2012 Burb 5.3 Rough Idle

orange150

orange150

Well-Known Member
Joined
Mar 20, 2005
Location
Fairfax City, VA
The family truckster has started idling kinda rough. Not rough enough to throw a code but you can definitely feel it and see it on the tach. Anything I should be on the lookout for? It's just shy of 155k on the clock and received new plugs and coil packs within the past 25k miles but is otherwise unmolested.
 
orange150 said:
The family truckster has started idling kinda rough. Not rough enough to throw a code but you can definitely feel it and see it on the tach. Anything I should be on the lookout for? It's just shy of 155k on the clock and received new plugs and coil packs within the past 25k miles but is otherwise unmolested.
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What's the status of the AFM?
 
If I had a truck with GM's AFM, I would definitely tune it off, or get a quick obd plug and play override.

My money would be on intake gaskets. Might put an eye on your rear most knock sensor while you are in there.
 
LBarr2002 said:
What's the status of the AFM?
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shelby27604 said:
If I had a truck with GM's AFM, I would definitely tune it off, or get a quick obd plug and play override.

My money would be on intake gaskets.
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AFM is intact and burning oil just as GM intended.

I've thought about getting a "tuner" or whatever I can plug in and turn that off, I've read about the throttle response you can tune in (or out?), anything to maybe help with fuel economy. I've also read about an afterblower function that you can turn on through a tuner to help alleviate smells from the condenser box, which my wife complains about constantly that I've yet to smell.
 
If you aren't going to do the full delete, you should invest $150-$200 on a plug and play delete. The lifters fail when going from cylinder off to cylinder on. The locks get galled up and don't allow the lifter to return to normal operation.

There are some success stories with forcing them to return to normal, BUT they are not the norm.
 
orange150 said:
AFM is intact and burning oil just as GM intended.

I've thought about getting a "tuner" or whatever I can plug in and turn that off, I've read about the throttle response you can tune in (or out?), anything to maybe help with fuel economy. I've also read about an afterblower function that you can turn on through a tuner to help alleviate smells from the condenser box, which my wife complains about constantly that I've yet to smell.
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The guy that I have tune everything ups the idle rpm 50-100 just to smooth that out. I don't have anything with AFM any more, but same guy turned off AFM on my mom's 2007 5.3 and upped the idle a little. Virtually stopped the oil consumption and mileage didn't suffer much. Also, the oil burning killed the cats.

What I was getting at is I hope you don't have a cam or lifter issue. Intake leak is a good suggestion and a much cheaper problem to solve.
 
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