Okay, the injector failure survey results are tabulated. I just included year, mileage, and whether or not you reported problems. I realized about halfway in I should have kept track of lly 04s vs lb7 04s, but I didn't and wasn't going to go back. Sue me. Anyhow, if anybody wants the raw excel file, pm me with your email and I will send it to you. Here is a jist of the results:

501 total reports (doesn't include multiple failures or those who didn't provide complete information). Of those 501, there were 175 failures (34.9%). The yearly breakdown was:

Year Total Bad (%)
2001 99 46 (46.5)
2002 152 51 (33.6)
2003 161 60 (37.3)
2004* 89 18 (20.2)
*includes one 2005 (with no injector problems)

Average mileage failure doesn't really say much since the standard deviation was so huge, but the total average was 53324 miles, with 71507, 63897, 41555, 16126 for 2001, 02, 03, and 04 respectively.

I compared the % of total trucks by year vs % of total injector problems, and unsurprisingly 2001, while accounting for just under 20% of the trucks, accounted for 26% of the failures. A little more surprising was that 2003 accounted for 32% of the trucks, but accounted for 34% of the failures.

Of course all this is from a limited data set and there are a million more variables than simply the year it was produced-so take all results with a grain of salt. I won't be back in front of the computer until tomorrow, so any requests for the excel file will be filled then.

Thanks for doing this.

If you can, keep it going. It's good for all of us. Many will say how flawed this is. Truth be told, there is some significance to it. I would personally take it for granted that injector failure within the first 100,000 miles is a given. Consider yourself lucky and waiting for it if you haven't had it.

Is it a big deal? I think it's horrendous.

Hoot,

Through your vast network do you have any information on the failure rate, if any, for the Cummins common rail injectors? Since the two engines use very similar Bosch designs, it would be interesting to compare reliability data, even rule of thumb information such Habenero has compiled. If the rates are distinctly different, it would be interesting to know why.

TC

Thanks for doing this.

If you can, keep it going. It's good for all of us. Many will say how flawed this is. Truth be told, there is some significance to it. I would personally take it for granted that injector failure within the first 100,000 miles is a given. Consider yourself lucky and waiting for it if you haven't had it.

Is it a big deal? I think it's horrendous.

Hoot, you are still trying to justify your reason to switch to cummins. :blahblah:

The survey is flawed. Fact.

501 reports is less than 5% of the membership of the diesel place. :damnit1:

The survey would be more accurate if all members replied.

Also, members are more likely to reply to this type of "voluntary" survey if they have problems or have been "scared" into worrying (the Hoot syndrome). Plus, people are drawn to boards like this one when they have a problem, thereby exagerating the ratio or problems to no problems.

My take on the subject.

Yes I do think injectors are/will be a "maintenance" item. But on the same intervals as long life/wear items like water pumps, alternators, transmissions, etc. GM will cover the injectors up to 200,000 miles on the 01 and 02, and case by case on the 03 up trucks.

Yes, some people have trouble before 100k miles. But 35% is just not plausible in the real world. A recall would happen or be forced well before that percentage is reached.

P.S. Dodge and Ford will have the same problem in up coming years as they switch (Dodge already has) to the same or similar Bosch injectors we have (for emmissions reasons).

FWIW, since the 100,000 number was brought up, I looked at the results and of the 175 failures reported, only 12 were over 100,000 with 163 before 100,000.

And yes, I agree, this survey is certainly flawed. That is the trouble with statistics, you can make them look any way you want. I hope anybody looking at these numbers will be cognizant of the fact that it is a very limited data set and can't necessarily be extrapolated out to represent the engine as a whole. But, since the numbers were already there, I just put them together to give people an idea of what they add up to. Take it as food for thought and nothing more.

FWIW, since the 100,000 number was brought up, I looked at the results and of the 175 failures reported, only 12 were over 100,000 with 163 before 100,000.

And yes, I agree, this survey is certainly flawed. That is the trouble with statistics, you can make them look any way you want. I hope anybody looking at these numbers will be cognizant of the fact that it is a very limited data set and can't necessarily be extrapolated out to represent the engine as a whole. But, since the numbers were already there, I just put them together to give people an idea of what they add up to. Take it as food for thought and nothing more.


Habenero, it is great people like you take the time and have the energy to things like this. We all appreciate it. :ro) I was mainly replying to Hoot who seems to have taken the numbers as "gospel" and he will certainly use it to justify his switch. The point I am making to all members, new and seasoned, is that the high number of failures on this survey does not necessarily translate into to "real world" numbers and should not start a mass panic or hysteria.

Food for thought on the 100K mile mark. Probably 75% of the members have less than 100k on their trucks, so this survey will show more failures under 100k miles.

No I have not in any way taken the numbers as gospel. I am not against GM or the Dmax. I am against spending money and breaking down. I don't have to justify anything. I do feel that after personally watching what it takes to replace headgaskets and injectors, it sure is an uncomfortable feeling not knowing if the technician did all the right things. The dirt issue during replacement is real. The injector lines become massively corroded where the nipple connects to the injectors. Crap will fall into the new injectors if extreme car isn't taken and we know there is a huge difference in the definition of extreme care.

Anybody here want an untouched engine for it's advertised life? These stats are not good no matter how you look at it... I don't care who you are you can sit there and justify how great it is because GM is warrantying it... What is so great about that?

My Dodge.... I am not saying it the greatest and i could lose an injector on my way to Indy tonight. How the heck do i know. Hopefully the differences in the Cummins design, which btw is fairly significant, will be more robust. Judging from postings on TDR it really doesn't look to be a major problem. Again... no decent survey for Cummins but you simply don't see very many postings on problems in general, truck too.

You guys stop piling icing on the cake..... open your eyes and stop saying it's ok.... its not ok unless GM pays for the whole bill including lost wages and whatever.

They are very nice trucks. GM had the chance to really do it this time but low and behold.. another major diesel gremlin.

That is the only justification I have for switching. The rest is just for fun and change. The Dodge is a cruder truck.. not quite as cushy. That's ok with me.

My '01 DMAX is purring along like a Kitten at 50K. No injector issues at all, but I credit a lot of that to the Nicktane I installed early on. I feel it is fuel quality related mainly and perhaps some injector quality control issues during manufacturing.

Regardless, I am getting approx 18+/- mileage and very happy. Towing I see 12 -13 MPG about 9K loaded trailer weight. Never a problem to date on any trip I have taken. Some minor fixes at the dealer, battery, NSMU switch and the biggest item was the famous Fuel pressure regulater control valve or whatever the heck it's called. Surge was noticable.

Anyway, my son just bought (December) a '04 Dodge diesel with the whole package. He started out getting 10 MPG and 5 months later it has climbed to 11 MPG. Dodge guys all say mileage gets better when the truck gets broken in. He has 9K on it already. I seem to recall (in a galaxy far far away) when I first got my new '01 DMAX I was getting 18 on the first tank and I am still getting 18 (high once was 19 and low was 17.5) so what are the other Dodge guys geting? Hoot--- truth be told, what are you getting from day one and how much has it improved? Tell the truth now please, there seems to be lots of new Dodge guys getting less than 15 MPG at best never mind towing mileage. What's the deal with that? Why does the Cummings have to get broken in and the DMAX is ready right out of the new box?

All the best regardless of what you drive.

...Why does the Cummings have to get broken in and the DMAX is ready right out of the new box?

All the best regardless of what you drive.

There is no G in Cummins! There never has been, there never will be. Why is it so hard for people to get right??? (Sorry, pet peeve of mine, not intended to be personal)

My 03 Max didn't get its best mileage right off the lot. It started out around 16 on the interstate, but climbed up to 18 by about 10,000 miles. I have heard others say the same as well. I think most engines (particularly diesels, but not exclusively) don't get their best mileage right off the bat. The internal parts have to wear-in to each other, and with that initial wear comes added friction. Added friction robs a little horsepower, and with it a little fuel mileage.

If the injector going bad is a shoe in by 100K as Hoot pointed out, shouldn't Mtomac had a problem? He was over 100K when he elected to go with bigger injectors, not because they were bad. And he has been a tuff on his truck as anyone could be.

Habanero, another big thanks for taking the time to do this. It is appreciated very much. You :ro)

X2