installed my rokktech sensor a couple of weeks back. at the same time i installed my quad zxt box. i made a good size diameter hole through the firewall for future mods(wiring offroad lights,etc) i did not plug the hole-so it's obvious that i can hear the sound of the engine in the cab more-so here is my question. while accelerating i can hear a pronounced pinging/preignition sound -(like the sound of a gasoline engine with too much carbon build up!) the sound may have been there before, but like i said i can hear the engine better with the hole in my firewall!. so, i backed off the senor alittle-but i do still have the pinging-maybe not as bad-but my mileage has dropped alittle since i backed off the sensor. if it is normal, i would like adjust the sensor back to the original position i had it at! truck runs great-no smoke,etc. any input? thanks guys!

 

I too noticed that, but only with the box on. I run the race box and when under slight acceleration I hear a pinging, or clattering sound, however when I turn the box off, it gets very faint (I can hear it, but very little). It really sounds like the injectors opening and closing. If I let off it's quiet, crusing, it's quiet, on the throttle hard I hear it, but it's only in one range that I can hear the "pinging, clattering" Mine really is more of a clatter than pinging though. I'm currious. I posted something about noisy injecters but haven't heard back.

Tom

 

mine truck is the same way- i can only hear it when i accelerate-briskly. truck is quiet while crusing,etc. mine sounds more like a preignition knock, than a clattering- but who knows-we may have the same sound-but describing it differently!

 

It may be the same noise. But like you said it's not all the time and when it makes this noise I turn my box from 60 back to 0 (no power increase) and it gets much quieter, which leads me to belive that it's the injecters making the noise. I did turn my tone ring back and it still made the noise which is why I believe it's only the injectors. Like I said with the tone ring and box off it runs great, only hear the noise with the box on. However it still made the noise with the tone ring stock and box on, so it's gota be just noisy injectors. Maybe somebody else has this, nobody has responded to the link I did. But mine only does it in this area, more gas, less gas, cursing no sound, however ther'es one spot where it is like a rattle, kinda odd sounding.

 

This sounds like the timing is too early.

BE VERY CAREFUL WITH THIS.

If you get the timing to early on a conventional pump line injector system, you'll get a knock. You won't get the same sound from a common rail engine because it is probably only the pilot shot that is early.

However, combustion temps and pressures will be very high with such early timing. The 3rd gen is a different beast.

If I was buying a box, I'd demand that the supplier publish the cylinder pressure diagrams/figures that they used to determine the optimal timing, injection rates and injection volumes. I also think they should leave the timing alone until the engine warms up.

Unfortunately, I don't think they've done any of this. To get cylinder pressure, You'd have to drill a hole into the combustion chamber.

Without cylinder pressure diagrams, tuners are guessing.

 

from reading some earlier posts- it seems that the pinging is normal on the 600/610 engines-due to the 3rd injection event

 

Loved that article about it. The only thing questioning me is that when I turn the tone ring back to normal it still does this. That's my only odd ball question is why would it do it when stock also? Also if I turn my box off the rattle disapears. Do you think this is still early, and I should leave my ring stock? Truck runs good with the tone ring moved, just has a rattling sound. I would say it's not detonation, or pinging, almost like a loose wheel bearing and it vibrates and makes a odd noise. I wish I could take one of you guys for a drive to "word" the noise correctly.

 

Going to turn the tone ring back tonight and see if it helps. I painted a mark on the tone ring and crank pully so I would know where stock is. I'm pretty sure it still rattled when the tone ring was in the stock position with the quad on 60. When I turn the quad off it gets very faint (hard to hear) I still think it's something with the injecters firing (or opening and closing) I'll keep you up to date.

 

"from reading some earlier posts- it seems that the pinging is normal on the 600/610 engines-due to the 3rd injection event"

The pinging sound I think you refer to is the fuel being injected into the cylinder and combustion of it starting BEFORE the piston hits TDC.

The 3rd injection event is happening very late in the power stroke. Cylinder pressures are moderate then. The combustion associated with the 3rd injection event should be nearly silent.

There should be NO pinging noise associated with the 3rd injection event's combustion.

DON'T BELIEVE EVERYTHING YOU READ ON THE INTERNET. THERE ARE A LOT OF WANNABES AND BS FLOATING AROUND OUT THERE. just because people do things and get away with it, doesn't make it right.

If you visit my gallery, you will notice that I did the math on the advance and did it precisely. There is a reason for that.

"Also if I turn my box off the rattle disapears. Do you think this is still early"

Yes. Tell your box manufacturer to retard the timing when the engine is cold. Cummins doesn't have to retard the timing the same all across the fuel/temperature map. They only need to retard it where NoX is problem. And that probably isn't when the engine is cold. Your box manufacturer should know that.

"and I should leave my ring stock?"

Your call.

"Truck runs good with the tone ring moved, just has a rattling sound."

That sound is high combustion chamber pressures. How high, I don't know.

"I would say it's not detonation"

Diesels NEVER detonate or they ALWAYS detonate, depending on how you look at it. Detonation is the pre ignition of fuel before TDC in an explosive rather than linear burn fashion. In a diesel there is no fuel in the combustion chamber before TDC, unless the rings or injectors are leaking. And the fuel does ignite in an explosive rather than linear fashion when it is first injected. But there should be no significant pressure build up due to combustion before TDC.

"or pinging, almost like a loose wheel bearing and it vibrates and makes a odd noise."

I don't like engines with odd noises. They get expensive.

My 05 3rd gen makes a pinging noise at about 20F for the first minute of operation at light throttle. It doesn't do it under heavy throttle and I don't give it heavy throttle when cold anyway. Once it warms up a bit, the noise is gone. I'd say I've got my timing advanced as much as I want it to be.

What you do with yours is your business, I just wanted to make sure that people understood what they were experiencing.

 

I've come to the conclusion that Superduty is who owns cummins, he know's too much.

My motor makes that sound mostly around the 1800 to 2200 rpm range, dosn't matter if cold or hot (although I do only get on it once it's fully warm) it's really hard to describe. I'm gonna take the video camera with me tomorrow so I can hopefully catch the noise if it still does it with the tone ring stock. I did measure how much the outside of the ring moved, however those measurements are home. I bored the hole out .060 and I'm not even hitting the bolts, so I did measure that corectly. If the noise is still there even with the tone ring stock do you think it's something with the timing in the box?? Whenever I turn the box off the noise gets very quiet. That's why I was thinking it's just more fuel going into the cylinder, or like you said higher internal pressures from the increase in fuel going into the cylinder. Well, tone ring is going back to stock. I'll let you know what happens.

Thanks for all the help superduty

 

"bored the hole out .060 and I'm not even hitting the bolts"

Those bolts and bolt holes were never designed to be a precise timing gauge. I don't know why people relied on that. Did you time your '72 gasser by the distributor location relative to the back of the carburetor ? Sorry, I don't mean to be facetious, but who said that if the timing ring was against the bolt holes you were OK ?

"My motor makes that sound mostly around the 1800 to 2200 rpm range, dosn't matter if cold or hot"

I don't think that is a good thing. But that is your decision.

 

i agree- superduty knows his stuff! but i am alittle confused superduty. you stated---

"The pinging sound I think you refer to is the fuel being injected into the cylinder and combustion of it starting BEFORE the piston hits TDC.

The 3rd injection event is happening very late in the power stroke. Cylinder pressures are moderate then. The combustion associated with the 3rd injection event should be nearly silent.

There should be NO pinging noise associated with the 3rd injection event's combustion."

what confuses me about your statement is- you said the pinging sound i am hearing is the fuel being injected into the cylinder,etc,etc
then you state there should be no pinging noise associated with the 3rd injections event. so is the pinging normal as far as the fuel being injected into the cylinder,etc???

 

" what confuses me about your statement is- you said the pinging sound i am hearing is the fuel being injected into the cylinder,etc,etc
then you state there should be no pinging noise associated with the 3rd injections event. so is the pinging normal as far as the fuel being injected into the cylinder,etc???"

ok... the pinging sound is caused by a pressure spike when the fuel starts burning before the piston hits TDC. Imagine this... piston going up, injector fires fuel and it starts burning a millisecond or so later while the piston is STILL going up. The pressure is tremendous because the piston is trying to compress an expanding gas. (The air/fuel mixture.) The force on the rod, crank, head, piston, wrist pin is all very high. It is not a good thing.

It is just like a gasser. Normal combustion is pretty quiet. But as soon as you get things too early, they get loud and pingy real quick. Normal combustion is quiet and too early combustion gets loud.

 

i now understand-thanks

 

My comment with the bolt holes was in agreance with yours superduty. I know of others who are boring it out all the way so it hits the bolts. I hear a lot of people say you can't add to much timing and that I'm sceptical of, which is why I bored mine out to the tolerance it should be.

I get the rattle either with the quad box off, or on, however when it's off it's a bit quieter, about half. It really sounds like a fuel injecter.

Tomorrow I'm turning the ring back to stock, and see what happens. I don't think my noise is a pinging, I think it's something else (which I hope is ok, and not bad) It's really really hard to describe the sound. If it does it with the timing ring stock and the box off, I'm not going to worry about it, cause it shouldn't have been anything I did. The part that gets me is it does it stock and when I turn the fuel up (box) it just gets louder?? So I'm not really sure what the noise is. I think it's all in my head