gm, dealer or me

[tx dave]

Here goes guys, History: 01, lb7, love the truck. injectors @ 175K, now 225K and I got the bubbles in coolant and blowing of coolant. It started out small and got worst to the point I put in the shop ( a different dealer than the one who did the injectors) When it was taken apart we found the injector cup seal were not sealed on the bottom where they seat to the head, some of the brass washers on the bottom of the injectors were just plain filthy and some of the o rings on the injectors where crimped and nicked. I'm having everything (o rings, seals, cups, everything but injectors) replaced with new parts. The tech said this should of all been done during the warranty injector change. That said I'm out $2400.00. My ? Shoud gm help with this, or am i just SOL. A side note: I've used AMSOIL since I got the truck with 50k on it with duel filters and the inside of the valve cover and heads sparkled like new. I Love this Truck.

[Duramaster]

From experience, I have noticed that when the injector body o rings are knicked/ rolled there will be that burnt crusty oil at the base if the injector inside the sleeve. As far as did this cause the problem? who knows. You can try calling GM customer relations, but I don't know if that will get you anywhere.

[Mark Rinker]

Hello and welcome aboard!

Your problem, while regrettable, sounds very familiar. I had an '01 K2500 that got its first set of warranty injectors at 17XK miles, and then developed a pressurized cooling system, later in life. Sold it, as-is at about 260K IIRC, but always wondered if it was and injector cup seal from the warranty work, or a head gasket leaking...

Q: Have you ever run aftermarket performance tunes (more fuel rate) on this truck?

My opinion is that the '01 and '02 DMax were the best DMax trucks built - everything since has been a gradual, EPA mandated backslide...

[Duramaster]

And to add another note, the head gaskets were updated/ improved for the 2006 model year. The new gasket is riveted together instead of being crimped together. Also, on the injectors that had all the carbon and funk down in the sleeve, the sleeves usually pull with the injectors because the carbon build up is so great that it won't allow the injector to pull free of the sleeve.

[tx dave]

I have run an EDGE on 1 or 2. I pull a horse trailer and a 34' 5th wheel sometimes. The bottom of the injectors were slightly crusted, more so on the ones with the filthy brass washers. I plan to put 1,000,000 miles on this truck or wreck it. which ever comes first. I don't mind putting out the money to get it right I just feel let down by the tech who should of done a better job during the warrant work. I understand time is money for the techs.

[tx dave]

Duramaster, I've read all the things in here on the new head gaskets but I don't think it is a head gasket problem. I blew a head gasket on an 82 6.2 and all that psi actually blew the end off of my radiator. I do appriciate the replys and all the vas knowledge you guys give on this site. I feel I just needed to vent and to hear what all you more knowledgable than me folks thought. To me the unincumbered 01 LB7 is the best raw power DMAX built.

[DickWells]

Dave: I don't know where you're located, but just let me tell my experience, FWIW.
In summer, 07, I was beginning to blow black smoke at idle. Took my Sierra in to Sterling GMC in Longview, WA, with the Edge un-hooked, but still very visible. Talked to the service manager about it and he said, no problem. Two days later, I had all new injectors, And cups. I had ~75K on it at the time. The cost? $0000.00! Asked about the $100 deductable. Nope, doesn't apply for the injector system.
I realize that you're over the 7 years, but all that stuff should have been handled when your injector work was done. Routine, at Sterling. They even scoped my pistons/combustion chambers for flame cutting, etc., plus, they checked my valve lash. My feeling is, if you can find a dealer worth his salt, they should work with you to freshen up your engine like it should have been when the injectors were changed. Things have changed since 07, so you'll need some Lady Luck to help you find the right people.
Our best to you.
Dick Wells:)

[tx dave]

Dick, My original injector change was $0.00. I'm going back to the dealer tomorrow to try to get a copy of the invoice on this to see if any thing is mentioned about the cups and seals. If not I'll ask the new dealer if they can help me out or if they would know of any recourse. They seem to be on the up and up and the teck is an old biker who gives a hoot and seems to take pride in his work and believers if you do it, do it right.

[Mark Rinker]

Well, if they'll do the job over again, and you still have the bubbles, then you'll know it was a head gasket after all.

Chances are with an '01, that it is. Thats why the General updated the gaskets in '02 forward. Since you've towed with additional fuel rate, its almost guaranteed.

You might simply have them do the head gaskets, while they have it apart...

[DickWells]

Too bad you're so far from Del Rio. Brown Automotive has been just great for me. That's where I bought the Sierra, in Spring, 06.
DW

[madmatt]

During injector jobs,, if the cup doesn't come out it with the injector, doesn't get resealed. More then likely head gaskets on the 01s.

[tx dave]

Here's the update, all injector sleeves new, o-ring new, injector tips cleaned, put back together and whamo no change, still bubbles in the reservior. I'd say misdiagnosed. Anyway, today off comes the heads for new gaskets, This dealer service manager is a great guy, all the work so far will be rolled into the bill. Total Approx. 4100.00, including a new FPR which it's needed for a while. I think throught me being there twice aday and all the confersations, my knowledge of the engine and it's problems (thanks to this site and all you wonderful, knowledgeable folks) they have come to realize I could of walked off and did the job myself so I believe it ended up being either make a little money or NO money. I think I mentioned in an earlier post I have been working on engines (diesels, tractors, 6.2, 6.5 and 6.9 for a lot of years now, just not the DMAX. But I Love this truck. The cost is worth it to me to have new gaskets all new sleeves and seals and most of all a new dealer and tech I feel is trying to take care of me and not their pocket book. So many thanks to you guys out there (May the black smoke roll and roads be smooth. Dave

[Mark Rinker]

Dave -

I couldn't agree with you, more. The engine and the truck are worth the investment, especially if you consider the cost and uncertain availability of new.
The 2001 LB7 is a great engine, unincumbered by the emmissions requirements that have saddled it in subsequent years.

I wouldn't tow over 15K GCVW with the Edge tunes that I have tested. Too 'hot' (EGTs) and too much boost - high cylinder temps/pressures - although the stock LB7 has room for extra power to be safely added. Kennedy Diesel makes the best switchable tow/economy tune for the LB7 that I have ever tested, when combined with the Boost Valve to clean up the burn of the extra fueling, keeping EGTs in check. Sold both with my 2002, and doubt that I will have another Duramax powered truck that was as powerful, yielded as good mileage, and ran within the abilities of its cooling system and drivetrain componants. By comparison, the two LBZs owned today seem anemic in their stock trim (although power is rated high), perform poorly at the pump (especially unloaded mileage), and are operating on the edge of mechanical limits for cooling and torque converter capabilities, when turned up.

Good luck with the rest of the fix, and be GLAD you aren't attempting this at home... :)

[tx dave]

Thanks Mark, I hope all this work will give me the power back that I've lost over the years. The first thing I did when I bought the truck is a 4" exhaust, VOLANT Air intake with the down spout, ranch hand bumpers front and rear, B & W hitch. I monitor the egt and boost with the edge and I havn't yet seen the egt above 1200 or boost above 25. Of course I live in central Texas where the terrain is pretty flat or rolling hills, nothing severe. But thanks any way, when I get her back I'll monitor everything real close, Thanks again for all the help out there. dave