2015 5.3 Silverado Cyl #5 misfire

jasonhooker3 · April 12, 2022

2015 5.3 Silverado with 84k miles recently developed a lifter tick around 2200-2300 rpm. Tick occurs in gear and out of gear at same rpm. No noise under 2200-2300 rpm and truck drives perfect. During acceleration (on ramp or passing) tick becomes louder (starting at 2200-2300) until approximately 4000 rpm where engine misfires, drops cylinder and throws a code. Scan tool shows P0305 code (cyl #5 misfire) only. Changed plugs, swapped coils and misfire stays at cyl #5. #5 is not a DOD lifter. Wondering if anyone has or had the same issue and what you did to resolve it. No warranty left, next step is to pull the cylinder head to further diagnose. If it turns out to be lifter, Im guessing I'd have about $1k in parts to replace. Dealer quoted $3500 to tear into it and diagnose. Service advisor said GM may or may not kick in any $$ for "goodwill" since truck is recently out of warranty and lifters are common issue? Thanks for any feedback

Snowcamo · April 12, 2022

Change the oil and try This first. Between that and cleaning my coil to plug connections resolved my lifter tap. Honestly this was it more then the ignition. Then again I didn't drive too far when the engine started to tap.

That said, when I was finished I went on a 175 mile ride and all has been well since.

CamGTP · April 12, 2022

I'd start with a fuel injector before I pulled the cylinder heads.

If it's not the spark plug, wire or coil pack. Then you are down to compression and or the fuel injector.

It's Tim · April 12, 2022

Agreed.

Compression and/or leak down test on all cylinders.

BlancoSilverado · April 12, 2022

Sounds like your on the right track. Does this happen when the engine is cold/cool or when its fully hot?

Compression and leak down test, then if that comes out good, i would then run a cleaner (like seafoam) though the intake to possibly remove carbon build up. Since these motors are DI that could (might not) be an issue, also usually carbon build up problems show up on a cold engine.

jasonhooker3 · April 12, 2022

Engine temp does not change anything, it happens hot and cold. Also pulled driver side valve cover, removed rockers, pushrods and everything looks good. Put it back together and started engine with valve cover removed and everything looks okay but the front rocker on #5 did not feel as smooth as all the others, I believe it was the intake. Not sure how else to describe it.

Edited April 12, 2022 by jasonhooker3

jasonhooker3 · May 4, 2022

Took truck to dealer, discovered #5 lifters were pitted and cam was junk. All new lifters and new cam $8,900. Service advisor said he contacted GM who agreed to pay nearly half, I am responsible for $4600. FML... Sounds like I'm paying for everything and they're just lubing me up by jacking up total and saying GM is kicking in half when that is BS.

jasonhooker3 · May 4, 2022

Reputable shop in Torrance "Bothwell Automotive" said its a 26 hour job and should be $4500 including parts

CamGTP · May 4, 2022

Yup, that's a dealership for ya. Super high labor rates and very high mark up on parts.

My parents had to get 2 lifters replaced on cylinder 7 last summer, it was a $2,000 job at a local shop I know very well. It would have only been few hundred more dollars to replace the rest of the lifters on that side and the full job would have been in that $3,500-4,000 range.

That price isn't including a camshaft replacement though.

Edited May 4, 2022 by CamGTP