Dead miss cylinder #6
CF Active Member
Joined: Dec 2013
Posts: 138
Likes: 3
From: Genesee, MI.
Misfire on #6
Doktrred, I had the same problem on my 08 Suburban when it's engine had just over 130,000 miles. It was the same cylinder that had a misfire and turned out to be one of the hydraulic lifters. Just to remove and replace the two lifters cost me $1200. Tough to swallow because the two parts that failed cost less than a hundred bucks. Labor, gaskets, seals, and oil change was the other $1100. Depending on how many miles you have on your engine will likely play a role in what you decide to do. But, if it helps you, my engine ran fine and strong until this past month when I got a misfire on cylinder #4. It turns out, the likely problem this time is another faulty hydraulic lifter. I got another 150,000 miles out of my engine before this recent failure. This time I am going to do the work myself. I don't owe anything on my Suburban. So, I figure spending the $500 on a lifter replacement kit is worth fixing it. Closing in on 300,000 miles and the Suburban itself inside and out is in fine shape. So, its well worth the effort for me. Hope you can decide on what's best for you. Best of luck and may you still have a little cash left to celebrate once it's repaired.
Administrator
Joined: Apr 2008
Posts: 7,573
Likes: 47
From: Austin, Texas
Doktrred, I had the same problem on my 08 Suburban when it's engine had just over 130,000 miles. It was the same cylinder that had a misfire and turned out to be one of the hydraulic lifters. Just to remove and replace the two lifters cost me $1200. Tough to swallow because the two parts that failed cost less than a hundred bucks. Labor, gaskets, seals, and oil change was the other $1100. Depending on how many miles you have on your engine will likely play a role in what you decide to do. But, if it helps you, my engine ran fine and strong until this past month when I got a misfire on cylinder #4. It turns out, the likely problem this time is another faulty hydraulic lifter. I got another 150,000 miles out of my engine before this recent failure. This time I am going to do the work myself. I don't owe anything on my Suburban. So, I figure spending the $500 on a lifter replacement kit is worth fixing it. Closing in on 300,000 miles and the Suburban itself inside and out is in fine shape. So, its well worth the effort for me. Hope you can decide on what's best for you. Best of luck and may you still have a little cash left to celebrate once it's repaired.
I would suggest doing all of the AFM lifters if you are going to go through the trouble of pulling the engine apart... also install the upgraded valve cover and AFM deflector hood in the oil pan if its not already installed.
CF Beginner
Joined: Apr 2021
Posts: 1
Likes: 0
Miss fire 6 and 7 no running compression
I have a 2009 Silverado with 182000 miles. I have had all the lifters replaced, Heads resurfaced, changed plugs, ignition coils and 1 fuel injector. I still have a misfire on 6 and 7 with no running compression. It does have start up compression. Not sure what else to do with this truck. Any ideas will be helpful.
CF Beginner
Joined: Feb 2024
Posts: 1
Likes: 0
Misfire after replacing oil pressure sensor
2007 suburban 5.3L flex .
I was driving to work this morning and all of a sudden got warning chime and flashing ck. engine light, and stability trac service light came on(which it has done numerous times in past usually while stopped at a light. Truck felt ok but did notice oil pressure was around 32psi vs 40 which it typically is. Had replaced the oil sensor about 1 1/2 yr ago. It wasn't till I got to towm and rpm's lowered that I felt a miss. The tranny shifting wasn't as smooth but wasn't a hard shift. I didn't have time to look at it this weekend, so took to a mechanic I've used before. He got following codes:
PO306 #6 cylinder misfire
PO 121 Throttle position peddle sensor (range)
PO521 Oil press. sensor (range)
PO451 evap (that's been a code I've known about for a while that I never did fix)
He tried replacing plugs, and wires. I think he said he switched coils??? on adjacent cylinders? Pressure on #6 was 75 and about 100psi on other cylinders. So he's not for sure whats wrong at this point without removing head. Wondered if anyone had seen these sets of things happen all at once in a vehicle that's run like a top for years
Thanks,
Mike
I was driving to work this morning and all of a sudden got warning chime and flashing ck. engine light, and stability trac service light came on(which it has done numerous times in past usually while stopped at a light. Truck felt ok but did notice oil pressure was around 32psi vs 40 which it typically is. Had replaced the oil sensor about 1 1/2 yr ago. It wasn't till I got to towm and rpm's lowered that I felt a miss. The tranny shifting wasn't as smooth but wasn't a hard shift. I didn't have time to look at it this weekend, so took to a mechanic I've used before. He got following codes:
PO306 #6 cylinder misfire
PO 121 Throttle position peddle sensor (range)
PO521 Oil press. sensor (range)
PO451 evap (that's been a code I've known about for a while that I never did fix)
He tried replacing plugs, and wires. I think he said he switched coils??? on adjacent cylinders? Pressure on #6 was 75 and about 100psi on other cylinders. So he's not for sure whats wrong at this point without removing head. Wondered if anyone had seen these sets of things happen all at once in a vehicle that's run like a top for years
Thanks,
Mike
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