Missfire cyl 2 4 6, loss of power, stalling when hot

[wetherow]

Hey guys, I have a 2011 Series II sv6 LLT SIDI 3.6L commodore. it's been looked after but has recently developed a significant missfire.

prior to the missfire it had been throwing catalytic converter codes for bank 1 and 2 regularly but never had any issues for almost a year.

fuelled the car up at a different petrol station than usual then the miss fire started. it has codes P0300 P0302 P0304 P0306 and the check engine light flashed when accelerating and is super rough. when starting the car from cold it is OK and idles ok with slight vibration. after it's reached temp and driving around the block it missfires hard and stalls on low revs or slow speed like stopping at an intersection. when trying to start it again it struggles to turn over and sometimes won't turn over like the battery is flat but the battery is fine.

I have replaced the coils and plugs a year ago. I took the air intake off, throttle body, and manifold and found a bit of oil in the big plastic tube coming from the throttle body to the air filter (not sure if that means anything). I've looked at the cams and chains they seem ok, couldn't see any broken valve springs. I have taken the timing chains off and am going to replace them anyway as I thought it might be that. I'm not sure if it is now, any other ideas?

 

[cobbycob]

I’ve come across this issue before on a VZ same codes and same faults, it ended up being solder joins on the ecu coming unstuck when the heat finally soaked into it, if you want to confirm the fault, boil your kettle and poor hot water onto the ecu while it’s cold and see if it starts faulting

 

[blackvxss]

do a comprssion test

 

[wetherow]

so I've replaced the timing chain and reassembled the engine, all went well but now after reconnecting the battery the red security icon on the dash is on and the car won't start. keys don't work and no other light is on the dash. any ideas, I have tried all tips and tricks and have checked all cables they are ok.

 

[lout]

try turning ignition to reds
then press lock /unlock on remote
try turning ignition to reds, then off
then press lock /unlock on remote

 

[krusing]

so I've replaced the timing chain and reassembled the engine, all went well but now after reconnecting the battery the red security icon on the dash is on and the car won't start. keys don't work and no other light is on the dash. any ideas, I have tried all tips and tricks and have checked all cables they are ok.

The coil and injector plug could be an issue, as it’s in a Bugger of position.

 

[krusing]

Hey guys, I have a 2011 Series II sv6 LLT SIDI 3.6L commodore. it's been looked after but has recently developed a significant missfire.

prior to the missfire it had been throwing catalytic converter codes for bank 1 and 2 regularly but never had any issues for almost a year.

fuelled the car up at a different petrol station than usual then the miss fire started. it has codes P0300 P0302 P0304 P0306 and the check engine light flashed when accelerating and is super rough. when starting the car from cold it is OK and idles ok with slight vibration. after it's reached temp and driving around the block it missfires hard and stalls on low revs or slow speed like stopping at an intersection. when trying to start it again it struggles to turn over and sometimes won't turn over like the battery is flat but the battery is fine.

I have replaced the coils and plugs a year ago. I took the air intake off, throttle body, and manifold and found a bit of oil in the big plastic tube coming from the throttle body to the air filter (not sure if that means anything). I've looked at the cams and chains they seem ok, couldn't see any broken valve springs. I have taken the timing chains off and am going to replace them anyway as I thought it might be that. I'm not sure if it is now, any other ideas?

What model engine is it ?
K/s ?

 

[Fu Manchu]

It’s isolated to one bank.

 

[krusing]

It’s isolated to one bank.

Yes, I thought the same thing,
Possibly a ground connection, or ground wire in the loom,
Job for a good Multimeter !

And may have to back probe it to the ECU via the other connectors.

 

[wetherow]

What model engine is it ?
K/s ?

it's a 2011 LLT SIDI petrol. 219k km