Isn't a little engine knock normal for the 600?

[MMead]

A while back everyone seemed to be saying these 600 motors just had a little knock/ping sound to them and that it was normal. Now everyone is talking about getting injectors replaced.



If my motor has a moderate knocking sound under no load around 15-30 mph is this normal? How many other people have the same sound?



Hopefully the earlier posts were right, and this is just a normal sound for these diesels to make. I've got a feeling if I took it to my five star dealer he would tell me the spark plugs must be fouled.

 

[rbattelle]

I've got a feeling if I took it to my five star dealer he would tell me the spark plugs must be fouled.

I've got a feeling you're right.

Anyway, some knocking noise is normal in a diesel. Generally what people are seeing as a real indicator of a problem is a loud knock at idle up to around 1200 RPM under small load and light throttle. I would say you're just fine.

Remember, if the engine explodes before 100k, they have to give you a new one.

 

[DavidC]

Not necessarily. Remember the 2nd Gen 53 block. This Kncking you guys have makes me wonder if there is another secret they know about and hope to make it past warranty.



Dave

 

[tschwab]

I have got to believe a little knocking/ping is normal as my truck ('05), my uncles ('04. 5), my dads and my other uncles (both '03's) all have it. Uncle with the '03 has towed cross country with a 10k+ 5th wheel has over 50k miles and 90% of the trucks use has been towing. We all have the 48RE and have had NO problems.

 

[nickleinonen]

at idle, if you feel the HP lines going to the injector from the rail, you can feel the injectors pulsing. if there is no knock, it will feel real smooth, and if it is knocking, well you will feel it... my #1 has developed a knock that is pretty noticable [if you feel the line, you can put the knock in sync with your hand and your ear] and my #4 is just starting to pulse the HP line more than the others... not worried about #4 right now, but i am going to get the dealer to look at #1. got 2 years left of warrenty so i am in no hurry though. .

 

[MCornwell]

My #1 line has "Pulsed" from day one. . its normal, the #1 line has no hold-



down.

 

[CBrittan]

My engine knocks frequently, but I drive my Detroit 500 hp 12. 7 ltr engine 2800 miles a week and at 643000 miles it knocks too, and always has. I think our new engines are so quiet now, much less ambient noise compared to previous generations, we can hear the knock, and much of it is just typical diesel noise. If an injector goes bad, pretty safe to assume you will know it!

 

[Gary - K7GLD]

AHHhhhh - I see rationalization is still alive and well...



C'mon guys the REASON for the new engine design was to ELIMINATE those kinds of noises - if yer still hearing them, SOMETHING isn't right! Ya PAID for a quiet engine - don't ya think ya really should GET one?

 

[CBrittan]

Come on Gary. Did you ever... ever hear any diesel... any make... any model, any size... whatever... that did not make any noise? This is commonly called 'diesel knock' or have we forgotten how it is that diesels are different than gasoline engines.

 

[JVolpe]

I have to add my 2 cents. I have about 9K miles now. About 700-800 miles ago I started hearing a noticable TICK at idle, this is still there and easier to hear. About 300-400 miles ago I started hearing a noticable KNOCK at idle and thru low rpms. The truck is running fine and dont really hear anything after about 1200rpms. These noises might be normal, but they were not there the first 8K miles(4months).

 

[Gary - K7GLD]

"Come on Gary. Did you ever... ever hear any diesel... any make... any model, any size... whatever... that did not make any noise?"



We're not talking here about just "any" noise - or "any" engine - but one specifically designed with a fueling system and computer to ELIMINATE or greatly diminish what was formerly considered "normal" diesel combustion noises. Think about it if these knocks WERE "normal", why are only a FEW cylinders exhibiting that knock - or only one? If it was "normal", wouldn't ALL the cylinders be doing the same thing - and wouldn't pretty much EVERY truck do the same thing?

 

[thames1948]

Thats the same problemI have with the knock, it wasn't there for the first few thousand miles. When I took it to the dealer the tech told me that number 1 knocked because of distance it is in line with others. Said it's normal. If I got good mpg's it wouldn't bother me, but I don't so thats why I wonder if its a bad thing.

 

[R.M.THOMPSON]

Sound and noise are two differant things , period. They may only be dicerned by the ones comparing them(like an opinion),so here is my story and I'm sticking to it !!!! I had a 03 555 and it's sound was smooth and consistant. Once in a great while something sounded differant(tick,clack,slight knock,etc), decibel level as compared to a 2nd gen was much less,but I would not say the 2nd gen was "noisy" by any means,just louder and differant. The occasional sound went away in short order and I just chalk it up as feul/temp/wear related or something like that. Not enough to make much more than a mental note in case it repeats itself to the point of/or get louder and becomes objectional(NOISE) Now,heres where the recent arguement takes root in my opinion. I have a 04. 5 now and it has two distinct issues as do many others and I believe that something must be done to eliminate them in order to retain this truck in its current form... ... ... OF SOUND LEVEL AND FEEL. The first issue is random light knocking NOISE that occurs with an extra engine related VIBRATION pulse that will set up a cycle on things like the drivers door open about half way,and other stuff like coffee , loose change ,tool bag under rear seat ,etc, and a very distinct exhaust note as if a cylinder is overfueling to a small degree. Now to beat the band if one is to use a infrared thermometer and take some random samples of exhaust manifold temps immediately after a load has been removed from the engine you may find that this rouge NOISE/VIBRATION can not always be from the same cylinder, or not be there at all and the engine has a good SOUND/FEEL The secound issue is the pinging and my opinion is that it is wholesale NOISE , wich has no distinct pattern and is objectional to me in a very big way. I started off in large diesel driven ship engine rooms at 17 years old and now at 45 work in multi-million dollar air conditiong/cooling plants of hospitals and manufacturing and have relied and been trained to use the bodies senses as well as raw data to provide reliability and safety to the operation and personnel of these facilities. In closing there is one thing that OUR arguement has been dancing with and it is how to explain the abnormal NOISE AND VIBRATION issues with our trucks to each other and DC and not be summarily dismissed as hypocondriac's and told that what we have been experiancing is normal diesel SOUND AND FEEL.

If you have made it this far you probally don't think this is a rant and feel free to get in touch with me fore more steps to take in this issue that I feel is a amalgomation of symtoms in wich we have not found the true problem.

Sincerely ,Mark T.

Can't find spell check

 

[Georgia Cracker]

What bothers me, and perhaps others, is not that there is a small noise (knock, ping, tick), but that the noises are not consistent across engines. I had a 2004 F250 that I sold because it had a knock that was noticably louder than other 6. 0 engines that I listened to. It was annoying.



If a noise is "engineered," a predictable characteristic of design contingencies, then the noise should be consistent across all cylinders and at all times. My Cummin has a knock-like sound at idle that goes and comes. The dealer would say that it is probably a characteristic of the fueling distribution or sequencing. If so, why doesnt Cummin fix it.



On my F250, it was common knowledge that #8 injector caused a knock, "because it was the last in line to get fuel" which I assume caused some pressure related anomoly hence an unusual sound.



Well, dammit, fix it. We get all these diagnostics that seem to have nailed problems without factory fixes. I dont think any manufacturer fixes anything until they think it influences market share. Cummin die hards will buy a Cummin for its durability in spite of the annoying but fixable noises.



I guarantee you that if there was a competitor MB motor made in Germany that had the same durability without the noises, Cummin would all of a sudden make the changes necessary to elininate injection related noises.



If you are a good, home grown engine diagnostician, you listen for the errant noise - the descriminably different sound which tells you there is an existing problem condition. Thats what everyone on this board is doing when they complain about this or that noise. If all 8 cylinders knocked the same way, we would accept that hormonic and move on. If 7 knocked and one was quiet, we would be worried about a problem.



The fact is that Cummin can fix all of this. Ask yourself why should they?

 

[DavidC]

Someone (Chrysler/Cummins) will fix it 1 day after your warranty has run out.



Dave