shadybiz11

Ok I attempted to change the plugs on my 2002 mustang. I put in NGK TR6's gapped at .035. The car is running worse than it was before I did the change. The COPs boots looked really good. everything unclicked good, and went back on well.

But unlike plugs & wires, I couldn't tell when the COPS would slide on the plugs. Anyway, the car runs like poop now. Any ideas?

Two of the plugs that were in the car had oil around the plugs, What caused that?

Stevo86

.035 is too small they should be gapped at .045-.052 so that is issue one. You probably didn't get a connector back on or the boot all the way down either and that is what is causing your new mis-fire.

As far as the oil goes, you have a leaky valve cover gasket.

shadybiz11

Thanks Stevo. .035 is what a local engine tuner told me, but the engine feels extrememly tight/bound up. Tonight I'm going to check and see what the old plugs were gapped at.

kurtis_garcia

Does your check engine come on at all..I just replaced all my plugs and 2 coils due to a guy detailing my motor he didn't do it correctly and i had water all in the cylinders so it faulted them out......but my car was running just like your talking bout i went with bosch 4+ titanium and don't have to worry about gapping them....it also comes with a 5 year warranty on it..not sure about the ngk plugs don't think they got a warranty but for the bosch at 6 buks a plug couldn't beat having that 5 year warranty even though they cost a lil more.....like shady said yeh gasket on it is bad.......hope your car gets to running better i know i was frustrated all weekend because of it running like chit i feel your hurt bro haha

cliffyk

Get a set of single platinum plugs from Motorcraft or Champion, and ditch the nickel/chrome electrode TR6 plugs. Conventional electrode plugs like the TR6s were needed years ago in moderate boost/higher compression applications, before the EDIS and COP ignition systems were developed, however they are not needed with any but the highest combustion chamber pressures now--and certainly not needed or even desirable when running n/a.

I made 262/305 rwHP/lbft on my '03 with modest bolt-ons, 24 lb/h injectors, a tweaked tune and Champion stk #3401 single platinum plugs. That's all you need and they'll last 80k to 100k miles to boot.

You may want to remove and reinstall the COPs, though I have never gotten one installed incorrectly. They don't give you that comfortable "snapped on" feedback, but they will seat fine with little effort...

02GTowner

My vote is for motorcraft as well.