Thoughts on AFM Delete

[Mizz0313]

Buddy just purchased a 2009 chevy silverado for 1500 bucks with 180k. He works for culligan water and the truck was a company vehicle. 5.3 rwd, a little rust as we are in PA but overall a solid truck and runs fairly smooth. The first time he drove it home before buying I looked it over and listened to it run, all looked good. Later that day the engine light came on and i immediately pulled out the scanner, P0300! Misfires on 1 and 6. Light went out the next day and stayed off for about 4 days before returning and repeating the same cycle. I will start diagnoses on this truck by first doing a compression test and possibly pulling valve covers on effected banks. I should assume this code can be from anything but in my experience of my XL the p0300 ended up being a few collapsed lifters and a bent push rod on 7, it was in a lot worse condition. If it is internal, it sounds as if the lifters are sticking, what are your thoughts about deleting AFM from tune? If the lifter is unstuck and light is off would it be a good time to delete tune? We have the options of either updating components from GM tsb in hopes of saving the lifters from collapsing or deleting AFM completely like I did in the XL but do you think deleting tune on a fairly decent running motor will allow it to last for a decent amount of time? Wondering if this would be a option other than engine tear down if diagnoses points to something internal when light is on. Thanks and all feedback is welcome.

 

[swathdiver]

Buddy just purchased a 2009 chevy silverado for 1500 bucks with 180k. He works for culligan water and the truck was a company vehicle. 5.3 rwd, a little rust as we are in PA but overall a solid truck and runs fairly smooth. The first time he drove it home before buying I looked it over and listened to it run, all looked good. Later that day the engine light came on and i immediately pulled out the scanner, P0300! Misfires on 1 and 6. Light went out the next day and stayed off for about 4 days before returning and repeating the same cycle. I will start diagnoses on this truck by first doing a compression test and possibly pulling valve covers on effected banks. I should assume this code can be from anything but in my experience of my XL the p0300 ended up being a few collapsed lifters and a bent push rod on 7, it was in a lot worse condition. If it is internal, it sounds as if the lifters are sticking, what are your thoughts about deleting AFM from tune? If the lifter is unstuck and light is off would it be a good time to delete tune? We have the options of either updating components from GM tsb in hopes of saving the lifters from collapsing or deleting AFM completely like I did in the XL but do you think deleting tune on a fairly decent running motor will allow it to last for a decent amount of time? Wondering if this would be a option other than engine tear down if diagnoses points to something internal when light is on. Thanks and all feedback is welcome.

If you have a Tech-2 or equivalent you can test the VLOM solenoids to see if they're the problem of the collapsed lifters. They usually are. The solenoids need at least 15 psi of oil pressure to operate properly and if that little screen under the oil pressure sensor gets clogged, it can mess up the timing.

 

[Mizz0313]

If you have a Tech-2 or equivalent you can test the VLOM solenoids to see if they're the problem of the collapsed lifters. They usually are. The solenoids need at least 15 psi of oil pressure to operate properly and if that little screen under the oil pressure sensor gets clogged, it can mess up the timing.

I do not have a tech 2 but I think my cousins snap on will work the solenoids. I have done a fair share of research on upgrades to keep AFM and the vlom was one thing I found to be a issue as well as the oil pressure filter under sensor. I have kept a close eye on his pressure and it seems to be where it needs to be during idle and normal driving but I have put a new vlom on the list of purchases if we move towards GM tsb fixes. Trying to replace anything that may be a factor in killing off the lifters if he decides to keep AFM for a while. Thanks.

 

[swathdiver]

I do not have a tech 2 but I think my cousins snap on will work the solenoids. I have done a fair share of research on upgrades to keep AFM and the vlom was one thing I found to be a issue as well as the oil pressure filter under sensor. I have kept a close eye on his pressure and it seems to be where it needs to be during idle and normal driving but I have put a new vlom on the list of purchases if we move towards GM tsb fixes. Trying to replace anything that may be a factor in killing off the lifters if he decides to keep AFM for a while. Thanks.

Replacement of the VLOM and the lifter guides is SOP when replacing the lifters and doing an AFM repair. Don't forget the updated valve cover on the driver's side to reduce oil consumption. At that mileage, might as well replace the oil pump's pick up tube o-ring too.

 

[Mizz0313]

Absolutely! Hoping to not go that far in the motor just yet. My hopes is we can do the valve cover, vlom and filter, oil pan deflector and I even went as far as saying new oil pump and oring while im in there. It would really suck to do this work only for a lifter to fail anyhow. Will see the responses I get about just leaving the motor as is and tuning afm out until something goes out then we can do a full delete.