Missfire
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Joined: Jan 2007
Posts: 93
Likes: 0
From: Florida
Short version...
Front to rear 1357 driver's side. Front to rear 2468 passenger side.
Without knowing more about the mechanical condition or maintenance history these are the most common misfire causes:
Worn/misgapped spark plug
Leaking plug wire
(loose connection, burned, old)
Dirty injector
Bad coil
Oil fouling of spark plug
(worn piston rings, valve guides, valve stem seals)
Low compression
Worn/lifter cam lobe
Stuck valve
Broken/ bent push rod
Front to rear 1357 driver's side. Front to rear 2468 passenger side.
Without knowing more about the mechanical condition or maintenance history these are the most common misfire causes:
Worn/misgapped spark plug
Leaking plug wire
(loose connection, burned, old)
Dirty injector
Bad coil
Oil fouling of spark plug
(worn piston rings, valve guides, valve stem seals)
Low compression
Worn/lifter cam lobe
Stuck valve
Broken/ bent push rod
Burning Brakes
Joined: Feb 2006
Posts: 1,085
Likes: 3
From: Ottawa Ontario, Canada
#8 is the rearmost cylinder on the pass side.
I'm assuming you've read a code to determine the location of the miss?
All I can offer is that during my header install I didn't get one of the plug wires fully on, and about two weeks later I started getting a misfire that quickly got worse to the point the car would shake like crazy with high throttle/low revs. I popped the hood and could see the spark jumping THROUGH the boot to my header. I shut the car off (very important!
), spun the boot 180 degrees and pushed it on fully. Misfire gone, and it never came back.
The reason I'm telling you this is because even though the car was running like a smashed can of @$$holes I never got a single code and the SES light never came on.
A Saturn I had a long time ago had a plug wire fail (misfire with the same symptoms AND the SES light) and the dealership pulled the code and diagnosed it immediately (car was still under warranty and I was still in college). ?
Start by letting the car idle with the hood up in a very dark quiet place. Look/listen closely for a spark jumping from a plug wire to anything nearby (check all of them while you're there).
Based on my experience I'd be surprised if it was a bad wire, but you never know. Start with the easy stuff. If it's not a wire I'm not sure. Fouled plug(s), injector, coil pack? Hopefully others will offer more specific advice. Good luck.
I'm assuming you've read a code to determine the location of the miss?
All I can offer is that during my header install I didn't get one of the plug wires fully on, and about two weeks later I started getting a misfire that quickly got worse to the point the car would shake like crazy with high throttle/low revs. I popped the hood and could see the spark jumping THROUGH the boot to my header. I shut the car off (very important!
), spun the boot 180 degrees and pushed it on fully. Misfire gone, and it never came back.The reason I'm telling you this is because even though the car was running like a smashed can of @$$holes I never got a single code and the SES light never came on.
A Saturn I had a long time ago had a plug wire fail (misfire with the same symptoms AND the SES light) and the dealership pulled the code and diagnosed it immediately (car was still under warranty and I was still in college). ?
Start by letting the car idle with the hood up in a very dark quiet place. Look/listen closely for a spark jumping from a plug wire to anything nearby (check all of them while you're there).
Based on my experience I'd be surprised if it was a bad wire, but you never know. Start with the easy stuff. If it's not a wire I'm not sure. Fouled plug(s), injector, coil pack? Hopefully others will offer more specific advice. Good luck.
Tech Contributor
Joined: Aug 2008
Posts: 2,902
Likes: 21
From: Oak Hill Virginia
Short version...
Front to rear 1357 driver's side. Front to rear 2468 passenger side.
Without knowing more about the mechanical condition or maintenance history these are the most common misfire causes:
Worn/misgapped spark plug
Leaking plug wire
(loose connection, burned, old)
Dirty injector
Bad coil
Oil fouling of spark plug
(worn piston rings, valve guides, valve stem seals)
Low compression
Worn/lifter cam lobe
Stuck valve
Broken/ bent push rod
Front to rear 1357 driver's side. Front to rear 2468 passenger side.
Without knowing more about the mechanical condition or maintenance history these are the most common misfire causes:
Worn/misgapped spark plug
Leaking plug wire
(loose connection, burned, old)
Dirty injector
Bad coil
Oil fouling of spark plug
(worn piston rings, valve guides, valve stem seals)
Low compression
Worn/lifter cam lobe
Stuck valve
Broken/ bent push rod
How many miles on your current plugs and wires? Start by checking them... by far the most common cause.
