<H1>Engineering Is Investigating the 04 6.6L LB7 Injectors for Concerns of DTC P1093 and High Return Line Flow Rates - kw hard no start #PIP3109 - (Aug 19, 2004)</H1>Engineering Is Investigating the 04 6.6L LB7 Injectors for Concerns of DTC P1093 and High Return Line Flow Rates


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The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.<A name=ss1-1546121><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1546121#ss1-1546121" target="_blank">
<H5>Condition/Concern:</A></H5>


04 LB7 6.6 diesel engines with DTC P1093, hard start, or no start. There is an engineering investigation to identify a maximum of TEN 2004 6.6L LB7 engine equipped vehicles built after 08/2003 with the concern of DTC P1093, hard start, or no start. The investigation is to find injectors with high return flow rates and ball seat erosion.<A name=ss2-1546121><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1546121#ss2-1546121" target="_blank">
<H5>Recommendation/Instructions:</A></H5>

<LI =1>Complete the normal SI diagnostic steps that consist of properly determining if the vehicle requires injector replacement because of a high return flow rates.
<LI =1>If Fuel System Diagnosis High pressure Side has led to injectors with a high return flow rate, and the vehicle had the conditions of P1093, hard start, or no start, please contact DMAX Senior Service Engineer Michael Rumschlag at (734) xxx-xxxx. If Mike Rumschlag is not available please leave a message with your phone number. If you do not receive a return call after one hour continue on with the injector ordering and repair process. </LI>


Some background, "Ball Seat Erosion" is thought to be an "event based" failure i.e. the fuel is contaminated or contaminated fuel is pumped into the tank. Product improvements were implemented at the start of 2004 to address "cracked injector body" and "high pressure seal leak". This is why the investigation now is focused on 2004 6.6L LB7 engines with high fuel return rates.


NOTE : Vehicles exhibiting oil dilution (fuel in oil) are excluded. Ball seat erosion is related to excessive amounts of a silica base (sand) 1- 4 microns/hard particles in the fuel. Vehicles most likely to exhibit the subject failure would be those operated in farm/off-road conditions or be suspect of using fuel containing excessive amounts of silica base ( Sand) 1- 4 microns/hard particles for any other reason. Qualify vehicle with codes/concerns/conditions above. To help identify Ball Seat Erosion as the likely cause of the issue, utilize SI document "fuel system diagnostics high pressure side". If ball seat erosion is the cause it will identify 1 or 2 injectors at the first fuel pressure point, with the first injectors replaced/lines capped additional injectors will fail at a second (higher) pressure point. With the ( Sand) 1- 4 microns.


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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.<A name=ss3-1546121><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1546121#ss3-1546121" target="_blank">
<H5>Models:</A></H5>


(2004 Chevrolet Silverado and GMC Sierra, 2004 Chevrolet Kodiak and GMC Topkick C4500/C5500 Series with 6.6L Duramax™ Diesel Engine (VIN 1 -- RPO LB7)


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Sounds like Silver Lake sand dunes isn't a good place to run a Duramax! Glad I only do it once a year. Why are they looking at 2004 LB7 engines? Is there any real difference between a 2003 LB7 and a 2004 LB7?

Seems like they fail to address the fact that THEIR OEM fuel filter cannot clean fuel suffciently to avoid ball seat erosion. If they know silica in the 1-4 micron range will damage injectors, why didn't they redesign the fuel filter to acomplish this, they have had a couple of years now...nah, lets blame it on the customer...http://www.dieselplace.com/forum/smileys/smiley18.gif

Sounds like they are still looking for the 10 vehicles.


Also sounds like they are trying to blame the fuel (void warrenty?). Why not just install a 1 micron filter???(where have we heard that before)?


Which injectors are at the "first fuel pressure point"?

So let me get this straight. If you put on a secondary fuel filter, they might void your warranty. If you don't, and you get some bad fuel, they will deny warranty because of the fuel. Sounds like catch 22 to me.http://www.dieselplace.com/forum/smileys/smiley7.gif I guess just risking the warranty with the extra filters is the best bet, huh? At least I know I have done what I can for the injectors to avoid the silica problem.http://www.dieselplace.com/forum/smileys/smiley32.gif Where are those folks that said it was a waste of time and that said time will tell? Looks like the old man is starting to squak a little. Or the ones that said the OEM alone was just fine. Maybe GM isn't all knowing like George.http://www.dieselplace.com/forum/smileys/hihi.gif

So let me get this straight. If you put on a secondary fuel filter, they might void your warranty. If you don't, and you get some bad fuel, they will deny warranty because of the fuel. Sounds like catch 22 to me.http://www.dieselplace.com/forum/smileys/smiley7.gif I guess just risking the warranty with the extra filters is the best bet, huh? At least I know I have done what I can for the injectors to avoid the silica problem.http://www.dieselplace.com/forum/smileys/smiley32.gif Where are those folks that said it was a waste of time and that said time will tell? Looks like the old man is starting to squak a little. Or the ones that said the OEM alone was just fine. Maybe GM isn't all knowing like George.http://www.dieselplace.com/forum/smileys/hihi.gif


I also have to agree that secondary filtration is money well spent as it applies to these new HP injection systems. I also believe preventing free air via the lift pump as Dodge uses and GM decided to delete is also a plus. Here's a link that targets injector cavitation at the SAME area in the injector. Recir/Return side. http://www.fluent.com/solutions/automotive/ex200.pdf (http://www.fluent.com/solutions/automotive/ex200.pdf)


Oh I almost forgot, Thanks Eric http://www.dieselplace.com/forum/smileys/smiley1.gif

How would that go in a court room? You say I had sand in my fuel and I say you have a poor design that causes cavitation. Did you catch that part about diesel vapor? Boy, that discussion sounds familiar, huh a bear?http://www.dieselplace.com/forum/smileys/hihi.gif

very interesting eric.. i presume the 04lb7 injectors are different
(older) than the current revision being installed as replacements for
01's and 02's?

http://www.dieselplace.com/forum/smileys/smiley3.gif Ruh Ro Raggy......I hope mine holds together......I am not saying they can't, but I don't see how they could void anyones warranty over dirty fuel. It is not the customer's fault. It is the fault of the fuel company and GM for thier http://www.dieselplace.com/forum/smileys/smiley35.gif fuel filter.


I guess if a thief can hurt himself in someone's house that he is trying to rob, then sue the owners, anything is possible.Edited by: dmaxfan

They can say the fuel is your fault and tried to with George. He won his battle, but it just goes to show you.

I wonder how long it will take before they will warranty all the injectors no matter what year your vehicle is?.....

I wonder how long it will take before they will warranty all the injectors no matter what year your vehicle is?.....

Those of us with 03's & 04 LB7's can only hope!

Product improvements were implemented at the start of 2004 to address "cracked injector body" and "high pressure seal leak".


Looks like even 2003 models are not safe from the "cracked injector body" failure mode. Interesting. You 2003 owners take notice of the above after your 5yr/100K mile warranty expires (looks like a reason to extend the 7yr/200k mile injector warranty of the 2001-2002 model to 2003 models).Edited by: OC_DMAX

Ball seat erosion is related to excessive amounts of a silica base (sand) 1- 4 microns/hard particles in the fuel. Vehicles most likely to exhibit the subject failure would be those operated in farm/off-road conditions or be suspect of using fuel containing excessive amounts of silica base ( Sand) 1- 4 microns/hard particles for any other reason.


Once again, the need for additional fuel filtration is identified. Those that have been involved in the fuel filter testing over the last several years already know thishttp://www.dieselplace.com/forum/smileys/smiley2.gif, those that have not or are new owners of a DMAX take notice.

Ive been going back and forth on whehter or not i want to go secondary filter...i mean i understand the benefits, but i dont know just seems like one more thing to worry about...but now i read that d-maxs in farming conditions are more prone...oh good thats me..maybe ill go over to erics site...


anyways since its obvious that the gm filter is not up to par, is there a filter thats available that has a smaller filteration # and would screw right on to the stock filter base?? or is that just a dumb ? and way to easy of a soultion?

It sparked my interest when I read that, especially what you guys already hit on, the damage is from particles in the 1-4 micron range and yet, common consensus is the filter is good to about 6 microns... Hmm


I suspect that they point to the 04's because they would be built with the latest and greatest injector design and they likely want to see how/what/if they are failing.


I took apart an LLY injector today and I must say.. It is suprising how small the "ball and seat" really are. I dont think I can get my 6.1 MP camera to get a picture of the ball. If its 1/32 in diameter, I would be suprised. I will see what I have for pics...

I wonder how long it will take before they will warranty all the injectors no matter what year your vehicle is?.....

Those of us with 03's &amp; 04 LB7's can only hope!






Well it will give us something to look forward to at least... I think eventually they will do it, or they will have to as they start to fail, if they do. People will expect it as they have done this for the other model year trucks.

Funny



As adults we take the blame for our actions (unlike children)



GM is acting more like a child then a major corp.



They dont/wont/cant take the blame for fuel having dirt in it and
getting passed their crappy filter to the highly sensitive injectors.



1-4 microns????



I know of NO filter that will filter below 1 micron.

I know of NO filter that will filter below 1 micron.


I'm not sure I know of a fuel filter that will filter below 2 microns. And to do that with high efficiency probably will take two in series. So, guess we are kinda stuck.

JimEdited by: jholly

If you look at the test data that several have done, you do get a substantial improvement with one extra filter. I know that I added a lift pump and put one before that in addition to the mega post OEM. In total, I have 3, a 30 micron, a 5 micron and a 1 micron. Without putting a second mega (which I have NO idea where to put thathttp://www.dieselplace.com/forum/smileys/smiley5.gif) I don't see any way to do more. I guess I could change my 30 down to a 10 and change it twice as often. Or just add a Nicktane post lift and have 4.http://www.dieselplace.com/forum/smileys/hihi.gif Edited by: chuntag95

Or just add a Nicktane post lift and have 4.http://www.dieselplace.com/forum/smileys/hihi.gif


And you'd have the added avantage of increased fuel capacity in the filters and hoses!http://www.dieselplace.com/forum/smileys/smiley2.gif

http://www.dieselplace.com/forum/smileys/smiley32.gifhttp://www.dieselplace.com/forum/smileys/hihi.gifhttp://www.dieselplace.com/forum/smileys/smiley36.gif I missed that added capacity benifit. I guess I could mark off the replacement tank then.http://www.dieselplace.com/forum/smileys/smiley2.gif

We could hollow out our tanks and fill it up with filter media.

How does driving in farm/offroad conditions make fuel suseptable to 1-4
microns silica? Fuel comes out of a filling station tank and goes into
the trucks fuel tank. The fuel may have come from jabip. I would
understand if they were talking oil and aircleaner.

Poorly maintained on-site farm fuel tanks, I suspect.

How so you get silica in a poorly maintained tank?



The whole thing sounds stupid. Almost like they are coming up with a
poor excuse to void warranty. The injection system designed properly
should perform for a lifetime with the installed fuel filtration
system, designed to protect it from work induced dirt.



Enough said


Edited by: hoot

Oc is prolly right w/regards to the construction/farm "enhancing" the problem...However, and i cant speak for all other farmers or anything but our road fuel goes through just as fast as the red fuel....And weve got a filter on the pump(im sure prolly all stations got one) taht we try to keep on a regilous changing schedule...I dont however know what the filtration is...

I just wish everybody would stop making excuses for GM

My trucks have run fine and have out performed any previous and current brands i have owned including the mighty cummins.So no excuses needed from my little fleet of Durahard chargers!Get a grip boys!Some are going to fail due to stats and that is all .

How would you know Broker? Your unsubstantiated speil is getting old.

My truck had the Nicktane installed at 5K. The injectors failed at 15 K. The dealer is replacing all 8 of the injectors. I have had a rental loaner truck for 3 weeks.





Jess

How so you get silica in a poorly maintained tank?



For every x amount of fuel that is pumped out of a tank, whether in your truck's fuel tank or a storage tank, x amount of air replaces it, no matter how dusty (ie silica) that air is. Over time, it adds up. That's why some companys sell tank breathers. And like George at Avlube (http://store.avlube.com/atctonmodd2.html) says, "Diesel fuel is like a magnet for both dirt and water!".

Now I wonder how many service stations have tank breather filters & how often, if ever, they clean their storage tanks. And no, that doesn't excuse a manufacturer for having a sub-par fuel filter system.

For every x amount of fuel that is pumped out of a tank, whether in your truck's fuel tank or a storage tank, x amount of air replaces it, no matter how dusty (ie silica) that air is.


So where does our tank vent?


Is there a breather filter?


What is the efficiency of the filter?


Sounds like there could be a really cheap fix.

It's probably the cap. I thought I'd seen somewhere that the cap should be replaced if used in a dirty area for X amount of time.http://www.dieselplace.com/forum/smileys/smiley5.gif





Burner------------------&gt; http://www.dieselplace.com/forum/smileys/smiley4.gif

I can see it now..... who makes the best tank breather filter.. Uni? http://www.dieselplace.com/forum/smileys/smiley36.gif

I can see it now..... who makes the best tank breather filter.. Uni? http://www.dieselplace.com/forum/smileys/smiley36.gif


Well, actually it's AVLube. But it's designed for bulk tanks, so it's huge, pricey and requires dessicant replacement to maintain humidity control - main reason that it's not used on-vehicle and not widely used in distribution.

It's probably the cap.


I think that's why your fuel cap "ratchets" or clicks, so you don't overtighten it. I also remember something about some gas engine vehicles setting off their SES light when the fuel cap wasn't properly tightened. Don't know if that applies to the Duramax. http://www.dieselplace.com/forum/smileys/smiley5.gif

My theory on the source of silica contamination is from the bulk truck transfer hoses and the dirty/oily looking nozzle you grab off the pump and stick into your filler neck.


But GMs policy appears to be going the way of, "You use this truck on the farm? Well, then, no warranty work for you!"http://dieselplace.com/forum/smileys/smiley13.gif

It's probably the cap.





I think that's why your fuel cap "ratchets" or clicks, so you don't overtighten it. I also remember something about some gas engine vehicles setting off their SES light when the fuel cap wasn't properly tightened. Don't know if that applies to the Duramax. http://www.dieselplace.com/forum/smileys/smiley5.gif




that actually happened to a ford exploder we owned once....

My buddy that runs hot shot service just turned over 200K on his 2002 Dmax. Strange thing is he is completely stock. No aftermarker filters, Nothing. The wife said he called the other day and needs me to call back ASAP. Well, I said to myself, this is it. The bad news awaits. As I called him back and prepared myself for the worst news possible he asked me where I purchased my tires because he was ready for another set. http://www.dieselplace.com/forum/smileys/smiley3.gif I laughed a little to myself and told him to stay in touch.

I think luck is also a factor in all of this. I have all the extra filter and pump stuff and hope the luck will show up too!

I think this is a larger issued than GM says. I dont beleave all injector failures are broken housings or corroded electronick in the injector. I have always felt fuel is the sorce.Not all but some.There are so many things that can break down a high psi injection system.
Pressures are getting higher to atomitse(sp) the fuel to burn more efficient. Lower emissions. yet the fuel refiners are not doing anything aboove and beyond to match that.the fuel we get is and has been the same for years.as the demand for diesel rises we see the priced coming up.I remember when diesel was 30-50 cents cheeper.
now its fliped -flopped..

When I was in New Mexico we had engenering looking into a small case of dealers in our area having bad fuel sending units. This was found to be sorced at the fuel and having to much sulfer in it. The GM fix was take sending unit out clean the unit with brake cleaner.
reinstall.
After removing a dozen or so I found the same findings,along with excessinve amounts of sand.
Nwe Mexico has very fine sand.I have seen that here in Oregon as well. I have removed a few sending units here and have seen sand as well.

Fuel is junk........
I would advise to ask the station owners if they filter the fuel and how often they change the filters.

worse case get 4 10 gallon fuel tanks and filter your own fuel. coffee filters work good.

2nd filtration will not hurt.

I'm too lazy to get 4 10 gallon cans and pre filter. That's why I added the pre lift pump 30 micron filter and the post OEM 1 micron Mega.

My truck had the Nicktane installed at 5K. The injectors failed at 15 K. The dealer is replacing all 8 of the injectors. I have had a rental loaner truck for 3 weeks.





Jess





Jess ~ Cudya provide insight as to nature of phailure? Ball/seat erosion? Cracked body? I ask as I too had the Nicktane instl'ed at approx 5Kmiles and coming up on 15K soon. I wud think the cracked body failure mode wud have nothing to do w/philtration tho ~

Maybe some areas (refineries) have poor fuel standards. No
"quality control" Its a shot in the dark right now. http://www.dieselplace.com/forum/smileys/smiley13.gif

I can see it now..... who makes the best tank breather filter.. Uni? http://www.dieselplace.com/forum/smileys/smiley36.gif


Ya buddy my vote on the UNI A quality product

Uh huh.

The next step will be GM installing "Duramax Certified Fueling Stations" across the country ... $4.99/gallon and unless you use the GM fuel it will void your warranty. I would like to see the ratio of "farm" trucks with injector failures compared to non-farm trucks. It sounds like GM is coming up with yet another excuse for a poorly designed fuel system that can be used to blame the customer. This injector thing is WAY beyond pathetic on how GM is dealing with it. So far I've seen the extended warranty on 01-02 trucks ...and now this with the 04's ... guess the 03's must be fine.http://www.dieselplace.com/forum/smileys/smiley5.gif

Hate to do this but here I go again! For those of you who may not recall my plight, I had hard start/no start problem at 30,000 miles and after much convincing got a new set of injectors. Shortly thereafter I install a Cat filter pre OEM. Well here I am at 75,000 with the same hard start/ no start problem. Stopped at dealer who said injectors are on "super galactic backorder" and must be ordered with VIN for truck they will be going in. Told dealer to call me when injectors come in, meanwhile I leave truck running all day at $2.25/gal!! Truck usually starts in the morning, only had to use ether once so far. Tech also couldn't command max rail pressure so there might be a pump problem too. Hope injector replacement doesn't become an annual thing!!

Gadzooks Doc! Second set?!?!?

i dont think ether is good fer newer pickups...seems like i remember a story not to far back about tearin a d-max apart and the insides was all beat up...

Hook up a reverse osmosis filter that constantly filters the fuel in the tank or get an old dialysis machine...http://www.dieselplace.com/forum/smileys/smiley5.gif

Dr Crane, We have injectors. They are becoming much easier to get ahold of now


I dont doubt your second set is bad... I have had some trucks with 20+ injectors through them....so far.http://www.dieselplace.com/forum/smileys/smiley18.gif

http://gmdieseltech.com/inj1.jpg


Above is link to gutted pic of injector, the pen tip is pointing to the "ball" and the part just to the left of it is the "seat" we hear so much about. I have an LLY injector I am tearing apart to, will get more pics up soon


Now you can see how small of a piece we are dealing with with the ball and seat erosion issues.. It dont take much


Edited by: dmaxalliTech

Great Pic, Almost makes you wonder how they last as long as they do. http://www.dieselplace.com/forum/smileys/smiley5.gif

That is quite a wee piece for such a mighty engine.

Eric, thanks for the pic!! http://www.dieselplace.com/forum/smileys/smiley32.gif

Any chance of a cutaway illustration, or schematic? If you know about a link to a site, for a Bosch injector?

I dont doubt your second set is bad... I have had some trucks with 20+ injectors through them....so far.http://www.dieselplace.com/forum/smileys/smiley18.gif





Dmaxali, your startin to scare me man.......were these high milage trucks, bad fuel or just unknown cause....did they have extra filtration?

less then 100k on truck, I think that the first few were becuase of very early injectors... I put in 3 of them after that when I first hooked up with the owner, they were knocking, then policy come out and he had some smoke, put all 8 in now


We added a Racor filter to it mounted Pre. Also used a filter mag from www.kennedydiesel.com (http://www.kennedydiesel.com) and change both Pre and OEM every 10k.. He is nervous as you can imagine after that many injectors.

Here is, as they say, the rest of the story.


My truck has been down for about 7 weeks now. If you include all of the time it was hard starting. Then it finally died about 2 weeks ago and had to be flatbedded back home. Sat at the dealr for 2 weeks waiting on injectors. Then they got them in. Got a call Wednesday this week saying it was done. Drove the loaner back, got the keys and started the truck. Started right away, and also started knocking and smoking right away. They say they test drove it. I am not sure how. Smoke was pooring out of the dip stick tube and crankcase breather. Needless to say, I left the truck and took the loaner back. They called later and said that 3 of the new injectors tested bad. Now I don't know how much longer I will have to wait again.


Jess

http://www.dieselplace.com/forum/smileys/smiley7.gif


Now what I want to understand is how jesshd installed a nicktane filter kit at 5k miles, and at 15k all 8 injectors went bad??? I don't understand that one?, something does not make sense here. This engine &amp; manufacturer is the only one of it's kind to tell everyone that there are special guidlines to the functionality and daily use of the mighty duramax, if something goes bad, here's a 1-800 number for unconditional support http://www.dieselplace.com/forum/smileys/smiley18.gif.


It's either that or we like being crash test dummies.......http://www.dieselplace.com/forum/smileys/smiley5.gif

I am not sure that all 8 went bad. The new service policy is that they will replace all 8 at once. I had a high return rate on the drivers side. They say that some or one of the injectors had a cracked body. Now with the new injectors, 3 are bad. I am not sour on the truck, I love my truck. I am sick of this bull$sh*t with the injectors and the BS with the dealers blaming a factory defect to cover up a factory problem.


JessEdited by: jesshd

Jess, Sorry to hear about your troubles. The cracked bodies would not indicate poor filtration so fuel quality can't be blamed here. Looks like another negative for the design itself. Good luck !

I highly doubt that the new injectors are bad, especially three of them.... Sounds like to me an assembly error or something like that.

That is what they said. I don't think they have pulled it down. All he told me was that 3 of the injectors "tested bad". What else could cause the knocking and smoking? They were supposed to put in all 8 new and that is what they said they did. The SM is out sick, so I yave been dealing with another SW.


Deezul