). I've read that you put in the Seafoam ten or twenty miles before you drain it. It's also time you ignore that moron dealer. If you plan to, now's the time to switch to synthetic.

 

I don't think it's done any harm, but the 5w-20 is supposedly needed for the MDS to function properly.
Funny how different it is from dealer to dealer, Pappy_FB has an '06 4x2 QCSB Hemi with MDS and his dealer told them it was fine for him to change it himself, but his engine warranty would be void if it was ever found that he had anything other than 5w-20 in there.
And here YOUR DEALER fails to even use it...[&:]

 

Not sure how this helps, but the following is straight out of the service manual..

For 3.7L/4.7L engines SAE 5W-20 engine oil is recommended for all operating temperatures. For 5.7L engines SAE 5W-20 engine oil is recommended for all operating temperatures.These engine oils improve low temperature starting and vehicle fuel economy. Refer to your engine oil filler cap for the recommended engine oil viscosity for your vehicle. Vehicles with 5.7L engines equipped with Multiple Displacement System (MDS) must use SAE 5W-20 oil. Failure to do so may result in improper operation of the Multiple Displacement System (MDS).

OPERATION
The Multiple Displacement System (MDS) provides cylinder deactivation during steady-speed, low-acceleration and shallow grade climbing conditions to increase fuel economy. Both four- and eight-cylinder configurations have even firing intervals, providing smooth operation. Two cylinders on each bank are active when the engine is in four-cylinder mode - every other cylinder in the firing order. All of the cylinders that are deactivated have unique hydraulic valve lifters that collapse when deactivated to prevent the valves from opening. Engine oil pressure is used to activate and deactivate the valves. It is delivered through special oil passages drilled into the cylinder block. Solenoid valves control the flow. When activated, pressurized oil pushes a latching pin on each valve lifter, which then becomes a “lost motion” link. Its base follows the camshaft, but its top remains stationary, held in place against the pushrod by light spring pressure but unable to move because of the much higher force of the valve spring.
NOTE:It is critical to use the recommended oil viscosity in 5.7L engines that use MDS.
Deactivation occurs during the compression stroke of each cylinder, after air and fuel enter the cylinder. Ignition then occurs, but the combustion products remain trapped in the cylinder under high pressure, because the valves no longer open. No air enters or leaves. During subsequent piston strokes, this high-pressure gas is repeatedly compressed and expanded like an air spring, but fuel is not injected.

 

i've a;ways used 5w20 castrol GTX in my 06 5.7 with mds and i think it's smooth, i don' have any experience with any one else's but most of the time i don't notice the MDS kick in or out, sometimes while it's cold i may notice it but i usually let my truck warm up a little before i move. I use the castrol for one reason, when i was in autoshop in high school i did rebuild ona teachers car at 200,00 mi and the thing was in pristine condition on the inside, the teacher said he always used plain castrol every 3,000 mi. since then i've been a castrol guy. just my .02. everyone makes their own choices, i change mine every 3,000 and havent noticed any sludge or shavings in my oil(yes i check my oil) but that's just me

 

I think I use 5w30. not for sure. I always forget.