Thank you for your excellent post. 3 months ago I was getting fuel in my 2003 Chev. 2500 Duramax truck and I left the fuel tank open and proceeded to the automatic carwash. Water and liquid from car wash got in my fuel tank. I put the recommended amount of SeaFoam in the fuel system on two different tankfuls and have been running Lucas fuel treatment every other tankful after the incident. Today I am attempting for the first time to replace all fuel injectors. I am replacing them because the truck was smoking and two dealerships did a balance test and said they were bad. While removing fuel supply lines today, I found a lot of rust and a couple lines had a yellowish green liquid in them on the injector nut side. I checked the dip stick. The oil looks good. I plan on changing out the supply fuel lines also. Is there anything else I need to do to ensure that I have fully corrected the problem? I welcome any helpful suggestions.

 

I posted previously as a newby. My 2003 Duramax has 295,000 miles on it but I have taken very good care of it. Although I have been "Chevy Loyal" for a long time, I'm beginning to think it's time to look elsewhere. This truck had bad injectors @ 150,000; GM replaced them. I then re-replaced them at about 225,000 at a cost of $4250 with Bosch injectors, which was 75K miles afterward. Today, I took my truck back to the shop that did the 225K repair, showed him the smoke coming out at idle, and the occasional "loping idle" and he says I need injectors again (295,000 now). Why does this continue every 75K miles after the initiial 150K on the OEM injectors? The only thing I've done is add a PPE Tuner and it's set at the lowest level. I also use an industrial (not retail) diesel fuel additive that "does not" contain any alcohol. ANY Advice?

 

Blake,
I bought my 2002 new. Drove it off the lot 11.5 years and 301,000 miles ago. My injectors go out about every 80,000 miles and have been replaced 4 times so far. Twice under warranty and twice by me.

I do the work myself now that it's out of warranty. It's really not a bad job for a DIYer. I've kept this truck and am still keeping it because the alternatives are not all that much better from what I've seen. In the used department you could buy a Ford with the 6.0 and it's long, long list of problems. Or you could buy a Dodge/Cummins and have the truck fall apart around a pretty good motor. Maybe the Fords with the 6.4 are better? Not when it costs $7,000 to $9,000 to replace a blown fuel pump (recent quote posted on another forum).

In the "new" department you're looking upwards of $50,000 for a truck from any of the big 3 and it even comes with all the EPA mandated CRAP, including the "potato in the tailpipe", poor fuel mileage, EGR valves, DPF fluid, catalytic converters and all the other wonderful things all that crap does to make repairs even more common and expensive. No thanks!!!

As far as injectors go, your tune probably has nothing to do with your injector failures. From all I've read, it's a problem with tiny, tiny pieces of trash in the fuel. At 28,000 psi, it's a bit like sand blasting going on inside the injectors with any particles in your fuel. My truck was bone stock until this weekend when I converted over to a Donaldson filter/ separator that supposedly is much better than the Delco filters I've used since the truck was new. Everything I've read says that dirty fuel is where the problem comes from. Unfortunately, nothing I've read proves that better filtration actually makes the injectors last longer either. But, I will find out if it helps. Being the original owner, I know intimately the history associated with injectors on my truck and they are pretty predictable at around 80k miles. If I get more out of this set (that I changed last month), then I'll pretty much have to attribute it to the filter change.

For your current injector problem I would suggest that you may want to try replacing them yourself. It's a heck of a lot cheaper and it's really not that bad a job. I've done mine twice. It cost me right at $1600 ($201.75/injector) for Bosch injectors from a GM dealer that sells online. I spent a few more dollars on gaskets and bolts but way less than $100. One thing I did this time that I really, really wish I had done last time is that I replaced the valve cover bolts. The factory valve cover bolts are socket-head (you have to use an Allen wrench to remove them). The Allen wrenches or sockets are too long to get into some of the tight spots near the firewall and it greatly increases the time and difficulty of the job dealing with that. Also, over time, the holes in the socket-head bolts also fill with dirt and gunk making it even more difficult. You can't get the Allen wrench down into the hole of the socket-head bolt w/o using hammer to drive the wrench in. It's so tight in some places (working space)that hammering on the Allen wrench is next to impossible. Like I said, makes it a lot harder than it should be. I replaced all my factory valve cover bolts with normal hex-head type bolts this time. It cost me $21 for 50 bolts and 50 flat washers. The new bolts have a 10 mm hex head. I use a Snap On, 1/4" drive, wiggler socket with them and it eliminates all the space problems you get using an Allen socket. Just putting it back together with the new bolts, I know I eliminated several hours worth of screwing with those socket-head bolts!!!

The other thing I did this time that I wish I had done the first time was adjusting the valve lash. Over the years my truck has become pretty dang loud. After adjusting the valve lash, it's back to a quiet as it was when new. My lash was out pretty bad is some cases but it was out by at least 5-8 thousands in every case. Some were 10-15 out. Like I said, made a HUGE difference and it didn't require much to do it. I removed the upper half of the radiator fan shroud and bought a 36 mm, 12 point socket at Advance Auto for about $12. You need the socket to turn the crank using the harmonic balancer bolt. Took maybe an hour and a half extra. You'll also need a feeler gauge if you don't already have one.

Anyway, I did the math and spending $1600 to replace the injectors every 80k miles works out to about 2 cents per mile. I can live with that over paying $50k+ for a new one!! (I don't buy used).

 

Back In Black:

Thanks for your reply, and it was very helpful. I will look into the DIY but since I'm not a mechanic, I'll have to call on a friend to help; but, yes it's do-able.

On another note along this line, we need to find out if the used injectors are clogged with varnish. I'm in the oil business (lubricant sales) and we see varnish problems in Group II refined base oils. I'm told that today's refined diesel fuels go thru the same process, and in effect, the solvency of the fuels are removed as a result of them now being low sulfur diesel fuels. If we put some sulfur back into the fuel, our injectors problems may go away. How do we do that? We find a product like maybe 2 cycle engine oil that still uses Group I refined base oils that have a higher sulfur content and use it as a fuel additive. I'm not sure if their are any legal ramifications with this idea, but I'm not advertising it; I just don't want to pay out $$$ that is un-called for. Just a thought to mull over.

Blake

 

I've read a good bit about the ULSD possibly causing problems with lost lubrication due to the absence of sulfur. What I can tell you is this. My first 2 sets of injectors failed before the advent of ULSD. And they failed at about the same mileage I still getting out of each set on ULSD.

 

Well this past week i received a great surprise... Fuel in my crankcase! Today i began taking apart my top end for a injector replacement. I have noticed a little bit of smoke at idle but nothing too worrying. The diluted oil though i cannot ignore. A 1600 injector replacement is much better than a destroyed engine. One issue i ran into though was the fuel line QDs. I bought a set of tools from Autozone but they dont seem to be working. Any recommendations?

 

quick disconnects: I had a set of the plastic type tools that I purchased first time I did this job. It was a royal bitch to get them lose first time. This last time I spent at least an hour trying to get them lose with those plastic tools and lost patience with it. Took a trip to AutoZone and bought a new set that were made from anodized aluminum. Actually had to buy 2 sets as they split up the sizes just right Anyway, the ones I bought are metal, have a handle built-in and split open along the handle too. The 2 sets cost around $50 combined but were worth every penny. Using these, I had the QDs off in a matter of seconds.

 

thanks for the info gonna try an get to mine this weekend work permitting hope they come out easy needs to be done smokes really bad not to mention fuel getting in the oil pan cant ever be good

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talked to a mechanic where i purchased my injectors. he was telling me racor makes a 2 stage fuel filter. which he says is one of the better ones out there

 

see here:

Racor | PFF50216 | PFF50216 Coalescer Fuel Filter

and from the Duramax Forum:

"Some more info directly from Racor on the new coalescer fuel filter. Its not worth saving a few bucks to get the older style paper element filters, heres why......

Heres the difference:

The PFF50216 meets the current new GM Duramax fuel filtration requirements. These requirements included longer life and better water removal under adverse conditions.

The PFF5544 (old paper style fuel filters) do not meet the new requirements anymore; not because something has changed in the world, only that GM has decided to improve the performance to protect the engine better.

A coalescer filter is a far more sophisticated system than the older PFF5544. Water removal efficiency under harsh conditions (biodiesel and poor fuel) is maintained far longer using a depth coalescer.

Contaminant life testing using real raw diesel fuel here at Racor shows that the filter can hold twice the contaminants. The reason for this is that contaminants are trapped throughout several layers of media, not just on the surface as with a simple pleated filter.

This filter represents GM's final stage of their development of the best possible protection for the Duramax Engine.

It costs more because its an expensive design to make; and it protects much better and lasts longer than a standard filter."

 

Gotta say this post really helped with the task of replacing injectors. A couple of notes if u have access to a body work style porto power you will be thankful when pulling upper valve covers. Take a matter of minutes bracing on exhaust manifold. Only need light steady pressure and will separate after about 30 sec of stactic pressure. Also on driver side operating under master cylinder with universal adapter, about 1.5 feet of extensions, (using mutiple 6 inch gives a little more flex) and ball type allen makes bolt removal a cinch. Remember to follow torque specs when replacing as these bolts arent supposed to be reffed on anyway. Good luck and thank u for taking the time to help us all out