Welcome to DieselPlace

A video of the noise can be helpful for other members

 

Here's the video, my wife described it as someone tapping on a glass cup.

 

Remove your serp belt and briefly run the engine at idle. Does the noise remain?

 

Ok, took belt off and started, no change in noise. Forgot to mention it gets louder when engine is warm. :/

 

Are you using any fuel additive?

 

PS diesel kleen for a while, then I heard about 2 stroke oil to help the injection pump, so I switched to that. Although this was all way before the ping noise started. I put around 1oz per gallon....Can it cause pinging problems?

 

No it shouldn't ping with additive.. The additive is needed for the 6.5L fuel system using Ultra Low Sulfur Diesel.

 

Ok cool, well I'm glad I've been adding something then.
Been poking around at it all day and couldn't find anything interesting, cracked each injector line and didn't see much of a change from that. Cylinder back one from the front passenger side maybe makes the most difference? but very hard to tell.

Could it be the turbo wheel hitting the side of the turbo? There was some play in it, not a ton. I also noticed a slight rattle right when it starts up, right after cranking, coming from the same general area.

Oil pressure is 20psi idle hot, 50 psi going down the highway.

 

Make sure the injector lines are not touching anything and the rubber line isolators are in place and secured to their mounts. I really did not hear anything unusual in the vid But it may be my little speakers. Sounds like my 6.5. They are a very noisy engine.
Usually after injector replacement and you have a noisy injector or 2. You have to drive around for a while to work out air that may be trapped in the injector.. Have you driven it much after injector R&R?

 

Yeah the noise is kinda hard to hear on camera. Lemme try to upload a new video from a different angle. OkDually - Is the noise noticable to you from the vid? I would be happy to hear that I'm just being paranoid haha.

I've driven about 150 miles since the injectors were replaced, all highway. On the first test drive I tried flooring it a couple times to get any air out of the injection pump as well from the fuel filter replacement. Runs great minus the noise. Lots of power for a 6.5 and only a slight puff of black smoke on acceleration.

It does look like the rear two lines once rubbed as there is some rust in between them, but they aren't touching now, and the rubber piece is holding them apart. I tried lightly prying them around while the engine was running and no change in the noise.

Thanks for the suggestions.

 

I can barely hear the noise in the video. It sounds like a metal on metal ping

 

Yep that's it. Lot more noticeable in person.

 

Watched your video. The sound has a higher frequency resonance which leads me to believe it's from something large or hollow. I'd explore your turbo some more. If the wheel was hitting the housing there would be obvious sign. Does it get louder or change with rpm increase ? Even gradual for example 1000-1300 rpms?

 

Yeah I agree it sounds like something in the turbo. It does speed up with rpms, but after about 1500 I can't hear it anymore. I'll see about pulling the turbo and taking a look in there. It's weird though since it makes boost just fine and spools up.

 

So I pulled the turbo and didn't find anything too interesting. Something that concerned me though is there was a lot of cast iron chunks coming off of the turbo exhaust inlet flange, some broke off in my hand (attached a picture)...So this may have been sucked into the turbo? I scraped everything off as good as I could. Also grabbed my boroscope and took a look at the turbo wheel, didn't see anything missing or any dents/cracks there.

 

Not sure if it attached

 

Starter heat shield loose?

 

Good one, forgot about that, but unfortunately I just checked it and it's solid.

 

I'd grab a mechanic's stethoscope and poke around to narrow the noise location down

 

I'll have to invest in one... I used a metal rod as a stethoscope but didn't really find anything. It kinda seems to line up with injectors firing but cracking each line on the passenger side didn't turn anything up.

 

Just for grins, remove the turbo brace and see if it changes.

 

For listening purposes try a section of rubber hose and if you like something to plug up the off ear. I use 5/8 heater hose and even garden hose, the sound is kinda hollow but you can place it right on right on metal without transmitting unwanted sound.

 

Thanks, I'll see if I can make one

What do you guys think about that metal stuff I found in the turbo?

 

Cast iron flecks in the exhaust elbow shouldn't cause this as it gets blown to the mufflers. There could be something in the turbine volute, taking the turbo off would be the only way to inspect

 

Definitely leaning toward something like that. Today after driving for about an hour I saw some oil dripping down the side of the turbo. Also last week when I removed the turbo I saw lots of oil on the intake side as well. It doesn't seem like the truck is burning it though, and the CDR valve is new acdelco.

 

Anybody have any thoughts on the turbo?

 

i have a similar noise that comes and goes and is somewhat heat related and was more pronounced when I first rebuilt my motor.... if the timing of the noise as turbo related I would guess it would be either much more frequent or even solid as the turbo is spinning at a much higher rpm as the motor. My guess for me is a dodgy/loose precup and I will not know untill I swap heads.... which is no time in the near future. Hopefully someone can pinpoint this as I know I am not the only other person that identifies with that sound!

 

That's interesting, I never thought about that. If a precup was loose wouldn't it immediately hit the piston and destroy that cylinder/head? I have good power and no other noises. What did you do to remedy your noise? But it definitely sounds like it's coming out of the exhaust or resonating through the exhaust.

Since it goes away at higher rpms maybe the turbo wheel stabilizes as it spools up, which would explain the noise only at low rpms/idle?

I'm clueless otherwise .....

I tried the stethoscope and it seems loudest around the exhaust manifold or below the turbo area but seems impossible to pinpoint.

 

I think what confuses me the most is that it started right after changing the injectors, yet I can't pinpoint which if any injector it's coming from. Maybe it'll go away on its own as the injectors seat?