Spark plug gap

[southtj]

I just changed the plugs in my Jeep and was told to gap them at 35. When I took the old plugs out they were gapped at 50-60. They were the original plugs from the factory and were NGK brand. It seems to run fine but I thought I heard some pinging under load but it is hard to hear with the top down. So is 35 correct for an 04 6cyl?

 

[xt master]

I know on the 97 2.5l it is .035 gap.You can look at the sticker under the hood to find out the factory gap setting.

 

[SteelHeadz]

4.0L 6-Cylinder ZFR5N (NGK #) 0.77 mm - 0.90 mm (0.030 in. - 0.035 in.)

 

[southtj]

Thanks guys. I checked under the hood and it is .035. I guess they've been way off for the past 48,000 miles.

 

[jfrabat]

Actually, it depends on your ignition system; I use a Performance Distributor ignition system, and it lets you gap to .060" without issues (the bigger the gap, the better combustion you will have as long as the ignition ca handle the gap).

 

[Bounty__Hunter]

.035" is correct, chances are your old plugs were just worn to the point of having a larger gap. Check with Performance Distributors for a hotter ignition and you can run a wider gap. Mine are at .060" also.

 

[Crazy4diesels]

check out my earlier post about pinging and spark plugs... - John