blew coil 4th coil pack. NEED some input

[G4nismo]

yeh, 4rth coil pack for the same cylinder blew this morning.before any one asks, i checked ALL 3 of the wires for the coil plug and even compared the resistance readings and what not to other cylinders. everything is fine. checked the power supply, the ground circuit, and the output signal circuit (basically continuity b/t ecu and coil harness)

couple people suggested maybe its the spark plug. replaced that, car ran fine for about 2 weeks till this morning.

now i'm out of ideas. need some help

[jltibbs]

Get a new coil, put it on cylinder three and use the coil from cylinder three on cylinder one. Give that a shot and see what happens. If it goes bad on cylinder one again, then its not the coil. If it goes bad on three, then buy your coils from someone else.

[G4nismo]

Get a new coil, put it on cylinder three and use the coil from cylinder three on cylinder one. Give that a shot and see what happens. If it goes bad on cylinder one again, then its not the coil. If it goes bad on three, then buy your coils from someone else.

its cylinder #2 thats having the issue by the way

firewall1 3 52 4 6front

i'll try that out though.

[NutriaforBreakfast]

Compare the spark plug electrode of the blown coil cylinder to theother plugs of the other cylinder and see if there is a difference.Chiltons has a good color picture of plugs and potential problems youmight see and use to "read " the cylinder issue. Have you also triedchecking the compression of all the cylinders?

[G4nismo]

Compare the spark plug electrode of the blown coil cylinder to theother plugs of the other cylinder and see if there is a difference.Chiltons has a good color picture of plugs and potential problems youmight see and use to "read " the cylinder issue. Have you also triedchecking the compression of all the cylinders?

i installed new spark plugs for all the cylinders though.

and no b/c i don't have a compression gauge.

[newbissan-tech]

it's not the coils there is a bulletin @ the dealer where there's a problem with the main engine harness and they usually have to replace the engine harness, and it's not cheap either! there is a breakage in the harness that causes missfires and coils to go bad!

[G4nismo]

it's not the coils there is a bulletin @ the dealer where there's a problem with the main engine harness and they usually have to replace the engine harness, and it's not cheap either! there is a breakage in the harness that causes missfires and coils to go bad!

well i was starting to think maybe the cheap aftermarket coils just suck so i went and bought a nissan coil. but your saying there not the coils???

what do you mean the main engine harness? the big loom of wires all wrapped together, the one you can see right in front of you when you pop the hood? that doesn't make sense...

[NJ 666]

Like someone elsesaid swap 2 of the coils to determine if the coil is failing again. I've seen plenty of aftermarket coils fail after a short time.

The harness doesn't always have to be replaced it can sometimes be repaired. sometimes the shielded wires can be repaired but it is a little sketchy.

Check out ITB98-006b

[newbissan-tech]

dude i work at the dealer! i would be about 99.99999% sure its the engine harness! they have an internal breakage or short! could even take out the ecm!! but good luck man!

[NutriaforBreakfast]

Is there any oil on the coil pack? Maybe the rubber seals on thevalve covers are worn out