Accelerating - POP! - dash lights up, running rough, shifting bad, etc.

[AJMBLAZER]

This morning while heading to work I was accelerating onto the highway and at about 50mph I feel/hear a POP in front of me and several lights come on. Engine is misfiring and running rough. SES light, service parking brake light, traction control off light turn on and the transmission is shifting hard. I coast off the on ramp, turn it off, and look it over. No rod sticking through the block or pan. No sign of a head gasket. Seems to be correct oil pressure when running.

F&$@%##}#%}} I just paid it off
117,****** miles. Oil changed every 5,000 with synthetic and mostly highway miles.

Call out of work and limp it home.
I have an ancient scan tool and it shows P0303 cylinder 3 misfire. Reset the codes.

Swap the coil to cylinder 1 and put a new ACDelco plug and wire on cylinder 3. Was planning on doing plugs and wires this coming weekend ironically.

Runs better but not right. Lights come back on. Now the scan tool shows P0303 and P0500 which is the vehicle speed sensor.

WTH?
It wasn’t moving this time. Where’d the P0500 code come from?

Going to try putting a new coil on 3 and putting the cylinder 1 pack back on 1.

Would love some thoughts and hell, prayers.

 

[Blue85]

All of that stuff coming on at once seems like something temporarily took down the CAN bus. The seemingly unrelated issues could also point to a broken ground or something like that. It's worth checking the fuses since that's easy, but I would be interested in a compression/leakdown test on #3 and maybe others. A wild guess would be that something went wrong with the DoD control and it's not able to open or close both valves on that cylinder. Any chance you've had a rodent munching wires?

 

[AJMBLAZER]

No rodents that i’ve seen any signs of. It lives in my attached suburban garage when it’s not driven.

Video of the noise it’s making:
View attachment IMG_5057.mov
Makes a SNAP/POP sound on start up then settles to this.

 

[Blue85]

Do you think it's more of a 1x sound (rotating assembly) or 1/2 engine speed sound (valvetrain)?

 

[Wes Harden]

Many times now when an engine misfire code or ign code the computer disables the traction control lamp and abs. Not a can bus issue.

Listen to the valve cover on #3 might have a busted valve spring

 

[Blue85]

Many times now when an engine misfire code or ign code the computer disables the traction control lamp and abs.

Sure, but what does it have to do with the parking brake? I had a Buick that lit 3 lamps on the dash when it lost signal from a wheel speed sensor.

 

[Wes Harden]

Abs red is same as p brake

 

[Blue85]

Does it pop like this one?

Cliffs Notes: it goes rap, rap, rap, POP. On teardown, the issue was a stuck AFM lifter. The roller became stuck and was dragging on the cam lobe.

 

[AJMBLAZER]

It’s off to a shop. I made no headway swapping ignition parts.

First shop had CRAZY things to say. Second said “send it over and we’ll look at it. “

Oooof. I’m sick.