I found a thread from 2011 on this but rather than resurrect that one I'll start a new one.

My truck will intermittently sound like an old 7.3 clattering away. It's done this for some time now. If I accelerate briskly it'll quiet down. When I first got it (used) it was quiet as a church mouse. It seems to normally be during the 1st 20min or so of a run. Weather and fuel doesn't seem to be a factor nor does it matter whether I have additive in the tank or not. My truck is a May '10 build 2011 with about 60k miles on it now.

Is this normal? Anybody else with the same 7.3 noise from the 6.7?

 

My opinion is it's normal, I don't worry about it. My May '10 build does the same thing at low speeds, such as leaving the subdivision in the morning. I can tell you it is not near as loud as it sounds when the turbo isn't working!

 

My 2015 is noisier under light acceleration. Press on the on the skinny peddle some and it goes away. 2011 was the same way.

Now that my 2015 has near 20,000 miles on it, I think it's a bit louder than when it was new. I put this down to the cabin having some age on it more than the actual engine getting louder. That's just a guess though.

bruce...

 

Not quite sure this will help. I have a post going on about loss of power and excessive noise my dealers diesel mechanic after finding nothing wrong with my 2016 truck recommended Hot Shots fuel treatment extreme ,can't begin to tell you how quiet the engine is now and how easy it starts and endless power on a second tank of fuel already still running great you can give it a try good luck. There's an ongoing discussion about deposits left in the injectors due to the high pressure fuel system returning the fuel to the tank and cooking it don't know how much I believe this considering I only have 16000 miles on my three month old truck, all I can tell you is what a difference we'll see how long it lasts take care

 

My August '10 build truck has exhibited the same behavior since new. When cold, after pulling away from a stop, any significant acceleration seems to "shut off" the pilot injection. I assume it's a function of the programming to provide the power I'm asking for. Once warmed up a bit she's quiet as a mouse. The diesel clatter seems unaffected by where I purchased the fuel, or if I put in an additive, and seems to be related only to the outside temp or temp of motor (coolant/oil temps). Colder the motor, the more clatter she makes if I get on it.

 

Mine makes the clatter under light pedal, if I accelerate it smooths out and quietens. It will also come and go in an instant when just cruising along at in town speeds, does seem to be more so when the engine hasn't warmed up.

 

Pretty sure it's the HS Diesel Extreme I tried in the past. They sent me a jug for free to try out and I used 1/2 of it, I'll look for the jug and try it again on the next fill. I've also used the Royal Purple additive in the past. Neither seemed to make a difference as I recall.

 

My truck does this all the time. I have no idea why but it seems like a valve opens and closes for some reason and the engine just sounds different. I don't really feel any difference, just sound.

 

Ditto. Sounds just like the pilot injection video when the engineer flips the switch on and off.

 

So, the "diesel clatter" is What? I don't remember why diesels sound the way they do which is embarrassing, and therefore, I don't know what this pilot injection does to silence the typical diesel rattle. I thought that this clatter is a result of the intake and exhaust valves being opened and closed via internal air pressure as opposed to a gas engine using a cam.

 

Think the clatter or diesel noise is from the power stroke when it compresses and fires, multiple injections reduce the noise as far as I know.

Seems like the noise I have is just a somewhat normal thing

 

The diesel "clatter" is created by the injection of a volume of fuel at very high pressure. The pressure must be higher than the compression of the air inside the cylinder. Pilot injection is the use of a series (up to five) of injection events per firing, thus reducing the loud noise associated with one long injection. The valves in your Diesel engine are opened and closed by lobes on a camshaft, just as in most gasoline engines.

 

I think that the clatter can come from low cetane fuel. If the pilot injection doesn't ignite because the cetane is low, then the ignition will happen with a larger amount of fuel a bit later causing more noise.

 

Since when did the noise associated with a diesel, aka diesel clatter, not be from the pressure wave?

Pilot injection (1 or more pre-main injection cycles) reduces the intensity of the pressure wave, ramping it up instead of all at once.




This video came out about a year before the 6.7 landed.

 

Mine gets better with summer fuel, it's worse with winter. Been thru 2 winters now and the same thing happened. I can tell when winter fuel hits the pumps and when summer fuel returns. Truck is quieter the past couple of weeks.. and sure enough when I look at the fuel the greenish tint is back. It's as clear as water during the winter.

Personal opinion - it's normal. I notice mine more at part throttle than full throttle.

I, too, think it is partly fuel quality related. (or maybe temp relatled?)I don't have any scientific studies to prove why it's quieter in the summer than the winter. Although only two things are different, environmental operating temps and fuel...