Whole bank misfire, good spark

[2007gmc1500]

hey guy so a few weeks ago i developed a misfire on my 05 sierra with the 4.8 it would come and go truck has no codes one day it died and would not start changed plugs and wires plugs and it started up, but bank 1 is still dead they have good spark the plugs are wet with fuel. short and long term fuel trims on both banks are pegged at -30% did a compression test all are within 10% of eachother and have good comp i did develop a p0134 02 sensor bank 1 sensor 1 low activity could that cause a whole bank miss? scanner shows it isnt switching

[richard wysong]

do you have power to the injectors? check with noid light or test light. they should have power and use the ground as the trigger I believe, all controlled by the PCM. start with the basics , check fuses and wiring if no pulse before pinning the PCM

[2007gmc1500]

fixed it the bad plugs i had causing the miss in the first place caused a ton of gas in oil. changed the oil and it runs smooth again!

[richard wysong]

attaboy!

[swathdiver]

12 hours ago, 2007gmc1500 said:

fixed it the bad plugs i had causing the miss in the first place caused a ton of gas in oil. changed the oil and it runs smooth again!

Keep an eye on the cats now, that issue could have shortened the life of the one on that bank.  Just something to keep in mind.

[2007gmc1500]

1 hour ago, swathdiver said:

Keep an eye on the cats now, that issue could have shortened the life of the one on that bank.  Just something to keep in mind.

im thinking it did it threw the p0420 low efficiency code it did go away after i drove awhile though

[swathdiver]

1 hour ago, 2007gmc1500 said:

im thinking it did it threw the p0420 low efficiency code it did go away after i drove awhile though

 

Yep, happened to mine too.  Cats failed about 10K miles after AFM did.  Stick with USA made cats, not no-name Chicom stuff, it barely lasts a year.

 

I put on Magnaflow cats and y-pipe.

[dna9656]

I was sure it was the injectors bu with gas in the oil no, it's not the injectors.

Way to go Richard!

[2007gmc1500]

well i think my engine is about to bite the dust. finally got aorund to swapping in a new oil pressure sensor the old one read 80psi always and found the oil pressure is about 5 psi hot idle and 20 while cruising i did another oil change and opened the filter and found lots of small metal flakes (they are magnetic) no valvetrain or bottom end noise though

[richard wysong]

thats not good, probably some kind of bearing material. could be cam bearing where you have no noise. when they rebuilt my engine they didn't mike the crank and its had ****** for op ever since I put it in, They said pull it out and they would fix it. I asked them if they  thought it was held in with zippers so its been like that for 70k miles now. I run Castrol 20-50w and it has much better pressure than anything else. when the pressure starts to drop off I know it's time to change it

[Brenden Burnham]

On 2/8/2022 at 5:14 PM, richard wysong said:

thats not good, probably some kind of bearing material. could be cam bearing where you have no noise. when they rebuilt my engine they didn't mike the crank and its had ****** for op ever since I put it in, They said pull it out and they would fix it. I asked them if they  thought it was held in with zippers so its been like that for 70k miles now. I run Castrol 20-50w and it has much better pressure than anything else. when the pressure starts to drop off I know it's time to change it

"I asked them if they  thought it was held in with zippers"

LMFAO at that one

[swathdiver]

On 2/8/2022 at 1:15 PM, 2007gmc1500 said:

well i think my engine is about to bite the dust. finally got aorund to swapping in a new oil pressure sensor the old one read 80psi always and found the oil pressure is about 5 psi hot idle and 20 while cruising i did another oil change and opened the filter and found lots of small metal flakes (they are magnetic) no valvetrain or bottom end noise though

How is it going with the motor?

[2007gmc1500]

On 2/17/2022 at 6:24 PM, swathdiver said:

How is it going with the motor?

It seems to be running good lots of metal flake in the oil though. Think when June comes and the snow melts I might just swap in a 5.3 from a junkyard

[swathdiver]

1 minute ago, 2007gmc1500 said:

It seems to be running good lots of metal flake in the oil though. Think when June comes and the snow melts I might just swap in a 5.3 from a junkyard

 

Did you consider sending out an oil sample to Blackstone Labs to find out where the metal flakes are from?