Ok so i did some usual maintenance today on my OZ. It was due for an oil change and i hadnt done the plugs before (since i bought it with 45K miles already on it)

I did some reading on here about which plugs to use and found most said the NGK OEM replacements were fine. Got the plugs, checked the gap ( .040 ) pulled the old ones (which i checked and found to be .050 ) put anti-seize on the threads and some plug grease on the tops and re-installed.

Car starts up nice and smooth, idles great and accelerates smoothly. However i found today while driving that it seems to break up a bit at the top end in higher RPM. Why would this happen ? This was literly the first time i took the car out after changing the plugs. Are plugs something that need a break in period ? Any suggestions would be appreciated!

 

Spark plugs do not need any brake in period. What kind of breaking up are you talking about? Maybe you are misfiring or something? Triple double check all the wires, connections, and gaps. What kind of plugs do you have? Did you buy new ones and replaced the old ones? Or just regapped the old ones?

 

I bought brand new NGK plugs, they were properly gapped at .040 (i checked) Ok i didnt think they needed a break in period. Ill double check the wires, but i think they are all fine. Its not so much of a bad mis-fire, its more just that it doesnt sound/feel smooth in the high RPM range now. Like something isnt firing just quite right. Im talking like maybe within 500 - 750 rpm of redline.

 

Maybe your car was used to the old bad-gap plugs.

Reset the ECU and let it relearn, perhaps?

 

Dielectric grease dielectric grease dielectric grease. Don't ever change plugs without it. You can have the baddest *** plugs and wires but if you don't grease them you never get full spark from the coil though the wire to the plug.

 

used dielectric grease, always do. Can you use too much ? Maybe i over did it ? Ill try re-setting the Ecu, good idea.

 

Doesn't the ecu reset when you unhook your battery and aren't you supposed to unhook your battery when changing spark plugs? I do at least...

 

I don't suppose there is a detailed how to on this is ther? The one I found was a little vague to me! :et me know how it goes man! I still need to get the tools and everything to do it! I have the plugs, but i still need to get new wires. What else do I need to be able to do this myself?

 

No there is absolutely no reason to disconnect the battery when doing plugs. And I just did my plugs the other day and no probs.... I didn't use any grease either.

You might try taking the plugs back out and rechecking the gaps. It is very easy to bump the plugs as you are sticking them back in. And it only takes like.... not even 5 minutes to take take them back out, recheck gap, and put them back in. Also, make sure when you are putting the plug boots into the holes that you listen or feel for the click of the boot snapping onto the plugs. You can't really hear it with the coil pack boots but you can stick your fingers under the coil packs and make sure the boot is good and sealed.

 

i have the same issue. it breaks up at the same point yours does. ive tried different gaps and im still stumped

 

you could check your wires. run the car, hold on to one of the sparkplug wires and then touch a part of the engine bay, lol. that's how i found out there was a cut somewhere in the shielding.

you could check your ground wires too. rusted or loose maybe? one is that dinky ground wire next to the camshaft position sensor on the driverside of the engine. it apparently doesn't ground to the engine bay. the other one is next to the driver side strut where a bunch of ground wires seem to be bolted to the engine bay. there's also a dinky ground wire from the engine to the engine bay on the passenger side by the timing belt cover.