Failed injectors?

[Mopar4u]

Does anyone know what is failing on the 04 and up injectors? Is it mechanical or electrical? Have had three fail and another starting too. DC won't warranty anymore. Can anybody rebuild these to stock and make them last. Any info on how many failures of injectors. Dealer says they are replacing at least a dozen a year. Thanks.

 

[CStraface]

Just get some aftermarkets in there... .

 

[PRawls]

Are they the 04's or the 04. 5's and up?

 

[PBrauer]

Does anyone know what is failing on the 04 and up injectors? Is it mechanical or electrical? Have had three fail and another starting too. DC won't warranty anymore. Can anybody rebuild these to stock and make them last. Any info on how many failures of injectors. Dealer says they are replacing at least a dozen a year. Thanks.

They're leaking. Sometimes just a little. Sometimes enough to drop rail pressure and affect the rest, and sometimes catastrophic (stuck wide open, which happened to a friend of mine's '06, less than 5K miles, absolutely zero mods... brand new truck with a crankcase full of fuel).



The very first one I replaced ohm'd 10x all the others. The rest have just been "best guesses" by using a home made, in cab stethoscope. It always gets better when I replace one but never has gotten "right".



I just posted this in another thread but here's the p/n for the new, revised injector for the '06 CR, might be the same for yours but I don't know.



Cummins Part Number:

4940051-NX

$420-$440 is a good price

$450-$475 is a fair price

"NX" means New Exchange.

They don't have enough cores to sell rebuilts yet, I guess.



Don't go to a dealer anymore. If they have old rev's on the shelf, and you're out of warranty, they're bound to dump them on you while pretending to give you an "excellent price" on parts (that STAR won't let them use anymore).



Go to a cummins dealer but not a parts distributor for parts. Dealer can give a break on parts (to retail) but distributor can't. Sometimes the dealer can sell them to you and you can pick up at distributor.



Those big truck shops along the highway are now your best friends, as they always deserved to be.



I've bought six now. All will be new when I get the last two in.

Good luck.



Oh, and a dozen a year at a dealer would be very low. Word is they've stopped trying to isolate individual injectors and instead they're replacing all six at once now, at least under warranty. Must be a HUGE relief to the poor tech's that used to bounce one around until he found the bad one... only to see the truck sitting out there a week or a month later with another bad one. A good tech can replace all six in 1. 5 - 2 hrs. Isolating can take days (swaping, driving, swaping, driving, etc. ) unless they have all the gadgets to truly isolate flow and return which is still half a day at best.



Tips (nozzles) can be inspected and/or replaced but I've heard that the revision is a ball, possibly up high in the body, probably an assembly seal, that they are chrome plating now due to unexpected wear (all rumor, no good references). If you have your current ones tested, make sure you go/send to someone who can fully bench test them when they're done.

 

[TowPro]

Wonder when this 06 revision injector made it onto the assembly line? My truck build date is 12/05, so motor would be even earler on 05

 

[robmints]

Thanks PBrauer. When my truck was brand new it got between 16-18 mpg empty, combined. I expected it to go up a little. Now it is suprising when it gets 14. It seems to run fine, but this is my first deisel. I don't see any smoke, white or black, at start up or under load. And the oil level stays at the correct level and smells fine. It does fail to start the first time once in a while. But I still feel it should get better mileage. From reading others here I was chalking it up to "winter blend" what ever that is. How would someone know if they had an injector problem?

 

[coobie]

Does anyone know what is failing on the 04 and up injectors? Is it mechanical or electrical? Have had three fail and another starting too. DC won't warranty anymore. Can anybody rebuild these to stock and make them last. Any info on how many failures of injectors. Dealer says they are replacing at least a dozen a year. Thanks.

I have around 50,000 miles on my 2004 and have not had any injector failures. I have run fuel additives (stanadyne PF and Primrose 405-409)since day one of my truck being new. I have heard good things about Don m. flux injectors. coobie

 

[PBrauer]

Wonder when this 06 revision injector made it onto the assembly line? My truck build date is 12/05, so motor would be even earler on 05

Towpro,

I think mine was 10/05. My buddies catastrophic leaker was on a truck he bought less than six months ago. I need to ask him if they replaced them all or not, and his build date. The worse thing about his was it (fuel in oil) damaged the turbo bearings, even though he never left town. He actually had to take it back and point out the obvious rattle. He had one stick wide open. He even overflowed oil. He also owns his own shop and wasn't too happy that they didn't notice that Turbo rattling away. At least he was under warranty.



robmints,

I wouldn't really count on anyone to properly troubleshoot/isolate them individually, except a well equipped performance shop or a fully equipped fuel injection shop. Might run around $300 for them to set up an run all the flow tests. Bottom line, if someone only has the truck in a shop for an hour or so, they haven't really checked much.



It's all about measuring total flow (from the rail), total "return" flow (that odd fuel line that comes out the back of the head), then determining which injector(s), by blocking one at a time, reduces flow and/or return flow more than the rest. They can leak at the nozzle, the return port (a little hole in the middle of the body) or at the pass through tube where it seats into the injector. In fact, the very first thing anyone should do if they suspect high return is to simply re-torque all of the pass through tubes.



BTW, mine never has smoked much either. Eventually it started smoking for a few minutes (max, sometimes only seconds) after a long idle. I think it's fuel boiling off in a cold exhaust (leaking nozzles). My exhaust has had a very fowl smell since it was brand new. I expected it to go away but it only got worse. I honestly think I've had at least one bad one since it was brand new.



I'm no expert, I just ask a lot of questions. Don't take anything I say as gospel. Having said that, I do think a lot of the CR driveabiltiy, performance, and even trans shifting problems people are having are injector related. If anyone is still under warranty, I'd recommend pressing hard at the dealer when/if you suspect injectors. It's only a few hours labor to replace them all, and they keep the cores, which they can rebuild properly and return to stock. If this was considered a safety issue, I'm sure there would be a recall.



There are people out there getting 20+ mpg while some of us are at 12-14 under similar conditions. I guess those EPA ratings only count on paper. The truck already knows its rail pressure. If they came up with a way to measure return flow, the truck could tell you when you have at least one suspect injector. A good design could probably even tell you which one if it's going "though" the injector. Wouldn't it me nice to get a code?



Remember, it's a Common Rail. It's practially useless to crack the lines to individual injectors for testing, not to mention dangerous. You just drop pressure to them all, no matter which one you crack. Lifting a lead (wire) to one at a time might tell you something but this truck idles better than you'd think on 5 cylinders, so finding the one that makes it the "least worse" is hard (been there, done that, a couple times). "Contribution" from a scan tool is great for finding blocked/clogged injectors but practically useless for finding leakers. The only way to really figure things out is to PLUG them, one at a time, then measure the change in flow from the rail... and through the return. Not complicated, just labor (and equipment) intensive.



A good shop can not only tell you which one's should probably be replaced now, but which ones will probably need to replaced next. A couple MPG's will cover that $350 bill in no time. That's less than 150 gal's of fuel. I should have gone that route in the first place.

 

[Mopar4u]

Thanks for the info. Too bad about the 06 and up still having troubles, was thinking about trading to an early 07. Dealer doesn't want to do the work of diagnosis even if I pay. Can't figure that one out. Wish I could stick my 98 12 valve in this truck!!

 

[robmints]

Could someone with doubts put the $350 towards buying improved injectors of some sort? Are enough of these things failing to make replacement a reasonable consideration? I sure would like to know where my mileage went, besides down. PBrauer, I would hate to end up chasing my tail like it sounds like you have been having to do. Thanks for your help

 

[OPoole]

If any you guys need a new set of 04. 5 and newer injectors i have a new set of 6 no core. There in mopar boxes

 

[BradyWilliams]

What usually fails is the checkball seat in the control B&P assy. It gets eroded from contamination as small as 5 micon particles. Once in a while we see cracked injector bodies or nozzles. Thanks

 

[RGramlow]

Thanks PBrauer. When my truck was brand new it got between 16-18 mpg empty, combined. I expected it to go up a little. Now it is suprising when it gets 14. It seems to run fine, but this is my first deisel. I don't see any smoke, white or black, at start up or under load. And the oil level stays at the correct level and smells fine. It does fail to start the first time once in a while. But I still feel it should get better mileage. From reading others here I was chalking it up to "winter blend" what ever that is. How would someone know if they had an injector problem?

I am having the same symtoms as you are other than my pickup has been smoking under load lately. My problems started this fall and early winter. I am actually on a snowmobiling trip now, and pulling the trailer it has good power, but, it has a knocking noise and it gets pretty loud when getting a good load on it. I had trouble getting it started one night, cranked fast for a few times and then I gave up. It has been seeming to start hard, cranks longer than I thought it did last winter, but that was a long time ago. Anyhow the next morning I was gonna put it in the warm shop, and it started right up. After that I unplugged my Quadzilla, and have not plugged it back in yet. My pickup also idles rough, you can really notice it when it idles up to 1000 RPM, it sounds like it is missing almost. I am going in to the dealer when I get home, I have about 68000 miles on the clock.

 

[brods]

Could someone with doubts put the $350 towards buying improved injectors of some sort? Are enough of these things failing to make replacement a reasonable consideration? I sure would like to know where my mileage went, besides down. PBrauer, I would hate to end up chasing my tail like it sounds like you have been having to do. Thanks for your help

If you see no signs of an injector problem, start with the simple things first. When did you first notice the mpg drop? Was it around the time or shortly after the cold weather started? Was it after you modified something or added accessories? Do you drive differently now that the truck is broken in? How many miles do you have and when was the fuel filter changed? Are the tires aired up correctly? Etc.



Fwiw I definitely see a trend of lower mileage in the winter, typically 14-15 mpg. The summer brings the 17 -18 mpg numbers out. My truck mpg average is 15. 5 mpg over 40k miles.