2013 PPV Slight Idle Shake Unknown Cause

Well there are a number of things that come to mind here and some are simple things you can do as an owner.

1) we know the AFM is garbage and prone to lifter issues; I put 8 oz of seafoam in the oil for about 250 miles before my oil change to clean the junk out. Those small oil passages on are the issue if the vehicle did not have regular oil changes. I have seen this free up a bad lifter ( its cheap and worth a shot)

2) Motor mount(s) replacement is a common problem with the GMT900s, verify there the mounts are solid, if cracked or have excessive play; replace them(easy job) (mine were replaced at 65K)
3) Transmission mount (see #2)
4) Verify your fuel pressure at the rail, if the pressure is good, you might have a gummed up injector(s)

As a part time tech this is where I would start.

State_Blue_Man said:

All thanks for the input and I think I’ll invest in a tech 2 and run some tests and watch the read outs.

I do understand the service advisors position but it’s frustrating when I’m about to put down $100 to schedule an appointment and not be able to feel confident in the dealer and it’s technicians. So I’ll try again at another Chevy dealer and maybe get in sooner than 2 weeks.

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You don't need a Tech2. The scanning can be successfully-completed by yourself so you get the current, valid, codes to work with.

I've used an ELM327 Bluetooth OBDII module with their ELM327Checker app on our '10 PPV and '12 9C1. I have the apps installed on our Galaxy Tab 4 tablet, but both have iDevice apps. I think the module was less than $100, and has been very useful.

When it came time to read chassis codes, I had to step up to the Bluedriver OBDII Bluetooth scan tool module and their app. The app, as usual, was free, and I think I paid about $100 for the scan tool. Both have paid for themselves if for nothing more than not having to hassle with the dealer for codes the parts house couldn't find.

Invest in one of these. I'd go with the Bluedriver, because it will scan, and clear, traction control and ABS system errors.

The apps for both will even post links you can follow for more info on each code posted.

I even know of a guy on another forum who is trying to sell his ELM327 for the price of shipping:

http://www.newcaprice.com/forum/viewtopic.php?f=32&t=3349

Do it!

State_Blue_Man said:

Please keep me posted on the results of your findings.

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sorry for the delay, but my scanning method is not giving any codes. I am blaming the scan tool at the moment, but it may be the range technology device.

I need to run it without the range device for a bit and see if that yields the misfire codes I am expecting.

If you have the DIC buttons in your Tahoe (I would make the cheap investment if you don’t) , switch the instrument gauge to where you see the V8 or V4 mode. Drive around and see if the shake happened the same time it switches from V8 to V4 .

I did the AFM/DOD delete as I was having a similar problem after changing motor mounts, trans mounts, spark plugs (#8 plug is horrible), and bunch of other stuff and still had the same problem. After the AFM/DOD delete using my DiabloSport tuner... no more shakes.

Thanks will check that out, yes been thinking of afm delete... does it leave check engine light on?? Not a dealbreaker but just wondering

foeteef said:

Thanks will check that out, yes been thinking of afm delete... does it leave check engine light on?? Not a dealbreaker but just wondering

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Well if you do a full blown AFM delete, you will need a tuner to go in and turn it off. I know with HPTuners its a super simple function to perform, but keep in mind it will still cost you $250-500 for the tuning. (Note: HPTuners $200 of that cost is just for the credits to access the VIN for tuning)

State_Blue_Man said:

P015B bank one sensor o2
P219A fuel bank 1 imbalance
P219B fuel bank 2 imbalance

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Those last two are fuel trim codes, lean or rich. That certainly doesn't narrow anything down for you, but since its on both banks of the engine its likely a central source. IMO you are chasing your tail looking at oxygen sensors, I'd be looking at the MAF to see if it has anything stuck to it. Does your truck have CAI or anything? I'd also look for simple intake-side leaks, especially between the MAF and throttle body (intake boot, clamps, etc).

1BADI5 said:

Well if you do a full blown AFM delete, you will need a tuner to go in and turn it off. I know with HPTuners its a super simple function to perform, but keep in mind it will still cost you $250-500 for the tuning. (Note: HPTuners $200 of that cost is just for the credits to access the VIN for tuning)

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$100 to unlock the VIN.

I'm going to run my codes tomorrow and post. No check engine light, but I know it can still ha have stored codes.

RichardCranium said:

$100 to unlock the VIN.

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Yes, Sir.......you're correct

Well sorry for the delay in posting. But ran codes several times. None found. Check engine and transmission codes. Nothing . Used two different good scanners. OTC Genisys touch and Autel maxsys 808. Again mines sound like a light exhaust leak on right/passenger side. Have examined all over manifold and where manifold meets pipe.
But I dont think it would be that because noise and sluggish/hesitation, almost dead spot, is same time frame with rpm. Thinking of buying those diablo delete. I know its not a full delete but to see if noise/hesitation stops I'll know it's with afm or lifter tick issue. ???