Cummins Engine Knock

[SpeedBump]

. . . My question is, is it normal to hear an "engine knock" kind'a like a gas engine when it is pinging from too much advance? This sound goes away when accelerating, but comes back when driving at a constant speed.

Exactly the same syptoms as mine!



I just picked up my '05 at the dealer tonight. When I test drove it I heard nothing out of the ordinary. Salesguy takes the truck somewhere to fuel-up while I'm signing the papers and then I leave. I got about a mile down the road and I noticed the pinging, clattering noise. My 1st thought was the guy filled it up with a tankful of gas instead of diesel. By the time I turned around and got back to the dealer it was closing time and the salesman was gone. Another guy listen to the noise and we cranked up another '05 sitting on the lot. My truck defintely has noise coming from somewhere.



Anyway, sales manager say's drive it for a 100 miles and see if it quiets down. Guy's I don't know what to do. I really feel like giving the truck back to 'em and saying no thanks.



Any ideas?



Thanks!



SB

 

[tschwab]

My '05 has/had/still has sometimes, the same symptoms. Since the TSB reflash 18-037-04 things have improved. I have also been running Stanadyne Performance Formula with each tank and that also seems to help. I still think we are talking about two separate things here, diesel clatter common on 3G's which takes some getting used to after coming from a 2G and a 12V and those that are having injector problems. I would watch my MPG's closely, which could be an indicator of a bad injector.



I think the sound has a lot to do with pilot injection for emissions on the '04. 5 and newer trucks which have three injection cycles, if I remember correctly, the 3rd injection cycle only happens sometimes... under hard acceleration or? Which could also explain "WHY" we only hear this sometimes and not all the time.

 

[BHolm]

Seems like the diesel pick-up market today is a big gamble. This push for big power and more stringent emmissions controls at the same time may be to blame. Looks to me like the GM trucks are somewhere near a 20% failure rate on injectors, that is one in five the Fords... . well the 6. 0 is still not right if you ask me, and now the CTD injectors seem to be failing far more often than they used to (which was pretty much never!).



So far I have been pretty lucky, niether of my '03s have any problems and they have 70-80k miles each on them. Fuel may be a concern. My work trucks (the '03s) are fueled from my 500 gal tank with its own regularly changed filter. The place I buy the fuel from is good about changing the filters on their tank and on the truck that makes the deliveries. On my '05, that gets fueled multiple places I use Redline additive for piece of mind.



So... you could unload the truck but, unless you switch to a gasser, your experience may be par for the course. I think I might see about getting it fixed. If they can't do it in three tries then lemon law it for a replacement. Keep a copy of all the work done. Good Luck

 

[joeyou]

Exactly the same syptoms as mine!



I just picked up my '05 at the dealer tonight. When I test drove it I heard nothing out of the ordinary. Salesguy takes the truck somewhere to fuel-up while I'm signing the papers and then I leave. I got about a mile down the road and I noticed the pinging, clattering noise. My 1st thought was the guy filled it up with a tankful of gas instead of diesel. By the time I turned around and got back to the dealer it was closing time and the salesman was gone. Another guy listen to the noise and we cranked up another '05 sitting on the lot. My truck defintely has noise coming from somewhere.



Anyway, sales manager say's drive it for a 100 miles and see if it quiets down. Guy's I don't know what to do. I really feel like giving the truck back to 'em and saying no thanks.



Any ideas?



Thanks!



SB

My Cummins contacts (their service engineers) say the "pinging" sound is normal and is a function of the pilot injection timing to meet 2004. 5 emissions. I wouldn't be too concerned unless you hear a definite knock. My 2004 seems to have gotten a little noisier since new, but not knocking. I am beginning to think it may be due to the colder ambient temperatures. The reason I think this may be the case is that when the truck is first started in the AM it is very quiet while the grid heaters are on. I bought my truck in the summer when the ambient temps were high and when I think back, I believe I began to notice the change in sound when the weather started getting a little cooler... just a possibility.

 

[Spooled-up]

I noticed that the truck takes 2 to 3 seconds longer to start vice my 2000 24 valve, but no white smoke that I can see.

Someone correct me if I'm wrong, but it takes longer to start because the crank position sensor has to send the signal to the ecm before it can electrically fire an injector which takes a second or two. The older 24v's would fire as soon as the injector built enough pressure to pop off which would take just a fraction of a second.

 

[tschwab]

Someone correct me if I'm wrong, but it takes longer to start because the crank position sensor has to send the signal to the ecm before it can electrically fire an injector which takes a second or two. The older 24v's would fire as soon as the injector built enough pressure to pop off which would take just a fraction of a second.

You are exactley right on that.

 

[shendren]

my engine "drones" kind of like an aircraft engine. ?? i like the 2nd gen sound much better.

 

[EConnelly]

EConnelly,

I'd be willing to bet a case of beer that you have one or more bad injectors. Keep on them. The mileage reduction that you have experienced eliminates the "all in your head" "can't duplicate customer complaint" "computer says everything is good" arguments IMO.



Dave

23000 miles on the truck now, I finaly got a Dodge mechanic to listen to me and truck at the same time. Like always, they go down the normal list of reasons and causes of noise in the engine. This time he acknowledged that it is making a little bit more noise than normal comparing normal idle to dropping it in drive. In drive it really rattles. He did the kill test. I think he started at the number one cylinder and found the noise at the #2. I think he probably stopped there and didn't go any further. He replaced the injector for the #2. It did cure allot of the noise but I am still getting intermitent rattle. I think there is still another fuel injector that is bad.

 

[JCleary]

My truck has some injector noise at partial throttle as well. It does it at light throttle, when maintaining speed or releasing the throttle to shift especially when it's cold outside. There is definitely a diesel rattle coming from under the hood. It's not the same noise as a bad injector makes, I have heard that too (On my PSD).



I do believe it's partially related to fuel quality. I've filled up at one particular Chevron, and I thought my truck was having issues. It got really loud. After running that tank down, I filled up at another Chevron, and all was back to normal. I do use Stanadyne at every fill-up, and my truck is running great with 20k on the clock.

 

[GColeman]

It seems to be normal for 04. 5 trucks. Mine came on at about the 8K mark and has remained with 18K on the clock now. If its runs good, ignore it. If you have any white smoke issues or rough idle, it is probably a bad injector. It seems that all of the 04. 5s have gotten a little noisier after a few thousand miles.

 

[RPotter]

It seems to be normal for 04. 5 trucks. Mine came on at about the 8K mark and has remained with 18K on the clock now. If its runs good, ignore it. If you have any white smoke issues or rough idle, it is probably a bad injector. It seems that all of the 04. 5s have gotten a little noisier after a few thousand miles.

I agree. My 04. 5 now has 16K on it, and I have exactly the same experience. No smoke at start or ever, unless I really stomp on it, and idles smooth as silk, so I don't believe it's an injector either in this case, just sounds different. Goes like a bat out of you know where, so no complaints here.

 

[RMarkey]

This is all a little disturbing! I read these posts and wonder if I have a Real problem, or just a moody truck. I was getting and avg of 11. 7 to 12. 5mpg so I had the comp reflashed. Since then I haven't had a comparable tankful since, I'm not sure, but I'm pretty sure I'm getting a little better mpg. I still have white smoke on startup, worse maybe than before on some days, and it seems to sound rougher than it did before. It still gets, but still no smoking tires. I drive all gassers except for an old 94 Ford diesel that clacks so loud you can't think (not including all the Kenworth/Cats I drive all day long for work, diiff animal there). I Think all the noises my truck makes are normal, but sometimes I worry! Should I be thinking about injectors or just ignoring the "noises" and enjoying my truck?