Misfire

[Rubberman]

2001 grand am 2.4l twin cam engine. Random misfire on cylinder 4

Changed plugs, still misfire
Changed plug 4, still misfire
Swapped coils , still misfire
Changed the rubber plug boot , still misfire

Only thing else to try is the plastic housing cover. I did replace that a couple years ago. Visually it looks fine.

I’m using live data on my scanner to see the misfires. Avd they are random. Meaning it will misfire then run fine then the misfires start. Repeat.

Thoughts, ideas?

 

[melsg5]

Check other causes here

OBD-II Trouble Code: P0304 Cylinder 4 Four Misfire Detected

 

[Rubberman]

It ended up being the plastic ignition cover

 

[LokiGrandAm]

2001 grand am 2.4l twin cam engine. Random misfire on cylinder 4

Changed plugs, still misfire
Changed plug 4, still misfire
Swapped coils , still misfire
Changed the rubber plug boot , still misfire

Only thing else to try is the plastic housing cover. I did replace that a couple years ago. Visually it looks fine.

I’m using live data on my scanner to see the misfires. Avd they are random. Meaning it will misfire then run fine then the misfires start. Repeat.

Thoughts, ideas?

I'd pull the plug and check the valve condition, you'll need an inspection camera, but they've gotten decently cheap these days. I'd recommend one with a side camera so you don't accidentally drop a mirror attachment into the cylinder, I was always afraid of doing that.

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[melsg5]

I'd pull the plug and check the valve condition, you'll need an inspection camera, but they've gotten decently cheap these days. I'd recommend one with a side camera so you don't accidentally drop a mirror attachment into the cylinder, I was always afraid of doing that.

Did you read post 3?

 

[Rubberman]

I'd pull the plug and check the valve condition, you'll need an inspection camera, but they've gotten decently cheap these days. I'd recommend one with a side camera so you don't accidentally drop a mirror attachment into the cylinder, I was always afraid of doing that.

I mentioned above it was the plastic ignition cover. Replaced that and it’s been running fine