Please advise: 2006 Dmax died on interstate

[ccole]

Hello friends,
Had kind of a unfortunate day with the 2006 Duramax today (8000 miles) . Wondering what you guys think might of happened, that caused my problems. This is how the day went:

Started Dmax this morning, ran fine. Went to local fuel station (where I have always purchased fuel) and filled up w/ diesel. It was about 1/2 tank low. Drove approx 30 miles and "engine light" illuminated on dash and truck went into limp mode. Max RPM allowed was 2000 RPM. Called OnStar and they couldnt diagnose error code. They recommended to shut truck off for 5 minutes and see what happens. Did that, and truck went out of limp mode (ran fine), but engine light still illuminated. I also notice excess black smoke pouring out of exhaust even during slight accleration on interstate, but power and accerlation were fine. Got to town and truck idled very rough. I could feel the motor missing/shaking with a obvious miss while idling (very violent). When truck would come off idle during accleration, I could hear the injectors ticking. Sounded really bad. Shut truck off for approx 6 hours. Started truck back up, ran fine and sounded fine. No "check engine light" illuminated. Got back on interstate to head home and all was going well. Got the exit ramp and slowed down for stop sign. Truck began shaking again during idle and was very rough. Truck then died and that was it. Will not fire at all. Check fuel filter (which has about 2000 miles on it) and it was full and primed. So, I had to have the truck towed 45 miles to the closest dealer. Any ideas?? Thanks in advance for any input!!!

[Duramaster]

I know you said that you put "DIESEL" inthe tank, but do yourself a favor and remove the fuel fill cap and use your nose to sniff for gas. :o You might even remove the fuel filter and dump it out in a clean pan and check for contaminates (and gas).

[ccole]

Hey Duramaster-
Thanks for the reply. While waiting 1 hour for the tow truck to arrive, I did consider gasoline in the tank could be the culprit. I removed the fuel cap and smelled and couldn't smell anything other than diesel. But, like I mentioned before, I only had to put 1/2 or 1/3 tank of fuel in the truck to top it off before we started our trip. So, I cannot be 100% sure that the fuel station had pure diesel in their tanks. It is at the dealer now and see what they discover.

[Dakster]

Please let us know what happens... So if we encounter the same thing we know what to look for/at.

Another reason I really don't like the fact I have a DPF. I bet that would have clogged long before your truck died....

[Buck]

Sounds like you got some water in your fuel and or a plugged fuel filter;)

[ccole]

**update**

Dealer called and said they got it to run, but is engine still has a significant miss and setting several codes. He said they drained some fuel from the filter and it looked "cloudy" and questioning the quality of the fuel. I have never experienced quality of fuel issues with my local fuel station, but this could be a first. My question is, does diesel fuel mixed with water content turn cloudy? Thanks!

[Dakster]

It can. I had a Ford that got water in the fuel and it looked murky/milky when drained into a clear container....

Depends on whether it was separated or emulisfied. This is usually dependant on the type of water separator additive. Emulsion encapsulates the water and is what will make the fuel look cloudy/milky, while a separation agent will split the water away from the fuel - Think oil and water in a jar...

Hope this helps. I would go back to you usual fuel station for two reasons. One to warn them so no one else goes down and the other so that they can pay for your upcoming repair bill.

[Duramaster]

Good job Dakster! I have had so many vehicles come into the shop with water in the fuel! And of course the customer is expecting warranty. We just tell them that GM didn't put the water in the fuel. Now say that to a customer that just bought their truck and it only has 1000 miles on it!!!!! :D

[Duramaster]

Check this out!!!!! I just found this on the GM SI website. Boy am I behind!!! This might be a little exciting for some of you!!! Especially the part about the "AUXILLARY" filter! :D




Subject: Duramax Fuel systems Vacuum Specifications - keywords 6.6L hard LB7 LBZ LLY P0087 P0088 P0093 P1093 presure restriction specification start system #PIP3315B - (02/13/2007)



Models: 2001-2007 Chevrolet Kodiak, Silverado

2001-2007 GMC Sierra, TopKick

Equipped with the LB7, LBZ, or LLY 6.6L Diesel Engines




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This PI was superseded to update part information. Please discard PIP3315A.


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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
A normal fuel system vacuum reading on the 6.6 LB7, LBZ, or LLY engine is less the 5" HG at WOT ( wide open throttle ) in park or neutral.

Normal fuel system vacuum readings may vary depending on fuel filters used.

Recommendation/Instructions:
At this time, there are five GMSPO filters that the dealer may encounter. There is the original short LB7 fuel filter, the original 6.6 LLY fuel filter, (3/4 of an inch longer then the LB7 filter) the "Black Line" short fuel filter, a white step can fuel filter, and a blue step can filter. The step can fuel filter is described in bulletin 04-06-04-070.

A dealer may also find an add-on primary fuel filter kit. General Motors has tested only one type of primary fuel filter kit. The Racor primary fuel filter kit #RK32313 is the only filter kit that GM recognizes as a properly engineered kit. It is made to properly fit on the 6.6 Duramax applications. This fuel filter kit is not available through GMSPO. If a dealer needs sales information, or parts for the Racor primary fuel filter kit # RK32313, use the internet web site Racor.com to locate the closest Racor distributor.

SI Fuel System Vacuum specifications do not change for the 6.6 LB7/LBZ/LLY engines with the original short LB7 fuel filter, the original 6.6 LLY fuel filter, the "Black Line" filter, or the new step can filters.

The vacuum readings on a vehicle with an add-on primary filter kit may be higher due to the extra restriction the add-on primary filter will produce.

Below are vacuum readings expected for the 6.6 LB7 LBZ or LLY engines when an add-on primary filter kit is installed: These readings are with clean fuel and new filters:

[Mitchagain]

I am going to take a stab at this. "Add on Primary" filter means Pre-OEM filter? Or does it also include the Post-OEM filter?

[Duramaster]

I had the parts guy check the availability of it. Not available locally, dealer cost is $267 and yes, it is pre OEM. I want to try and find a way to see it!!! ;)

[ccole]

Update..... The dealership called yesterday (Friday) and said the truck is fixed. They said they replaced #2 & #4 injectors, as well as the fuel filter. So today, we drove to the dealership (1 hour each way) to pick up the truck. I started it up, sounded fine at idle. There was a noticable "injector ticking noise" immediatly when coming off idle. I went ahead and drove the vehicle a couple blocks and attempted to get on interstate....and during mid-acceleration, I seen considerable black smoke exhaust, then the engine started missing/misfiring injectors, then greyish colored smoke. (this all took place in a couple seconds under medium acceleration). I backed off the throttle immediatly and drove back to the dealership. Again, it seemed to sound fine at idle; so I asked the general manager of the dealership to ride with me and witness how the truck would run during acceleration. Luckily enough, it happened again so he would witness the issues. So, I left the truck there to see if they can get it right the 2nd time and I went home empty handed.

The General manager told me they only replaced #2 and #4 injectors, due to they were the only ones acting up at the time of repair and GM is VERY gun-shy of replaceing injectors under warranty. Even if the truck only has 8000 miles. I truly think that all 8 of them should be swapped out, fuel filter changed again, and the fuel tank be drained and re-filled with fresh fuel, just to eliminate all aspects of issue(s). It's so frustrating spending 51K on a truck that now has 8000 miles on it and it wont run. What do you guys think? What kind of action should be done on my part? Thanks in advance for any input.

[Dakster]

At this point, you don't have a choice but to let them fix it. If they drain and fill the thank with fresh fuel it is on your bill, although I agree that it should be done. I would probably do it myself just to make sure I wouldn't kill another set of injectors that GM wouldn't pay for. However, try to keep the drain/refill action off of your bill. Later on down the line you don't want someone questioning "Why was the the fuel tank emptied and filled with fresh fuel? This sounds like contaminated/bad fuel and we don't cover that." I'm not saying to lie about it, but it will create less hassles. It sounds like your dealer is trying to protect you. My dealer did this with my 07 Suburban that they had trouble fixing.

I would test my fuel and oil. I believe it only costs $20/ea and will tell you for sure what is happening with your motor and fuel.

Now, let's say they change the injectors out and it still doesn't run right. I would check your states Lemon Law guidelines to make sure you protect your rights just in case. While the next repair is being done, be sure to read how it is computed to see if it makes sense for you or not. BTW, it is waaaaaaaayyyyyy too early to think about Lemon Law, but it doesn't hurt to know it so you don't give the dealer/gm any more time than you have to. It will also save your health and frustration knowing that no matter what there is a light at the end of the tunnel.

Good luck! I was just in your shoes and I don't wish it on anyone.

[DieselMonk]

obviously that water in fuel alarm didn't work either. Man... that must of been some crapy fuel and that stuff isn't really cheap anymore either.

[ccole]

Well, I got the pickup back today. It took 4 injectors, 2 fuel filters and they also drained all fuel from the tank and replaced with fresh fuel. Sounds like I did get some bad fuel causing all of my problems. (Even though I purchased from the fuel station I have done business with all my life). Obviously, these Dmax's are much more particular about the quality of their fuel compared to my old 6.2 diesel. I am also surpised (and relieved) that the dealership took 100% care of the problem, even though I would consider the fuel station at fault. Regardless, the "water fuel sensor" in the base of the fuel filter never did come on ( I would of thought it would set off a code or something) and I think I will start studying up on a add-on fuel filter kit. Thanks for all the advice! I truly appreciated it.

[Duramaster]

Here is the racor unit approved by GM. :)



www.parker.com/racor/Prodbul/fuel/7605-GMC2500HD.pdf

[DMAX-HD]

They should be replacing the whole bank of injectors not individuals. I had a number 3 go out on on my 03 and the dealer that I took it too said thats the way GM recoomends doing the injector warranty.