what is the reason mds will not operate with anything other than 5-20 wt. how does a 5-30 negate the mds? tks all
That's the article...thanks for finding that Dak. I noticed that they say it "may" cause a conflict with the MDS. Now, the interesting question is "how". The MDS works through the valvetrain lifters from everything I've seen and read...Allpar has one or more excellent articles on this. Hydraulic lifters obviously work on oil as the hydraulic medium. On the MDS models, there's another element functioning to disable the alleged unnecessary cylinders at the appropriate time. So the question would be, does going to a heavier oil possibly disable MDS or does it cause it to malfunction to a point where it comes in at a very inappropriate time? I would lean more toward speculating that MDS wouldn't kick in as frequently with heavier oil, perhaps because the oil is too thick to let the lifters disable those cylinders. But hey...I'm an old GM guy who knows very little about these Mopar engines and all their new fangled, space age technology...LOL!
wvcoolvanilla, if your question is for me, i am asking because i was buying some 5-20 oil and was told that since warm weather was coming up i should use a heavier oil. went through the speal about mds and was told that a 5-30 would not affect mds at all. i bought 5-20 anyway.
no i am staying with 5-20 wt oil. i have visited parents in tavares florida for a couple weeks at a time in aug only to find out that it was hotter in jersey than down south, and it was dam hot in florida, we have 100 degree weather here on occasion.Warmer weather in NJ won't be warm enough to need heavier oil. If I don't need it GA you defintiely don't need it in NJ.
I have noticed that happening on mine since the last time we got the oil changed at the dealership. I'm guessing they put the wrong grade oil in it. That was the last time they are changing the oil anyways.I know from personal experience that it causes the MDS to function erratically and "harshly"...so much so that the dealership went out of their way to make up for their mistake when I went back.