Ve 3.0l sidi error code P0300 , any ideas??

[ozjet400]

Yes,

 

[ozjet400]

I just replaced the coils. New plugs. New 02 sensors ( all 4) cleaned the MAF with the correct cleaner. Checked the intake for carbon. Cleaned the throttle body out. Went over every single vacuum line. Even sprayed carb cleaner around every vacuum line and joint to find any vacuum leaks

Battery voltage over 13v when not running. 14.3 when idling

I hold the throttle to 2500- 3000 rpm while stopped In park. the P0300 code still appears .. the engine sounds great. No misfire

I am now getting a brake and abs fault light. While the car is not moving... and these faults don't come up on the scanner... just the P0300

Any advise welcome

 

[RiCeY]

Does your scan tool show a misfire graphic so you can see which cylinders are misfiring? You won't always feel misfire.

 

[ozjet400]

Hi..

It might be a dodgy alternator

Ive been just checking the voltage at the jump start points under the bonnet.

It can fluctuate between 12.5 to 15.2 v at idle

Seems to be erratic

 

[Danny-VE]

I'm having the same symptoms:
1. The princess highway in Adelaide has a steep descend in to the city and I usually run the engine brake so that I don't cook the brakes going down. After about 2 minutes I start getting check engine and the Stability Control OFF warning but it goes away after returning to normal driving conditions on the flat.
2. While sitting at the light the engine starts having a slight tremor and feels like it is skipping explosions but no CEL.
3. Fuel consumption seems to have increased a bit and also seems to loose some power.
4. When I start it from cold, it idles high much longer that usual before returning to normal idling RPMs

Had it in the service and they, supposedly, replaced my spark plugs, cleaned the valves and check the compression, etc... but nothing.

I am now suspecting either a vacuum leak, the EGR valve or the coils. I posted a question on the forum to find out where the EGR valve is and maybe obtain a manual so that I can take it out...

Any other updates, have you located you cause.?

EDIT: Forgot the car... 2011 Commodore VE Series 2 Omega, 3.0 V6 SIDI.
EDIT 2: Forgot the ODB Code... P0300 and nothing else.

Thank you,
Daniel

 

[VTS5]

Just replace the coils.. Cause 9 out 10 times coil/s is the culprit.

 

[VS_Pete]

I sent OP a PM hope he replies.

 

[Kevin Galloway]

Hi,sorry to tag along but have same P0300 fault. Just did an engine change and getting misfire code on cyl 2,4,6. Have noticed no check engine alarm on initial start up, it comes up after idling for 10 to 20 secs.
I'm not sure what alarms were on before the engine change as I didn't drive it.
Can i swap sensors on cats to check if one is faulty?

 

[syked]

Hi,sorry to tag along but have same P0300 fault. Just did an engine change and getting misfire code on cyl 2,4,6. Have noticed no check engine alarm on initial start up, it comes up after idling for 10 to 20 secs.
I'm not sure what alarms were on before the engine change as I didn't drive it.
Can i swap sensors on cats to check if one is faulty?

If you have the misfires on 1 bank it might be something like a harness which connects the coils or injectors.

But have you checked / replaced all spark plugs

You can also change the coils from one side to the other side of and see if the fault follows the coils or the stays on the same bank.

Misfires aren't really related to post cat O2 sensors so no point looking there.

 

[Kevin Galloway]

Thanks syked, I got my son to have a look to see if he could find something and he found that I had left a small earth wire that bolts onto the head, it appeared to be bolted but it was only resting against the head.
Car runs fine now.