What Causes a New Spark Plug to Fail

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skullandbiscuits

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 Somerset
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My E85 N52B52A let me down for the first time last week, after changing the spark plugs and driving it for 100miles everything was fine until it started to misfire.

I have scanned and diagnosed it to be cylinder 4 with the issue.

I have tried the following:-

Reseated the spark plug
Reseated the coil
Swapped coils with cylinder 1

I then put the old spark plug back in and the issue was resolved for 5 minutes, and it started misfiring again on cylinder 4.

This is the new spark plug after 100miles.

I can only think of a failing injector or worse a failing piston ring.

TIA
 

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I’m not convinced it’s that, as the I’ve put the old spark plug back in and it’s still misfiring on the cylinder.

No harm in removing all the plugs and checking the gaps
 
Have you swapped the spark plugs around. You mentioned the coils, but not if you had tried that. It does read like the problem is sticking with number 4 Cylinder. In which case fueling is the next place to start.
 
I’m going to put all the old spark plugs back in and see how it’s running.

TBH I’ve never gapped spark plugs, I’ve always installed them.

The new Bosch spark plugs that I ordered are the same part numbers as the ones that came out.

Thanks all
 
It's worth checking the earths across all coils. Coils need a really good earth as they produce high voltages.
When I changed the plugs on mine it was fine for a while then started getting all 'lumpy' with misfires everywhere. One of the earthing strap bolts had come loose as I obviously didn't tighten it up enough when putting it back.

Also check the electrode connector inside the offending coil for crud and that it clamps tight onto the plug.
 
Nice feedback guys, really appreciated.

I was drunk at a party and was trying to shout “Skull and Cross Bones” but “Skull and Biscuits” got splurted out instead.

So it’s stuck with me 🤣
 
This poxy issue denied me taking the Z4 to the Nurburgring, it started misfiring on the A303 enroute.

And it’s currently blocking my hydraulic steering conversion.
 
skullandbiscuits said:
This poxy issue denied me taking the Z4 to the Nurburgring, it started misfiring on the A303 enroute.
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They have a habit of going wrong just to annoy you, don't they?
I spent all morning the other week changing some bits in the engine bay after waiting two weeks for them to arrive. Got it all done, gave the car a wipe over and went to take it somewhere pretty to take some photos. 300 yards from my house all the dash lights came on!
Had to go back and diagnose that issue, then order more parts from the supplier. Luckily it was only a wheel sensor, so I just put tape over the lights as they are annoying!
I just don't like driving a car with ANY faults. Probably picked the wrong car, then!! :p
 
skullandbiscuits said:
Nice feedback guys, really appreciated.

I was drunk at a party and was trying to shout “Skull and Cross Bones” but “Skull and Biscuits” got splurted out instead.

So it’s stuck with me 🤣
Click to expand...

Bollocks I’m not buying that shite…! 🤨

There’s something much more exotic or sexually embarrassing than that load of old cobblers…🫵😆
 
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plugs provided by Amazon not another seller on that site are actually likely to be real. My NSX tech who is very cautious (and japanese) buys them from Amazon. EBay of course is likely to be rubbish
 
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