Hello Ram Gurus.

I'm hoping someone could shed some light on an issue that I've just noticed. (Not sure how long it's been there, but I think it's new)

When I'm going up a steep incline in my ram, it will occasionally jump up rmps and drop and jump up and drop back to normal. It will only do this if I'm cruising up the hill at a constant speed. If I give it a little gas to change the gear it's fine.

When the RPMs jump I'm hearing a very quiet sound (that I believe is coming from the back end) which my g/f says it sounds like a rattle but honestly, the first thing I can think of when I hear the sound is the rattling/knocking noise of of diesel engine, just much much quieter.

My thoughts are some type of sensor could be gone and the truck is unsure if it should be changing gears or not. i honestly don’t know.

Before I brought it to any Stealership I would love your input.

Thanks all.

 

What year truck? Try pushing the Tow/Haul button to turn it off and see if that helps

 

My bad, it's an 07 4.7l SLT Reg Cab. (With a Superchip tune)

I don't think this issue is due to the tune as I didn't make any adjustments to the gear changing. I only loaded the standard 87 tune.

weedahoe, thanks, I'll give that I try this evening on my way home from work.

If is does fix it, what are your thoughts?

 

Ok, so I drove up and down a bunch of hills this evening and it seems to me that it only does it in normal drive. Anytime I put it in "tow" it wouldn't make the sound.

 

Any idea?

 

Sounds like the MDS is kicking on and off. As the engine gets to a point where it is cruising and not a lot of engine load, MDS kicks on and deactivates 4 of the 8 cylinders. But when it does and going uphill the PCM detects it needs those other four to keep making it uphill so it kicks MDS off and this keeps happening back and forth over and over. So it is normal per se` but a PITA. Lots of guys complain about MDS and how it works

 

That's stupid, but sounds like nothing I should have to worry about? (Which is good news)

Is this something that I should be able to adjust with my Tuner? Maybe adjustment of gear changes?

 

He's got a 4.7L, no mds?

 

Uh oh, youre right! I missed that 4.7 part. No MDS on a 4.7 so that cant be it. Back to square one.

 

I need to test this theory out more, but it seems to only do it when the RPMs drop really low going up hill.