2001 LB7 duramax issue

[gmc sierra]

134,00 miles

On ocasions While driving service engine light will come on, truck will lose power- on flat ground 65 mph max-up a grade speed will decrease and not increase until i catch a down grade- stop for a toll maybe 30 mph max. pull over shut down and restart ,everything good. However it will do it again with more frecuency between restarts. The first time it happened had it look at where I bought the truck no codes appeared. Anybody out there have any thoughts or experiences of the same nature. Thanks Mike.

[lmholmes11]

I would start by changing fuel filter. A bad fuel filter will often cause symptoms like you described. Is there any white smoke at all coming from the truck? If there is, and it is white it is most likely injectors, however you said the truck didnt throw a code, and I'm pretty sure most injector issues will throw a code. I also have an 01' and my truck was going into 'Limp' mode just as you described. Changed fuel filter, still did the same thing, took it in and had all the injectors replaced (under warranty thank god). Since your truck isnt in the warranty window, an injector job will run on average $4,500. Unless you know how to do it yourself.

[ScubaAl]

My injectors are being replace right now. Truck has been at the dealer since Monday. Waiting for the injectors to arrive. Cost they quoted me, $5300.00. This is on a 2002 out of warranty.
Not Happy, Al

[gmc sierra]

All filters are always in good shape, truck runs great 98% of the time except when this problem ocurrs.

[lmholmes11]

Does your truck do this during city driving or highway driving or both? When my injectors went bad my truck only went into limp mode on the highway. City driving presented no problems. I'm not saying this is always the case but it is what I went through. Given your truck is an 01' with 132,000 miles on it I would get the injectors tested anyways. If they have not been changed out, and the symptoms you are describing are not caused by the injectors after all, they are going to need to be replaced soon anyways...

[leolkfrm]

call gm customer service yourself and try and get some help!

[gmc sierra]

It was the injecters. Trucks is 8.5 years old 135,000 miles, so I called GM customer service(so did the dealership were I bought the truck and had the woek done) to see if they would cover the warranty. GM agreed to pay for the injecters (over $2,100.00 US), that was half of the total coast. ScubaAl give GM a call (1-800-462-8782). The dealership played a big part in getting GM to pay some of the bill.

[Mark Rinker]

Wow!

I just got rejected for my 2006, at 101K. First problem reported and were documented at a GM dealership that recommended replacement, under 100K miles. Consider yourself fortunate - GM has been tightening their requirements, and denying many claims over the cutoff. To your observation, I had no dealership pulling for me. My hometown dealership was closed as part of the GM shuttering.

Q1: Did you buy the truck at the same dealership where the warranty work was done?

Q2: Did anyone ask you if you bought the truck new, vs. used?

[gmc sierra]

This is an injector design issue for the first generation of the duramax LB7 motor. GM extented the warranty to 7 years-200,000 miles for that one issue only. Your injector problem would not have the same kind of consideration from GM once your warranty expired.

[Mark Rinker]

Glad to see they are still standing behind the LB7s. The General bought me four free sets for my '01, '02, '04 LB7s, I am probably due to get out my checkbook, the next time...ya think? ;)

My current 2006 loads up a bit if you let it sit, idling. No smoke while it idles, but at take off, a smelly cloud of unburned fuel that settles in the catalytic converter and muffler. It will also set a low fuel rail pressure code under high demand - i.e. heavy towing in hot temps in the mountains. Normal driving and towing, the mileage and power are unaffected. Hoping to get 50K or so more additional miles - before biting the bullet for a new set of sprays.