2015 Silverado 5.3L v8

[Josh Guidry]

yes, i currently drive a 2015 silverado LT 5.3L v8, looking for answers with the AFM/DOD issue.

                      i have a single cylinder misfire currently on my cylinder 5, it creates only 140 lbs of pressure PSI, when all other cylinders are firing properly at 200+ PSI. so, i am thinking that it could be a maintenance issue. so, i recently discovered that my spark plug ( brand name an new) was bent from the firing ring.. So, me figuring it could be the top of the maintenance where it could be coil packs, spark plugs and coil wires. So, I eliminated that  out. Then, i am looking deeper into that it may be a fuel injector issue, turns out it is not that either but i was giving the impression that it could be my camshaft or cylinder heads and that it would consider making mechanical damage to my heads and creating more of a head and cam shaft issues and also trying to reach out to my fellow 5.3l silverado owners that may have the same problem and also be given a better insight on what causes the heads to not be properly function with low compression and what would the root problem could be. i do not want to dig into labor costs and just start throwing money into a specific problem. if anyone has any insight on what causes low compression to single cylinder misfire, please powertrain warranty is out from 100,000 mile which is typical but i am hearing that from the AFM DOD engine 5.3 has these exact same issues and i want to find the main problem to it! my email is [email protected] and i respond fast. dealerships and auto shops are turning away from me because i was told there is allot of work to do with this and this is super commonly problem but just trying to find out who might could tell me a better insight that i could diagnose as well or may take to find out more of the issue. it is gonna cost me $9,668.75 for new engine with the AFM DOD system but i was also have no warranty with it because it ran out at 79,999 miles. so out of pocket i cant afford . was thinking extended powertrain warranty or something. Also, trying to see how long a typical ext warranty would take for it to take into effect too idk maybe try to put it in the shop trying to find out my options on what i could take a look at in order to diagnose it myself because isnt cheap and i just wanna try to find assistance thru gm since i cannot get a ext warranty to replace an engine. nobody wants to just buy a brand new engine unless they're just full of money. if any info will surely help me out allot.

[newdude]

Cylinder 5 is not an AFM cylinder.  So its not that.  Doesn't mean the cam and lifters didn't go though.  Need to do a cylinder leakdown test, possibly stick a boroscope down the spark plug hole and see if the piston is damaged.  

[newdude]

Just noticed you said the spark plug was bent?  Was it bent at the electrode (aka in the cylinder)?  If the plug was damaged in the cylinder, there is debris in there from a valve touching a piston or debris from a ring.   

 

Also GM won't assist unless a dealer does a full diagnosis and estimate, and then you would have to ask the service department if GM can do anything with it.  If they say no, start a case with customer assistance and then go from there.  

 

[newdude]

On 4/22/2020 at 1:54 PM, Josh Guidry said:

 

 

 

Any updates?  I see you last were here when you started this post.