Coil Pack or Lifter Failure??

[ScubaSteve42]

2012 Ram 1500, 66k, 5.7, vararam/magnaflow catback/tuned.

Hey, all. I appreciate all the info on these forums, and have been having trouble finding more info about some issues with the Ram.

Normal daily driving doesn't come with any issues, but when I "get on it" with some above-average acceleration, I'm getting some kind of failure/misfire. At first I thought it was a transmission issue, since it sounded like the truck was downshifting before taking off. The truck would start accelerating normally, then let out a "WAAAAAAAAAATTT" without accelerating, then after a few seconds something would kick in, and the and the truck will take off. Took it to the dealer (right before warranty expired) and he said tranny was fine, but I needed to change my plugs. Plugs are changed, but the problem persists. While I was at the dealer, I had the exhaust manifold repaired, and haven't had any ticking.

To me, this means coil packs are bad, but I don't want to rule out lifter failure. I'd rather not replace good coil packs, and still have the issue.

about 70% of the time use the "shift to 6th" trick to knock out the MDS. Although, I've experienced the issue whether MDS is active or not.

 

[ScubaSteve42]

worth mentioning, I haven't had any codes come up

 

[SYKRAMMAN]

Then don’t “ get on it “ and drive normal. Jk. Pop off the valve covers and take a look, switch some coils around to see if anything changes.

 

[VB712]

I’m pretty sure if it was a lifter issue you would have a very noisy engine.

 

[huntergreen]

Subed.

 

[jotin]

I’m pretty sure if it was a lifter issue you would have a very noisy engine.

Not correct. Half the time it a lifter issue. There is ZERO noise.


Sent from my iPhone using Tapatalk

 

[Mr Papagiorgio]

Lifters are often very quite when they fail and even can trip a misfire only intermittently.

 

[ScubaSteve42]

I've been toying with it a bit more, which has been nerve wracking, but it seems the "stutter" only occurs right at the 3000 RPM mark. It's been suggested that this is an MDS system failure, caused by a bug in my tune. I don't know who tuned it, so I guess it's possible. I'm not ruling out the lifter, but the consistency of the WOOOTTTTTTT, makes me think that it is software.