Hey guys

On my 99 GS400, there was a random misfire in cylinder 6 and just this morning my brother and I changed the spark plugs to brand new NGK Iridium IX spark plugs. We took the car out for a drive to see if it was working and then we heard a sound coming from the engine, we pulled over and the car died.

My brother just tried to remove the spark plug in cylinder 6 and it was seized in there. A large chunk of the spark plug is missing: (sorry for the very large pics)




Did this ever happen to anyone?

 

dude your motor is toast

 

holy that sucks. i dont know how yo'll be able to pull it

 

Looks like you over tightened them a lot

 

Spark plugs were not torqued, only hand tightened with a rachet.

 

Can't say I've ever seen that before. Best of luck to you.

 

Can there be such a thing as a faulty plug exploding?? Lawsuit for new engine??

 

Thanks. I'll be taking the car to my mechanic on Wednesday.

I am going to call NGK's customer service tomorrow morning and file a claim. I've been using NGK Iridium spark plugs for years and this is the first time that it blew up.

 

Coil pack issue?

 

I don't think so. I swapped the coil pack from the misfiring cylinder to another cylinder and the spark plug in that one looked fine. I also tried to install the old spark plug in the same cylinder but at a point, the electrodes on the spark plug got bent inwards meaning that the piston is possibly higher up than what it should be.

 

Could it be you guys installed a wrong spark plug in that cylinder ? Wow never seen that before

 

Ouch. Time to upgrade... 430. =]

 

Nope, checked the spark plugs to make sure they were the same type and correct for the car.

or an LS1

 

Almost looks like something to do with timing and maybe a cylinder head might of hit it

 

Looks like the motor dropped a valve or sucked something through the intake.. I know its a pretty common issue in some nissan motors that have intermediary 'butterfly valves' in the intake manifold to have the bolts come loose and suck through the motor causing similar damage although usually not quite as extreme..


At any rate that motor is most likely toast.