Update: 07 Sierra Smoking

[Danielmattingly]

I posted awhile back about my 2007 Sierra 5.3 NBS burning oil

 

If you kept your foot off the throttle while coasting down a hill at least half a mile or more & when you came back on the gas the truck would leave a 30' or so trail of blue smoke & the longer it would coast after half a mile the more smoke you would get when you got back onto the throttle then it would clear up & never do it again

 

I've been told valve guide seals,plugged pcv,worn rings,lifters,heads etc but one bit if info I heard was about the AFM or DOD...Was a huge PITA getting a tuner this week..I thought about blackbear but for what I need a Tuner would be a smarter choice.. I simply just wanted to turn off the AFM..I hated it since I bought the truck..& when I trade in again I"ll set it back to the factory settings & use my tuner on my New Gm..anyway I was hoping it would perhaps cure the blue smoke issue...Well I finally got it today & turned off the Afm & guess what? No blue smoke anymore.....

 

As far as the oil it was consuming I'll find that out in a couple weeks & I'll add another reply to this post about that..

 

I dont mind it burned a quart every 4k just as long as it doesnt smoke..

[punmax]

That's good to hear! Keep us posted about the oil consumption issue.

[asilverblazer]

Sounds like you need new lifters. When they get pumped full of oil to run in V4 mode (like when coasting) they are letting oil into the cylinder. When you get back on the gas the oil gets burnt off. They probably leak all the time but those cylinders not firing are letting it build up. Now that they fire all the time it gets burnt off. I bet consumption will stay the same, still leaks, still needs fixed, just no more build up creating smoke.

[Danielmattingly]

1500 miles so far with AFM turned off & oil has not moved a hair on the dipstick....

 

Before it was bout a quart every 4k..I would think it would be down alittle bit on the dipstick by now..

 

 

I'll keep an eye on it..Lately with Mobil 1 I"ve been changing it bout every 6k.. I'm not driving alot this month so it'll be awhile before I get another 4500 miles on it..

 

Will give another update in bout another month or less

[ajcain79]

Why not let the warranty repair your truck before the warranty expires then put the runer back on it? When the AFM bites the dust later on, you might be facing a huge out of warranty repair bill, AFM turned off or not.

IIRC he is past his warranty period.

[Zembonez]

I agree. If it doesn't smoke with the AFM turned off, I'd just keep on driving. Hopefully the oil consumption will diminish as well. Please keep us posted.

[Danielmattingly]

Why not let the warranty repair your truck before the warranty expires then put the runer back on it? When the AFM bites the dust later on, you might be facing a huge out of warranty repair bill, AFM turned off or not.

IIRC he is past his warranty period.

 

 

More then 100k on the 5year/100k powertrain?

 

 

 

The Truck was one of the few before the 5year100k..I bought it with a 3year36000.... Either way it doesnt matter Its got 160k on it now..I think its well past ;)