First time for me on Forum. Have 2015 6.7 that has loud knock. I have taken it by 8 places to get suggested new long block, short block, injector, rod, lifter, piston slap to nothing really. Non of them really did more than listen. This happened two months ago. No smoke, no rough idle or metal in oil that can see. I am at a loss what yo do at this point. Any suggestions? I have enough mechanical ability to get myself in trouble but can do some. Just trying to get it fixed honest and not just throw 15-20k like most suggest. Any help is appreciated.

 

You could try posting a video of it so the more experienced guys might be able to tell you what might be wrong.

 

Is it only at idle? There is a TSB for fuel knock at idle on these engines. If you just changed the oil recently and are getting an infrequent ticking sound that is known as the "typewriter tick"

 

If eight different shops have told you that you need a new engine, how do come out and say that you're wanting an honest answer? Any mechanic with a modicum of experience knows what rod knock sounds like, so if they all said the engine is toast, then you have the honest answer you're looking for.

-- Dave

 

If you'd have read his post, you would have understood that the shops have given him all different answers. I suggested he put up a video of the truck running so it can be heard.

 

Mike 1 is correct. I have gotten multiple answers, but nothing other than listening. Sure, maybe the experienced can listen and know exactly, but I thought there would be a better way to determine engine failure, rather than pulling the motor out and spending 15K+ just because.
I will try and post a video later today.

if a lifter failure, does motor need to come out completely? if this group had motor failure, what steps would you take for repairs? Long Block, Short Block, fuel system or lessor options, etc. Not sure where or what is needed for this type repair.

Again, without any smoke, running rough, apparent metal in the oil and running it for the past 2 months now, I would have thought catastrophic motor failure would have been just that.

 

No sir, it mirrors with RPM faster and slower depending

 

Well I hate to say it, but if you have metal particles in your oil then they've been going through your crank bearings and anywhere else oil is supplied, so I would have to agree that you probably need a total rebuild if this is the case, but you know internet diagnostics...aren't reliable.

 

sorry my wording was incorrect, meant to say NO apparent metal

 

If it is a lifter that is bad which is very unlikely as you don't get that heavy knock with a lifter but if it is a lifter that is bad then you have to pull the heads to get them out. If it has spun and ruined the cam then you have to pull the timing cover as well to slide the cam out the front. It is alot of work but it can be done in the truck. Bottom end damage cannot be done in the truck and will necessitate a new short block or a complete rebuild.
Get yourself an oil analysis kit and have see whether there is metal in the oil or not, that will tell you for sure. If there is no excessive metal than it is highly unlikely that you need to do any actual engine work.
Don't be upset at the shops either. you brought it by for an estimate, without tearing it apart and seeing what is exactly wrong with it all they can do is guess at what they think is the issue and recommend the worst case option so they don't lose their shirts.

 

I appreciate the comments as I have learned a lot. My frustration is and was, nobody wanted to go thru the process of discovery, rather just throw a motor at it and move on. I have come to the terms it may be a new motor, but breaking down what and why first is a step I must take. The only way to determine is taking motor apart step by step. Everyone is scratching their heads because it runs fine it just has loud tick. I will try and make video today and post it. If I had shop room I would start into it myself.

video to follow

 

Have you tried using a stethoscope to isolate or pinpoint where the ticking is coming from? It could be something as simple as a loud injector or even an exhaust manifold leak....waiting for the video. It may help

 

Video for everyone’s enjoyment

 

That didn't sound good at all...... It really sounds like metal hitting metal, like a rod against the pan, or maybe hitting the oil pickup tube. If you have room under there, I would drop the pan and inspect before buying an engine.

Even if you pull the engine, inspect first. I could be something minor.

 

There's a slight possibility it could be a fuel knock. I've had a Duramax with a few bad injectors sound similar. I've also had a Cummins that sounded just like that & needed a new motor. Unfortunately, throwing injectors at a 6.7 is MUCH more costly than a LB7 or 5.9 Cummins. I dropped $2500 on new injectors for the Dodge to not fix the problem.