06 2500 6.0 66

[pm gm]

Hello, I have a 06 silverado Hd with 6.0 66,xxx miles and I have a misfire issues on cyliders #1 and #8 the rest of the cyliders are cool. I have changed plugs,wires, swapped coils around and checked the injectors ( by swapping 1 to 3 and 6 to 8 with no change). I have been reading up and I'm starting to think it's cam and lifter failure. Truck has a slight miss at idle and hesitation off the line but smooves out at the higher rpm. The truck is currently parked while I figure out whats wrong with it and snowplow season is right around the corner. If anyone one here can help me out with what I need to check out next, I would gladly appreciate it..

 

Thanks

Pernell

[Gregs]

have you cleaned the maf? i had a misfire problem the other week and after checking everything it ended up being a dirty maf. I think a valvetrain failure is not very likely but you never know

 

checked fuel pressure? also which codes is if showing? Are they saying cylinder X misfire or are you determining the misfires by viewing the misfire counters on a scan tool?

[06_GMC]

I agree sometimes those MAF's can cause all sorts of problems.

[pm gm]

have you cleaned the maf? i had a misfire problem the other week and after checking everything it ended up being a dirty maf. I think a valvetrain failure is not very likely but you never know

 

checked fuel pressure? also which codes is if showing? Are they saying cylinder X misfire or are you determining the misfires by viewing the misfire counters on a scan tool?

 

 

Yes.. I used a snapon scanner that shows current cylinder misfires.. This is how it looks.

 

 

MISFIRE _________ HISTORY

CYL 1____ 38 ____ 135643

CYL 2____ 0 _____ 21

CYL 3____ 0 _____ 335

CYL 4____ 0 _____ 14

CYL 5____ 0 _____ 60

CYL 6____ 0 _____ 54

CYL 7____ 0 _____ 0

CYL 8____ 1 _____ 3817

 

While the engine is running you only get misfires on #1 and #8 all the rest are ok. I checked the fuel pressure that was good and I also cleaned the maf. The truck starts right up no hard starts or anything it just has a slight miss at idle.

 

Engine codes were.. p0300, p0200

 

Im new to these motors but they seem to be alot easier to work on the gen 2 engines, so if you guys can tell me what to check next i can do it and report back my findings...

 

Thanks

Pernell

[Gregs]

have you cleaned the maf? i had a misfire problem the other week and after checking everything it ended up being a dirty maf. I think a valvetrain failure is not very likely but you never know

 

checked fuel pressure? also which codes is if showing? Are they saying cylinder X misfire or are you determining the misfires by viewing the misfire counters on a scan tool?

 

 

Yes.. I used a snapon scanner that shows current cylinder misfires.. This is how it looks.

 

 

MISFIRE _________ HISTORY

CYL 1____ 38 ____ 135643

CYL 2____ 0 _____ 21

CYL 3____ 0 _____ 335

CYL 4____ 0 _____ 14

CYL 5____ 0 _____ 60

CYL 6____ 0 _____ 54

CYL 7____ 0 _____ 0

CYL 8____ 1 _____ 3817

 

While the engine is running you only get misfires on #1 and #8 all the rest are ok. I checked the fuel pressure that was good and I also cleaned the maf. The truck starts right up no hard starts or anything it just has a slight miss at idle.

 

Engine codes were.. p0300, p0200

 

Im new to these motors but they seem to be alot easier to work on the gen 2 engines, so if you guys can tell me what to check next i can do it and report back my findings...

 

Thanks

Pernell

 

 

i see, well the p0200 code is probably whats causing the p0300. your probably going to need to get a hold of a wiring diagram and start checking continuity on the injector harness. also you could check and clean the pcm wiring harness connections.

 

Just an FYI: you have to remember that the misfire counters on a scan tool aren't very accurate. the computer detects a misfire when the rate of speed of the crank slows and then it estimates which cylinder did the misfire. the firing order is 1-8-4-3-6-5-7-2. you only are getting a random/ multiple cylinder misfire, if the computer was able to pinpoint that it really is 1 and 8 misfiring you should have gotten p0301 and p0308. also see how cylinder 1 and 8 are right next to each other, the misfire counters are just a best guess.

 

I hope you get it figured out, i know how frustrating misfires can be.

[pm gm]

have you cleaned the maf? i had a misfire problem the other week and after checking everything it ended up being a dirty maf. I think a valvetrain failure is not very likely but you never know

 

checked fuel pressure? also which codes is if showing? Are they saying cylinder X misfire or are you determining the misfires by viewing the misfire counters on a scan tool?

 

 

Yes.. I used a snapon scanner that shows current cylinder misfires.. This is how it looks.

 

 

MISFIRE _________ HISTORY

CYL 1____ 38 ____ 135643

CYL 2____ 0 _____ 21

CYL 3____ 0 _____ 335

CYL 4____ 0 _____ 14

CYL 5____ 0 _____ 60

CYL 6____ 0 _____ 54

CYL 7____ 0 _____ 0

CYL 8____ 1 _____ 3817

 

While the engine is running you only get misfires on #1 and #8 all the rest are ok. I checked the fuel pressure that was good and I also cleaned the maf. The truck starts right up no hard starts or anything it just has a slight miss at idle.

 

Engine codes were.. p0300, p0200

 

Im new to these motors but they seem to be alot easier to work on the gen 2 engines, so if you guys can tell me what to check next i can do it and report back my findings...

 

Thanks

Pernell

 

 

i see, well the p0200 code is probably whats causing the p0300. your probably going to need to get a hold of a wiring diagram and start checking continuity on the injector harness. also you could check and clean the pcm wiring harness connections.

 

Just an FYI: you have to remember that the misfire counters on a scan tool aren't very accurate. the computer detects a misfire when the rate of speed of the crank slows and then it estimates which cylinder did the misfire. the firing order is 1-8-4-3-6-5-7-2. you only are getting a random/ multiple cylinder misfire, if the computer was able to pinpoint that it really is 1 and 8 misfiring you should have gotten p0301 and p0308. also see how cylinder 1 and 8 are right next to each other, the misfire counters are just a best guess.

 

I hope you get it figured out, i know how frustrating misfires can be.

 

 

 

 

Ok, Do you know where I can get a wiring diagram off line? I will also check the pcm to. It is very fustrating I have had no problems with this truck up until now. The one problem I do have has no straight answer to it. I don't want to drive it until I figure out what it is...

 

Thanks for the help..

[Gregs]

have you cleaned the maf? i had a misfire problem the other week and after checking everything it ended up being a dirty maf. I think a valvetrain failure is not very likely but you never know

 

checked fuel pressure? also which codes is if showing? Are they saying cylinder X misfire or are you determining the misfires by viewing the misfire counters on a scan tool?

 

 

Yes.. I used a snapon scanner that shows current cylinder misfires.. This is how it looks.

 

 

MISFIRE _________ HISTORY

CYL 1____ 38 ____ 135643

CYL 2____ 0 _____ 21

CYL 3____ 0 _____ 335

CYL 4____ 0 _____ 14

CYL 5____ 0 _____ 60

CYL 6____ 0 _____ 54

CYL 7____ 0 _____ 0

CYL 8____ 1 _____ 3817

 

While the engine is running you only get misfires on #1 and #8 all the rest are ok. I checked the fuel pressure that was good and I also cleaned the maf. The truck starts right up no hard starts or anything it just has a slight miss at idle.

 

Engine codes were.. p0300, p0200

 

Im new to these motors but they seem to be alot easier to work on the gen 2 engines, so if you guys can tell me what to check next i can do it and report back my findings...

 

Thanks

Pernell

 

 

i see, well the p0200 code is probably whats causing the p0300. your probably going to need to get a hold of a wiring diagram and start checking continuity on the injector harness. also you could check and clean the pcm wiring harness connections.

 

Just an FYI: you have to remember that the misfire counters on a scan tool aren't very accurate. the computer detects a misfire when the rate of speed of the crank slows and then it estimates which cylinder did the misfire. the firing order is 1-8-4-3-6-5-7-2. you only are getting a random/ multiple cylinder misfire, if the computer was able to pinpoint that it really is 1 and 8 misfiring you should have gotten p0301 and p0308. also see how cylinder 1 and 8 are right next to each other, the misfire counters are just a best guess.

 

I hope you get it figured out, i know how frustrating misfires can be.

 

 

 

 

Ok, Do you know where I can get a wiring diagram off line? I will also check the pcm to. It is very fustrating I have had no problems with this truck up until now. The one problem I do have has no straight answer to it. I don't want to drive it until I figure out what it is...

 

Thanks for the help..

 

 

 

i'm not sure where to find a wiring diagram, if you have someone who has a subscription to alldata or something like it, that would probably be your best shot

[Carder09]

Just recently my buddy had the same problem, turned out the lifter had gone bad, looked like the roller seized and it rubbed on the cam causing chunks of metal to come off the roller, checked the cam lobes and they were all fine, bought a whole new set for the corresponding side and put all back together and it runs fine. Took it to the dealer when problem first showed up and they quoted him 4K to pull the heads off and take a look, Just to take a look and not fix the problem!! So he gave them the finger and fixed it himself for around 300-350 I think,