2015 Engine Knocking/Pinging under load

[14KGVWR]

All,

First - great forum and I am glad to have joined as a member. Hoping some of the experts here can shed a little light on my issue.

So I have a new to me 2015 3500 RAM Dually with 28K miles on the clock. This is my first truck but NOT my first diesel. I've searched these and other forums and don't have a good answer to my perceived but what I think is a real issue. It has been dealer maintained in Virginia for the first 2 years of it's life and is current with all maintenance.

In short, under light to moderate acceleration (unloaded) I get a very perceptible and audible engine knock/pinging sound. I can recreate it at will and it will get louder the harder I push it in lower RPM ranges. It goes away at higher RPMs. Very much like a high compression gasser running on low octane gas. No CEL. No other indications of anything wrong. This is NOT diesel clatter which I am familiar with.

At first I thought this was normal but over Thanksgiving I took my Father-in-Law's 2014 RAM dually for a spin and his did not make any such noises. I took a new truck out for a test drive and it did not make these noises. I am concerned that this is an injection timing issue and I may be doing damage to the pistons/rods under these circumstances. I've been driving it modestly and without much load but plan to do long cross country trips towing a heavy trailer soon.

I will be taking it in to have it checked out but I'm afraid without a CEL the dealer won't touch it. I'm a "drive it like you stole it" kind of guy when everything is running as it should and should be enjoying this new truck...but something here isn't right. Any insights and input are greatly appreciated.

 

[Tuesdak]

By the sounds of it I agree with your thoughts of too much timing for the conditions. We owned a 2008 Duramax (insert rant about GM's worthless cooling systems that can't cash the power check the engines write here.) that would stay in double overdrive (aka wrong gear for the load) and allow ECT's and other temps to skyrocket while towing minor grades. Just not enough RPM and no mechanism in GM's tune to reduce timing when temperatures got hotter. IAT ECT CAC temps all mean the injected diesel evaporates faster from hotter air and lights off faster resulting in the "static" timing being too much for the really hot temperatures. The gasser ping noise would result as the now excessive timing attempted to drive the engine backwards. Downshifting before the said grades would reduce this noise some as well as reduce the overall ECT rise. (Was same route towing 5 days a week so you get to know the road.) B99 would also reduce the ping noise some over #2 diesel.

Myself as what you describe could be a temperature/timing thing I would verify all the temperature sensors are reading within spec, cooling system is full, t-stat is ok... There are many things that knock and ping on diesels. Frankly good luck tracking it down as it can be a long journey.

Injector knock, leaking injector(s) come to mind as well. Any smoke or reduced MPG?

 

[14KGVWR]

JDoremire,

Thanks for the response and feedback. I am afraid I might be in for along road ahead. Outside temps don't seem to make much difference. It's been doing this since I bought it in April of 2017 - drove it from VA to CT. Did it the whole way home. Now I'm driving it in single/teen F temps and it still does it (when cold and when fully warmed up). It's damn cold up here in central CT right now. I've been monitoring temps and all are good and lower than I would have expected given my other diesels. I'll check coolant levels tonight and report back. Doubt the Tstat is stuck closed - that would have caused other issues long ago! No smoke at startup (white) or black under full power. Fuel economy right around 18-20 mpg on the highway

This is definitely not something loose! I'm guessing too much pre TDC fuel injection causing too early ignition. That much I know is bad for piston tops and internal components. Timing comes to mind.... Leaking injector could definitely do this too....hopefully just a minor adjustment needed.

I'll have them look at it this week when it goes in for the next two recalls! I've had the truck 9 months and so far 4 recalls!

 

[Tuesdak]

Recalls are a good thing. Means FCA is fixing it rather than ignoring it like our OEM's love to get away with.

 

[Cummins12V98]

Welcome aboard! I have the same truck, are your Firestone bags aftermarket of do you have the Factory air ride? Thanks for filling in your public profile!!!

" Fuel economy right around 18-20 mpg on the highway" I have to say you have a GOLDEN truck getting that mileage. I'm thinking you are glancing at the lie O meter at 55-60 with those numbers.

My truck sounds just like yours (i'm guessing) it does some rattle when going thru the gears. I actually like it and I doubt there is anything wrong.

 

[sag2]

There isn't anything you or the dealer can do to change the timing so you will not get anywhere with the dealer. I doubt there is anything at all wrong with your truck. They each seem to have their own personality. If it is running good, getting good mileage, and no CEl just drive it. I used to hate meeting with customers with the new trucks because they are so quiet they can hear noises that you could never hear before. Believe me that if there is something wrong it will make real noises. Stock trucks don't hurt internal parts, and if it's an injector or two that is causing it most likely caused by contamination so it would not be covered by warranty ayway. If you want to try something to rule out a dirty injector pick up a bottle of CRC Diesel Fuel Therapy, available at most large Napa stores. It's the same cleaner as the Mopar branded cleaner. But I still doubt it will make much difference.
I would not worry about it. Besides it has a bunch of warranty left, and still can't recall the last truck I saw that hurt anything internal.

 

[Newsa]

Yeah. My truck just sounds like it's happily digging in when under a load. Definitely can hear it when loaded. Not any concerns about these "normal" noises.

My wife complains about it, but, I tell her it's not a Chevy.

 

[14KGVWR]

My Firestone airbags were installed by the previous owner. these are aftermarket and manual as in you pump them up with compressed air via a fill port on the rear bumper. Good for leveling the truck when loaded. I wish it had factory air ride but no dice.

Yep - that's what the gauge on the dash says when cruising on the highway at 65 (actually 21mpg on flat ground) I've only run 3 tanks of fuel through it so I haven't had a chance yet to get an accurate reading over time. Not much highway as I use it as my Home Depot Hauler now and Pellets for the Stove.

 

[14KGVWR]

sag2 - ordered some CRC Diesel Fuel Therapy - will see if it helps. Hope it's not a bad/dirty injector(s). Truck is and will remain stock. Interesting they can't adjust timing....all my other diesels you could via Cam sprocket position or electronically advance/retard. Are these trucks that old school!? ;-) Again it's just weird that mine does it by my FIL's truck, only 1 year older, sounded great with no noticeable sounds like mine - and his is a tradesman with less sound deadening insulation. If it wasn't for that and comparison to new I'd just accept it as is.

The previous owner maintained this thing meticulously so I can't imagine with only 28K miles there are problems with injectors but mechanical systems can and do fail. It's a CPO so powertrain warranty is 7Yrs/100K miles which makes me feel better but I want to rule out anything I can prevent. Thanks for the input guys - much appreciated.

 

[Tuesdak]

If it's just timing ping.. we put on 115K miles on the Duramax with the ping and no real problems from it. (Other than running so hot before the obsolete thermal spring fan clutch would get the 25" fan with the program. The fan delay also allowed hotter air coming out of the CAC and made the ping situation worse.) Context the extreme heat of AZ...

You may try some cetane improver and see if it makes the ping worse. Yes, worse as more cetane means the diesel lights faster and thus you are looking at timing. A video with good sound can't hurt. But with the "normal" posts above do you really want to bother?

 

[mhstevens]

I have the same rig, and it seems like its doing the same thing. I had a 99 and and 04 Dodge diesel and they didn't sound this way. When I got the 15, that was one of the first things I noticed and was concerned about it for awhile. I figured with the 100K warrantee, if there was a problem it would get fixed. I have a little over 80k on it now and it still does it a bit and I guess I'm just used to it. I full time with a heavy 5th wheel and haven't had any issues with it at all (other than the various recalls). I did start using the recommended fuel additive intermittently and I don't see that it has affected the noise at all.

 

[kthaxton]

My gut instinct is the same as the others.....probably normal.
Do you know your gear ratio and your father-in-law's? I'm curious if his is geared lower than yours and this is why yours "pings" when his does not? (his would continually be under less load if geared lower)

 

[Cummins12V98]

My Firestone airbags were installed by the previous owner. these are aftermarket and manual as in you pump them up with compressed air via a fill port on the rear bumper. Good for leveling the truck when loaded. I wish it had factory air ride but no dice.

Yep - that's what the gauge on the dash says when cruising on the highway at 65 (actually 21mpg on flat ground) I've only run 3 tanks of fuel through it so I haven't had a chance yet to get an accurate reading over time. Not much highway as I use it as my Home Depot Hauler now and Pellets for the Stove.

You may want to fill tank to the top several times and hand calculate then report back. You are getting no where near that mileage!

 

[Killer223]

why do you all say he's not getting that MPG? mine will get 19's rather regularly. granted it's an 08. but i can see it for a stock truck....

 

[MarkEagleUSA]

View attachment 101139

What app is that?

 

[Killer223]

It was gascubby, but it was purchased by feully mobile. If you go to their site they have links for Apple and Android. It has mpg and all maintance tracking. Love it. I have the paid version.

 

[Jnemjo]

I actually have a 3rd generation 2006 3500 dually but I just happen to come across your post and wanted to add on that you are not alone. I bought mine four years ago with only 28,000 miles. I noticed the pinging within the first week. I bought the warranty so I had dealer check it out. They said all was good but they knew what I was talking about and said some trucks do it. Most don't but the ones that do will last forever just like the ones that don't ping. It's at 90k now and sure enough never been a problem. I haul a 12,500lb horse trailer 8 times a year and she pulls like a freight train. I love this truck and though it took awhile I did get used to the pinging.

 

[Missouri Mule]

It seems to be similar to a octane knock/ ping on gasses.
My 82 Buick pinged a lot when I first bought it. I switched from 82 or what ever the lowest was ( recommended = factory) to the highest 92/93 and the ping went away. Plus I got 20 around town and 30 to 32 on the highway ( 1rst year Buick had a lock up tq.
I try finding diesel with a higher centane number.
I filli up at BP both Mule and Moose seem to run a lot better then with Citgo or race track fuel. Loves charges more for credit cards, but their fuel was not that great either.

 

[Cummins12V98]

why do you all say he's not getting that MPG? mine will get 19's rather regularly. granted it's an 08. but i can see it for a stock truck.... View attachment 101139

Is your truck an automatic with 4.10's? Also does your truck weigh nearly 10k with passengers, tool box and hitch?

 

[Newsa]

Correct me if I'm wrong. But ping in a gas engine means the gas is igniting too readily based on temp and compression of the combustion chamber. Higher octane is supposed to keep it from igniting too early, and instead igniting when the spark plug lights. I think the noise sounds like it's coming from the valves.

Ping in a diesel is igniting closer to top dead center than it's supposed to? And the noise is still coming from the valves. Cetane improvers work differently than octane improvers. Cetane makes the diesel ignites more readily.