Name this engine noise... (video)

sootie

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is it missing at all? pull the oil fill cap off and see if it is a steady stream or a rythmic puff-puff-puff. Pull the air intake and see if the noise is louder towards the turbo inlet.
 

me2

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Is it safe to run ? It knocks pretty hard in real life.

I'd say there is no significant miss fire. This happened at idle. I never revved it up.

Any chance it is a sticking valve and I could just replace the head(s) and have a running engine ?

It was down on power a bit before it did this. Didn't rev out properly. It threw a code a few days before this. I haven't pulled the code yet.
 
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me2

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It has 200K miles on it. It is completely stock.

It was regenning quite a bit before it happened. Fluid levels appear normal.

Broken crankshaft ?

Spun rod bearing ?

Dropped valve ?

Cracked piston ?

Head gasket ?
 

sootie

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not sure what "safe to run" is, its damaged now...and most likely will require a complete teardown to repair.

if the thumping is in the intake when you remove the air cleaner, i would move towards a failed lifter or a valvetrain issue.

if there is a puff puff puff out the oil fill, i would suspect cracked piston.

No, it wont be a sticking valve.

I have never seen a broken crank on a six four.

Dropped valves usually barely run and make a ton of smoke while doing so (typically whats left of the piston is in the pan and the rod and wrist pin are clanking around the cylinder).

Pull the code and see what it is.

Drain the engine oil and see how much/what material comes out. Maybe cut the oil filter apart too.
 

me2

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Then it has to be a cracked piston or a spun rod bearing.

If it is these, can the engine be salvaged ?
 

me2

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Probably a cracked piston. The regens were probably caused by oil blow by when the crack was small. Now the crack is big.

A spun rod bearing probably wouldn't just happen at idle and it doesn't explain the the regens before it happened.

Will the bore be ruined if the piston is cracked ?

Can the engine be pulled without removing the cab ?
 

sootie

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Could be a bad injector as well. If it was me i would be at the truck doing some diagnosis not drawing random conclusions on the internet.

No ***ing way oil would get into the cylinder thru the crack in the piston anyway. cylinder pressure is thousands of psi.

I have seen cracked pistons caught in time and the bore was fine. I have also seen them scored. No way to tell without a teardown.

Yes the engine can be pulled out the front but its a major waste of time to do it that way.
 

me2

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Could be a bad injector as well. If it was me i would be at the truck doing some diagnosis not drawing random conclusions on the internet.

How do you suggest I proceed with diagnosing it ? I have Auto enginuity.

No ***ing way oil would get into the cylinder thru the crack in the piston anyway. cylinder pressure is thousands of psi.

It sucks in during the intake stroke. Oil makes its way by the rings if the bore is messed up.

I have seen cracked pistons caught in time and the bore was fine. I have also seen them scored. No way to tell without a teardown.

I was going to pull the heads with the cab on. Is that the next step ?


Yes the engine can be pulled out the front but its a major waste of time to do it that way.

I'm garage less for the summer. I have to do this in my driveway. I've got a skid steer that I could use to lift the cab, but it would be a major pain to do so. Advice ?
 

sootie

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How do you suggest I proceed with diagnosing it ? I have Auto enginuity.

I'm not familiar with AE, sorry. If i was using IDS or FORScan i would start with a relative compression test. Then i would shut down each injector individually and see if the noise changes or goes away with a certain cylinder.


It sucks in during the intake stroke. Oil makes its way by the rings if the bore is messed up.

Bullsh!t


I was going to pull the heads with the cab on. Is that the next step ?

I never do anything cab on. Not worth the sacrificed knees and loss of forearm skin.


I'm garage less for the summer. I have to do this in my driveway. I've got a skid steer that I could use to lift the cab, but it would be a major pain to do so. Advice ?

Not sure. I use a two post lift and cab removal is done in less than two hours.
 

Strokersace

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I've done several 6.4 engine removal and installs cab-on. This is only because I do not have a lift. It's not terrible but the biggest complaint is having to be under it taking the bell housing bolts and engine mounts loose.

Someday I'll have a shop with a lift...
 

me2

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Thanks for the advice, guys.

I'm worried about further damaging the engine by turning it over/ running it.

What is the relative compression test going to tell me other than a cylinder is bad. The next step will be to pull the heads, right ? Why not just go straight to that ?

Am I wrong to think that the noise is for sure caused by a mechanical issue, like cracked piston, bent rod, valve train damage ?
 

sootie

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would suck to pull the heads an find out you just had a bad injector. Based on your responses, you arent interested in doing any diagnosis. Good luck with it.
 

sootie

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power balance test, relative compression and shutting each cylinder down individually to see if/what changes.
 

me2

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Got Auto Enginuity connected. This truck has sat for the last 5 months. Battery voltage was low. I have the charger on it now.

Pulled DTCs. Nothing significant. The alternator went out on this truck a while ago, so there were several CAN bus non communication errors and low battery voltage errors accumulated.


The only powertrain error code was
P0128 Coolant Thermostat (Coolant temperature below thermostat regulating temperature)

I ran a Key On Engine Off test. Got the following:

P0091 Fuel Pressure Regulator Control Circuit Low
P0003 Fuel Volume Regulator Control Circuit Low

Ran it again and it was clean. Ran it again and got the error again.

Ran the injector buzz test and they all passed.

The software can perform the glow plug test as well as the cylinder contribution test (engine running).

Are you thinking it is safe to run this engine ?
 

me2

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power balance test, relative compression and shutting each cylinder down individually to see if/what changes.

So you think it is safe to turn the engine over and start it ?

AE doesn't do the relative compression test. But it will do power balance and you can shut off injectors.

Any chance a glow plug broke off and is hammering on a piston ?
 

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