abundigas

Hate to bring back a dead thread, I have an 08 JK 4 door x 6 spd with 40k on it, it just started pinging. I have determined that it goes away 100% almost instantly if I fill up with 93 octane, If i run 89 I very rarly get a ping, but if i use 87 I start pinging fairly consistantly.

If it is a Knock sensor, I think based on mileage I may be out of luck warrenty wise, I have not read the power train warrenty but I would not think it includes electronic sensors. Any thoughts?

I was thinking of a new set of plugs. any recomendations would be welcome.

The only mods I have done are the K&N filter, and I have P255-70-R18 for tires, and I did have the Speedo recalibrated.

buenhec

So did anyone find a real solution to the pinging?
I have a 2010 3.8 JK. Im running 35s on 4:88s.
My engine used to ping between 2-3k Rpm same as all of you.
I rebuilt the engine, changed EGK, knock sensor, and all the other sensors I could find.
Today, I replaced spark plugs with NGK Iridium plugs. It still pinged. I just removed the Hypertech tuning and replaced it with factory tuning and it pings even more. I have tuned it to 87 and 93 octane. Still pings.
I am pretty frustrated. Any suggestions?

rob_engineer

When my Ford Explorer pinged it was due to a leaky intake manifold gasket. Running 93 octane made it go away.

Mr.T

I tuned the spark advance tables and a few other items with the HP Tuners program. The factory timing is just too optimistic about fuel quality and perfectly clean combustion chambers. It's not a quick process, and it's not a "canned" tune, but it really does the trick. This is a pretty advanced way to go and it's best if you've got some background, but it's a whole lot easier than adjusting carbs and re-curving distributors back in the old days.

Mine is retarded ~3 degrees at the RPM's and manifold pressures most prone to spark knock. The basic process is log data while driving (knock retard, spark timing, manifold pressure, etc.) then change the relevant spark table, and repeat as necessary. The sensing of crank position is only so accurate from engine to engine, just like timing marks in the old days -- This essentially corrects for that, as well as mitigating all the other variables that cause spark knock.

If you go this route I'd be happy to send you my tune file which can be used for reference, compare, copy, paste...

Machoo

My solution was to add the highest tier gas from the best stations. Like Shell or Chevron. This was at my mechanics suggestion and it works. He told me to avoid the lower tier gas and crap stations. Arco being the worst. It is frustrating having to fill up with the most expensive gas every time but the ping does go away. If I use 87 once it comes back. Very annoying.

My mechanic doesn't seem to think there is anything to do about it. Mine is still under warranty and he doesn't hesitate to take warranty work so I know he is being honest about it. I have the 3.8 for reference.

buenhec

Thanks for the feedback and the PM's. The feedback really helped. I have finally resolved this annoying and persistent issue. I used shell 91 octane and added an octane booster. It took most of the pinging away. I then tried a Diablo and a Hypertech tuner and used and the 89 tunes. I got pinging with the 91 tunes. Both tuners worked the same. I'm guessing low quality of the fuels in my area. I will try some other gas stations using 91 fuel without adding a booster. Thanks again!