Stabilitrak issue my journey so far.

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Taheezy_88

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no more p0621 i pulled alternator the other day and had it checked before replacing plugs and wires.
 
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Taheezy_88

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Pulled #4 plug earlier checked gap, and reseated the plug wires also. Still misfire but now just p300.

The knock is a knock and louder with rev up. It isn't no tick sound its a knock guys. How can I post a vid?
 

Just Fishing

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Youtube, then post a link or imbed the video using the little button when posting: upload_2021-2-20_17-35-57.png

and that service stablitrack crap comes on with just about everything.
Usually something disconnected.
me not plugging in my displacement on demand connector on the back of the engine vally cover triggered that, along with ABS errors for some strange reason.

Also if you moved your throttle body butterfly while say cleaning it...
That will also trigger all sorts of errors.
I had that surprise when i put my engine back together. :rolleyes:
 

iamdub

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Pulled #4 plug earlier checked gap, and reseated the plug wires also. Still misfire but now just p300.

The knock is a knock and louder with rev up. It isn't no tick sound its a knock guys. How can I post a vid?


Uploading to YouTube and posting the link is all I know for posting vids.

Check the dipstick for sparkles in the oil and rub it on a white napkin to see if there's anything alarming. Pop off that passenger side rocker cover and see if you have a limp rocker. If you have a lower end knock, it may be too late. Sometimes a collapsed lifter can sound like a knock, especially if it rotated.
 
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Taheezy_88

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Pulling apart today. Opting for maybe a new engine instead of rebuild.
 

jj88

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Did you calibrate your PCU when you got the 33" tires? stock tires are 31.6" in believe. I will be using this speedo calibrator soon myself. I think I read somewhere that 3% off in diameter will set speed sensor codes, and other things connected to wheel speed sensors, etc. I'm hoping the speedo calibrator will fix this.

hypertech speedo calib.png

http://www.hypertech-inc.com/vehicle-results.aspx?AAIAID=188054
 

1BADI5

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Sadly, tire size going to have nothing to do with a misfire.

If your 900 is a 2010, more likely then not you have a LMG 5.3, so you will have VVT and AFM/DoD.

IF you go about replacing the motor, I would recommend buying a long block from a quality/well known shop. It will cost you alittle bit more up front, but will last longer then a used motor. Got one that has had the VVT and AFM removed and you'll be on easy street....but it will require a tune to run.
 

wsteele

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Sadly, tire size going to have nothing to do with a misfire.

If your 900 is a 2010, more likely then not you have a LMG 5.3, so you will have VVT and AFM/DoD.

IF you go about replacing the motor, I would recommend buying a long block from a quality/well known shop. It will cost you alittle bit more up front, but will last longer then a used motor. Got one that has had the VVT and AFM removed and you'll be on easy street....but it will require a tune to run.

I think he said his rig is a 2007, so yes on AFM, no to VVT.

I agree on the quality long block, he can buy a reman for around $3K (plus core), some offer AFM Delete as part of the package and include a Diablo Predator to turn off AFM in the PCM after the engine is in the truck.
 
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Taheezy_88

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Quick update guys and thanks for the replies.

I pulled intake manifold, and valve covers. Driver side rocker arms and rods look good all intact.
Passenger side I have one loose rocker arm above cylinder 4 where I was getting a misfire.
First pic is drive side and second is passenger. My finger is where the loose rocker arm is at.

Being as far in the tear down should I opt for the AFM DOD delete? Or replace rockers and rods?

Side note: I was having oil pressure issues before this happened. What replacement route to fix that issue? New pump or just the oil sending sensor deal in the back of the manifold?

20210224_130350.jpg 20210224_130332.jpg
 

iamdub

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Quick update guys and thanks for the replies.

I pulled intake manifold, and valve covers. Driver side rocker arms and rods look good all intact.
Passenger side I have one loose rocker arm above cylinder 4 where I was getting a misfire.
First pic is drive side and second is passenger. My finger is where the loose rocker arm is at.

Being as far in the tear down should I opt for the AFM DOD delete? Or replace rockers and rods?

Side note: I was having oil pressure issues before this happened. What replacement route to fix that issue? New pump or just the oil sending sensor deal in the back of the manifold?

View attachment 271728 View attachment 271729


Since the intake manifold is off, check the VLOM bolts to make sure they're tight. It's also a good time to replace that oil pressure sensor and clean or replace the screen under it. The sensor may not be bad, but it's really hard to access with the manifold in place. A loose VLOM can cause low oil pressure and a failed AFM lifter. A leaky O-ring is another common cause for low oil pressure, but you can't check that unless the engine is running.

As far as the rocker, you gotta determine why it's loose. Is the pivot bolt loose? Is it slack between it and the push rod (collapsed lifter)? If a collapsed lifter, and since the the VLOM is accessible/removable, you can try this trick:



Try to see if that lifter isn't turned and if the cam lobe is ok. If so proceed with trying to unstick the lifter. If that fixes that, disable AFM ASAP! You can get it disabled in a tune for $50 plus the shipping of your PCM.

You're really not that far into an AFM delete. If I had to put a number on it, I'd say you're around 15% "there".
 

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