2015 3500 Denali Duramax

Merc63 said:

Ya truck is completely stock.

I get 18-20/100 around town depending how much it idles in winter warm ups. 23-25/100 pulling enclosed 4 place. 18-20/100 with 2 on th deck, depending on speed.

9th injector just went bad on me, truck keeps regening, gotta drop it off at dealer Monday, they have 10year warranty on that injector now.

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backsledder said:

Your lucky, what year is your truck? the 9th injector went out on my 2011 Chev, I was at 110k I had pay for it, no warranty after 80k. still a great truck, original brakes at 285k, still lots left, life time fuel average 16.5 l per 100 .

To the OP enjoy your truck, if you look after it you will get 10 plus years out of it.


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Merc63 said:

There is a special bulletin on that injector and 10 year warranty on it. cost me zero. Its a 2011 with 180 000km. all is good now, got it back and completed a regen.

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joshua335 said:

So what does the bulletin say? Just that there's a 10 yr warranty?

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backsledder said:

Big thanks for the information guys, I called the dealer that did the injector, and it looks like I will be getting almost 1000 $ back


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firstdoo said:

A bit of an update on the truck. I still love it. 59,000kms on it. (A lot more then I thought I would have on it by now). Fuel mileage is still doing great. I've even had it down to 9.4L/100 on the highway going to the lake empty. Only had a few minor repairs done so far. Fan clutch failed, sat antenna leaked.... 3 times lol. But the truck is in the shop right now. Rear diff had a slow leak that I couldn't find. Actually I didn't even know there was a leak until my last oil change when I saw the lube tech at the gm dealer with gear oil in his hand. Said it was down about half a litre. Booked it in for the repair before christmas and was kinda shocked to hear that the rear diff housing needed to be replaced. Leaking from the pinion seal due to a bad casting from the manufacturer, had to order of course. 2-3 week delivery. Truck will be ready today. I was surprised they didn't mention the air bags might be an extra charge for removing and installing (although I did work there back in the day).

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tex78 said:

Just a FYI for ya guys

Hitting the high frequency antenna with snow brush fawks it up

Have to wipe the snow nice in that area

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firstdoo said:

I'm gentle with the snow broom. Every time it leaked was in the summer during a good rain.

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tex78 said:

But the cause after first one is from broom

First ones lots got hit in the delivery truck

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firstdoo said:

I’m a bit confused here. I use a telescopic snow brush with 4” bristles. I don’t bang the crap out of the antenna. I brush it gently. Are you saying that if we properly clear snow off our trucks that we are going to damage the sat antenna???? So I should start being the douche with 2-5 inches of snow on the roof of my truck when I leave in the morning. Makes me think that GM has put out a really chitty product then if theirs is the only one that leaks from a snow brush. Sh*t, maybe I should trade it in on a ford or dodge now. Id hate to have to give up my Denali over a sat antenna.

The antenna leaked and was repaired. And then leaked again and was repaired. Once in the summer of ‘16 and twice in the summer of ‘17. I’m fairly certain that I wasn’t brushing snow off the roof between June and August.

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tex78 said:

Mabe they were not properly done


But hitting the antenna body side ways ( the narrow side, and bends the cab below it where it mounts) breaks the seal

Think the tsb if done now is to add some urethane around to help keep it sealed

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medler said:

If not from winter freeze and thaws also could be condensation on your roof Mostly vehicles with rear heat and vents in the headliner Or on star ant like Jeff says

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medler said:

Most likely it’s the sun roof drains being plugged. See it lots during freeze and thaws. Always good to sweep your roof off. Water freezes in the drains and drips through the headliner. It’s a bitch

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