Hey guys, how common is this knock issue and is cummins addressing the issue. I thought these cummins were bullet proof? I am leaning (real far to the right) toward a ctd. I already have a 5.4 turd with piston slap. I don't want to fall into another engine issue. What gives?

 

Knock??? Mine will have a ticking when cold.. No knock tho...

 

With 847 miles so far, my 2005 has the normal underlying "clatter" noise. Mostly noticible when accelerating. Not really a knocking sound.

 

Got 28 K on my 04. No knock to speak of. Just normal cummins clatter that all cummins have. Is the knock you are refering to injector knock? If so DC has been replacing injectors that are bad. However I do not believe it is a very common problem and most folks that have had the issue (and post here) seem to have had good responce from DC.

 

many people new to diesel engines report a "knock" which is commonly confused with the clatter x_ram-on_x mentioned. this noise is normal. mine does it, as does every other 600 i've listened to. my experience with the big cummins engines has been that if you have an injector problem, you will know it.

 

Mine has the Injector knock when warm. At idle and up to 1500 rpms it sounds like a piston is coming through the block and there's a slight vibration in the transmission **** and steering wheel at idle. They've already replaced #3 injector at 17k miles and truck is going back in this Monday for another one at 22K miles.

To find a bad injector is a lengthy process. They have to disconnect an injector one at a time, run truck until warm and see if the noise goes away. Once they find the bad one, they then have to switch it to another cylinder and see if it still makes noise to verify it's the injector and not a piston slap. All this had to be coordinated with STAR for the injector replacement. So, plan on having truck in the shop for about a week!

 

At 10,000 miles, mine has a knock. I am sure it's an injector but dealer says normal. It makes my eng sound bad. My question is if ok, why only one doing it?

 

rossn2,

If I remember right our trucks came off the line about the same time. First week of October last year. I have already had 2 injectors replaced and this past Monday I had to take it for knocking again. This will be the third one! I wonder if we were part of a bad batch of injectors? The diesel tech just puts on the DRB tool and turns then off one at a time while I hold the brake and ease out the clutch to make it knock. When he does the power test all are around 100% except the bad one and its at 91%. They then call STAR and order one and call me when it comes in. Usually two weeks. Just thought you would like to know and good luck with yours.

 

Mine with 16K doesn't "knock" but it does knock as it should. It's a diesel. An injector knock I've never had so I don't know what that would sound like. Wonder how may 1st and 2nd gens. have a "knock" but can't be heard because of the fuel delivery systems?

All diesels make quirky noises. When its cold out, they're more noticable. I figger it must be normal since some of these diesel powered trucks I drive have 700k+ trouble free miles.
Just my .02. Your's might be worth more.

Alan

 

My 03 HO makes a lot of old-school clatter on a cold-start and has since the day I brought it home. I assume it's normal. It's very consistent and as soon as I get a little boost after leaving it is clatter-free.

Andy

 

Jerry R,

I have an 04 and it was built the 2'nd week of October last year. I had one injector replaced at about 20k miles and am taking it back as I have another bad knock again. A while ago I posted a couple recordings over at TDR of what my truck sounded like both before and after the injector replacement.

http://www.turbodieselregister.com/f...hreadid=108510

Dan

 

CADan,

Yes, I remember listening to them and mine sounds the same way. When you have a bad one it stands right out. So yours was built the second week of October. Thats very interesting. Mabe some other folks who have had injectors replaced will chime in when there trucks were built.

 

Mine seems to make less noise since getting a few miles on it, as others have said it seems like it starts getting broken in at 25k miles. Using Stanadyne has helped, espcially when it's cold, and also using a synthetic blend of oil has helped. I can tell when it's fully warmed up as the noise and clatter quietens down.

 

1sttruck,

You don't have the same issue as us with the injector knock. With a bad injector, the noise gets worse as the motor comes up to temp and no amount of Stanadyne will fix the injector.

Dan