Cylinder 7 misfire

dj_jace

dj_jace

Active LVC Member
Joined
Jan 16, 2014
Messages
159
Reaction score
4
Location
Winchester
So car started running rough and now im getting a misfire on cylinder 7 code... id say its the coil pack... question is can I make it home (30 min drive) with it sputtering like this or should I park it and go buy a coil pack and change it here... normally id just change it here but its like 5 degrees outside right now... thoughts?
 
There is no code that "says it is the coil pack."
There is a general misfire code that says the PCM believes that cylinder 7 is misfiring, and there is a code that says there is a problem with the primary circuit for coil 7 (could be the coil, the connector, the wiring, or the PCM). Also note that the LS uses COPs, not coil packs.

COP = Coil On Plug - A single coil that fires a single plug, often with no primary (spark plug) wire.
Coil Pack = A package of two or three coils that fire four or six plugs, with connections to the spark plugs made by primary (spark plug) wires.

Anyway, the short answer is that you may damage your catalytic converter. You could unplug the #7 fuel injector to eliminate this possibility, but the fuel injector connectors are really easy to damage.
 
By now the question is moot since we assume you made it home.

Usually if a coil fails it is intermittant to start and gradually gets worse. You can drive for hundreds of miles although most of us, including me would NOT recommend it. But you do not need to slam on the brakes and bail out of the car right that moment.

A failed coil is like any old fashioned spark misfire... the engine will run rough, you will have less power, you will make more smog and with modern emission systems you may eventually clog the catalytic converter and set various engine codes.

Just get yourself a new one at your earlierst convenience. That hardest part of the job is getting at a couple of the screws on either coil cover, just no room for fat hands.

I have gotten good at replacing coils, takes me maybe 15 minutes if I take it easy. Used to be a couple hours since I didn't know which tools worked best.

As proof of running on a failed coil, look at aboout page 95 of the thread "What did you do to your LS Today?". I totally blew out #7(a coincidence?) plug, destroyed(blown out sideways) coil #7 , about as failed as a coil gets, and chuffed home 6 miles before I could effect repairs.

Right now while I wait for a new coil, I am using a "Failed" coil That I removed last summer and had thrown in my junk pile. After about 200 miles on this "failed" coil, no stumbles, no engine codes etc. I know this particular "failed" coil is heat sensitive. Almost all my coil failures over the years have been in the summer.

Good Luck,

Jim Henderson
 
Im at work actually so not home yet... today is the first sign that it has gone bad. I had another one go bad over the summer... easy to fix I just would rather do kt at home in the garage than outside in the parking lot at work...
 
I don't blame you there. You don't want to hear this, but you need to replace the spark plug too.
 
if you buy quality, they'll work. people have been running aftermarket cats
for years with little issue.

if you buy the cheapest cat on ebay, then yes, you may have a problem down
the road.
 
I bought the magnaflow ones, which were not cheap and of good quality and even they caused several head-aches. The universal ones are just garbage. AFAIK the only three good ones that are useable are: Walker, Magnaflow, and Eastern. And even with those three, several issues have been reported. YMMV
 
elephantrider said:
if you buy quality, they'll work. people have been running aftermarket cats
for years with little issue.

if you buy the cheapest cat on ebay, then yes, you may have a problem down
the road.
Click to expand...
not necessarily, there have been more than a couple of people who have had problems with "quality" aftermarket cats on here. sure they may be function well enough and doing their job, but they may just be outside of what the PCM wants to see and will throw a code.




OP: lets put it this way, sure you can drive with a misfire. how far, don't know, but every misfire causes some damage and who knows how much is too much... (actually the correct answer is any, is too much)
 
Thanks for the replies everyone... I dont want to risk any damage so im going leave it parked at work... going to layer up and change it there tomorrow afternoon... I would love to change all 8 and plugs but dont have that kind of cash at the moment... so ill just do the 1 cop and I have an extra unused plug at home...
 
i've only used kooks high flow cats, and we've never had issue. have used
the walker ones a few times on some odd jobs, and had no issues.

dj - i have a set of plugs i'll send you if you cover shipping. i bought a set
and there was already an extra set under the seat for some reason.

lemme know.
 
The problem is probably not with the cats, it's with the LS. The LS is very picky about what it will accept and won't accept parts-wise. Stuff that would work 99% of the time on every other car will work 1% of the time on an LS. Research aftermarket alternators just to get an idea!
 
i get it - the downstream o2 will see too much scrub on the exhaust and throw an
inefficiency code.

i've seen on here about the finicky alternators, too. now i got nothing on that other
than wtf, over.
 
well, what was so strange about it is that he just had the cop and plugs replaced
at a mechanic shop that the 1st owner used, along with the dealership, so i have
a fresh set in engine already. if i can pay something forward with helping him out,
i will - i need some good karma these days, i have had one BEOTCH of a year.
 
Yeah, perhaps we differ, paying forward is a lot of fun on a coffee through a drive through or something but a brand new set of OEM coils runs well into the 400's

They have a for-sale section on this forum as well but that DJ is a swell lad I'm sure, anyone that wants to change out a coil & plug on #7 in this weather deserves a gift alright!

Me, I'd already be home with it. 30min is peanuts, don't get anywhere in life if you don't take a chance now and then. calling a flat bed would be best choice of course.
 
BigRigLS said:
Yeah, perhaps we differ, paying forward is a lot of fun on a coffee through a drive through or something but a brand new set of OEM coils runs well into the 400's....
Click to expand...

I'm confused again. I thought he was talking about spark plugs. (Still, a $40 to $80 value, nothing to sneeze at.)
 
joegr said:
I'm confused again. I thought he was talking about spark plugs. (Still, a $40 to $80 value, nothing to sneeze at.)
Click to expand...

Time to put the glue away!

EDIT: left the cap of the markers again :runaway:
 
You must log in or register to reply here.

Members online

No members online now.
Total: 481 (members: 0, guests: 481)
Back
Top