Having issues

[Preston S]

So i have a 2015 Power wagon with the 6.4 in it with 147k miles on it. I just replaced spark plugs and the injectors due to having a misfire in cylinder 8 and leaking injector. Now it can't go over 4k rpms it kills itself when i turn the wheels all the way left or right and won't turn back on for a few minute of sitting, it shakes while accelerating at low rpms. Anyone have any insight as the what would be going on? My mechanic thinks it might be the ecm, none of the dealerships in my area are trustworthy so I'm trying to figure this out without them. Any advice is appreciated

 

[Fast69Mopar]

So i have a 2015 Power wagon with the 6.4 in it with 147k miles on it. I just replaced spark plugs and the injectors due to having a misfire in cylinder 8 and leaking injector. Now it can't go over 4k rpms it kills itself when i turn the wheels all the way left or right and won't turn back on for a few minute of sitting, it shakes while accelerating at low rpms. Anyone have any insight as the what would be going on? My mechanic thinks it might be the ecm, none of the dealerships in my area are trustworthy so I'm trying to figure this out without them. Any advice is appreciated

You are going to need a good scan tool to diagnose anything. You need to see what the cam and crank sensors look like, the cam/crank difference, fuel adaptive memory etc. Without a scan tool you will just be guessing and throwing parts at it. If your mechanic has a scan tool, which he should have, ought to be able to diagnose it.

What spark plugs did you put in the motor?

Did you replace all 8 fuel injectors? New OEM Mopar? Aftermarket?

 

[Preston S]

I'm not sure what scan tool it is he has but i have a mac tools one that reads everything, but when he went to clear the misfire code he was saying it was on the ecu permanently but when i got in it this morning there was no lights on the dash.
I put ngk ruthenium spark plugs and replaced all 8 injectors with aftermarket ones
While he was doing the work i had him look at the rockers and the cam he said they all looked clean with no pitting or flat spots.

 

[Burla]

You have to post up the codes here bud, run codes ob2 and post the numbers. CEL or not, tell us what codes are showing.

 

[Dodge 1500 4X4]

Codes, And did he check the rocker arm movement, especially on Cylinder#8, press Accelerator pedal to the floor and crank the engine to check movement of rockers.

 

[Preston S]

So a code showed up on the scanner finally and its p1416 cylinder 6 reactivation control performance.

 

[Burla]

That is good news if that is all that is really going on. gas, air and spark, it sounds like you either have an issue with air or a sensor has failed. You can start by doing all of the cheap stuff that probably needs replacing at this point anyhow. Air filter, pcv, o2 sensor, maybe that will fix it maybe not, but if it is a larger ticket item those will only serve you well to have replaced. Does any 6.4 have mds, does yours? what is your oil psi at idle and at 3000 rpms? change oil lately?

 

[Burla]

last time you cleaned throttle body?

 

[GTyankee]

P1416 is getting set because MDS failed to disengage for cylinder 6. Problem could be the wiring harness/connector to MDS solenoid #6, the solenoid itself, or the cylinder #6 MDS lifters. The MDS solenoids are under the air intake manifold.

possible causes are listed, the first cause is most likely, the last one is the least likely

P1416 DODGE Possible Causes What does this mean?
Low oil pressure or blocked oil passage
Faulty MDS Solenoid
MDS Solenoid harness is open or shorted
MDS Solenoid circuit poor electrical connection
Faulty Engine Control Module (ECM)

P1416 DODGE Description When all criteria has been met, power is supplied to each MDS Solenoid when the engine is making a transition from 8 cylinder mode to 4 cylinder mode. By actuating the solenoid, oil pressure is raised to the pair of lifters that coincide with each particular solenoid. The oil pressure pushes in the locking pins that allows the lifter to collapse, decoupling the valves and camshaft.

Read more: https://www.autocodes.com/p1416_dodge.html

Makes me wonder if you could switch the MDS Solenoid with another MDS Solenoid on the engine, if the code switches to a different position, then you have a bad MDS Solenoid

 

[Burla]

Yes, but when it goes into mds the ecm has to double the air to the 4 active cylinders, and fuel by the way but I'm guessing air first. I can see why the mechanic thinks ecm, but at 149k miles I want to know what shape the air intake system is in. If it hasnt been touched, number one it needs it anyhow, but it may be the bottom line condition here preventing the ecm from taking in enough air. I start low and move to bigger ticket items if needed, depending on what condition the engine is in. More info posted in the first place is better for us, how has the maintenance been?

 

[Burla]

Use shifter or tow haul to lock out mds for like a week, see if this still happens.

 

[Preston S]

I change oil regularly when the dash says 10% haven't cleaned the throttle body, air filter is a k&n i clean every 2nd oil change. I have noticed that the oil pressure has been sitting on the lower side of normal here recently but i just figured it was due to being about time i needed to change the oil.

 

[Burla]

Never in 149k miles was Throttle body cleaned? So this would be first before you do anything, super easy just don't drop them long bolts or the throttle body, and get some throttle body cleaner. May not be the issue, but if the issue is something else, you will want proper air/fuel mix and for the cost of a cleaner it is well worth your tine. Service air filter as well. I'm guessing pcv also not done which feeds throttle body, over due at this point, but I'm not sure what the 6.4 has for a pcv or how guys clean it, if memory serves me you don't have pcv? Have to research that.

 

[RedSRT4Me]

While he was doing the work i had him look at the rockers and the cam he said they all looked clean with no pitting or flat spots.

Just curious. How does one check the cam for pitting or flat spots without removing any of the components such has harmonic balancer, timing chain cover etc? Hell, how is he checking those lifters in your block unless the manifolds and heads are pulled??

 

[Burla]

Anyhow, the code thrown isnt what we usually see with lifters so I hold out hope it isnt internal.

 

[Preston S]

I shouldn't say he checked the cam itself he did pull the valve covers and checked the rollers on the rockers which usually if the rollers are good there isn't anything on the cam. I should also preface i know nothing about these little motors as i work mostly on Cat motors so I'm assuming things are atleast somewhat similar in functionality.

Also after going over what has been said here he did tell me he cleaned the throttle body.

 

[Burla]

OP you said misfire in first post, and these are known for misfires leading to cam lob failure, but those codes are different then the one you posted. Let's go back, did you ever get the misfire code? or your mechanic get that code? He sounds good if he in fact cleaned the TB, it wouldn't hurt to verify that, just go look at it, nothing personal just verify. For us to be real helpful, we need all of the info possible and all that was done. Was this a professional mechanic on invoice or more of a friend type mechanic? If pro what was done, as in everything? He pulled covers but made no effort to fix this? not even mds solonoid or o2 sensors or anything?

 

[Burla]

Anyhow, I can see why he said ECM, I think you can get those programed by vin w/o using dealer, but I'm not sure about that. It might be a dealer thing. If you get a mis fire code then you might be throwing good money after bad.

 

[Preston S]

The misfire code is what started the whole repair ordeal. After replacing the injectors and spark plugs the misfire was cleared he drove it a couple of days to make sure everything was good and was going to do a state inspection for it but when he went to do the misfire code came up and wouldn't clear off the computer. He told me to take it to a dealer to see if they could flash it since his scanner wouldn't clear it but other than that he said it ran a drove perfect. I went to pick it up had no lights on the dash showing anything wrong but it wasnt running right. As far as my mechanic he is a professional but he did it at his home shop since we've been friends since high school.
But these issues happened after he had it so I'm trying to figure out what's wrong so i can either fix it myself or just tell him what to replace

 

[RedSRT4Me]

I shouldn't say he checked the cam itself he did pull the valve covers and checked the rollers on the rockers which usually if the rollers are good there isn't anything on the cam. I should also preface i know nothing about these little motors as i work mostly on Cat motors so I'm assuming things are atleast somewhat similar in functionality.

Also after going over what has been said here he did tell me he cleaned the throttle body.

Problem is this isn't a DOHC engine. This is an old school so to speak pushrod motor. The rockers in the head are connecting to valvesprings on one side and push rods on the other. The push rods are then connecting to your lifters in the block. Not the head. Unless the engine is disassembled there is zero way of determining that your cam/lifters are free of flat spotting that you mentioned.

Why is this important? Because it's not accurate info to diagnose this engine with what has been given so far. We can keep guessing though

Edit: fair enough I missed the CAT engine part. With that said run a compression test on the cyls and go from there. Should be a pretty quick indicator if you have a leaky cyl