I have this off and on issue with my '10 jk unlimited 6 spd...when there is a load on the engine (starting from a stop) or going up a hill and lugging it a bit, i get what sounds like piston slapping or maybe its pinging? im not sure...does anyone else have this issue and how can i solve it.

 

Had same type of sound and change gas stations and upped the grade of gas and haven't herd it in about a month.

 

you running 89 or 91?

 

More than likely your valves are carboned up. Try adding some seafoam cleaner and run 2 tanks with it. Then go to a dealership and pick up a can of Chrysler combustion chamber cleaner. Spray contents directly into the throttle body and shut off motor and allow to sit a few hours. Re-start and change your oil. See if this helps

 

For whatever it's worth my 11' Rubi Unl. w/ about 13k miles pinged very slightly on slow steep uphills; I put in 91 when I know I'm going to be doing some of those types of hills and it goes away. Everyday driving I still use 87 w/ no pinging.

 

My JK is... was... prone to ping. Same exact manner you described.

I always run 87 when I can. Running 89 would typically fix the detonation issues.

First improvement made - swapping plugs. Plugs I ran had a tighter gap than factory specs called for. Not sure if that was the source of the improvement, but regardless I didn't bother regapping them. They were NGK GP Platinums, or G+ Platinums - something like that.

Over time the pinging came back. I figure from the plugs getting worn. Sometimes it was worse than others. Running 89 still fixed the pinging.

Then I installed a axle back exhaust. JK seemed more prone to ping - more sensitive to good or bad 87 octane fuel. Running 89 would make a big improvement in detonation and performance.

Then I installed a tuner. Fixed some of the common pinging, but also brought in some new deep throttle rattles when running 87.

Then I installed a PCV catch can. This made a BIG improvement. Got rid of about 90% of detonation. I have some info posted here: Installed a PCV catch can.

So my thoughts....... Run 89, and see how things go. If you're due for plugs, try swapping them. If you still need help - I'd go for the catch can.

 

My 6-speed 2010 with 30,000 miles pings on 87 and 89 octane. I've tried several different tunes from my Superchips and it hasn't seemed to make much of a difference.

 

Run a bottle of RXP in your tank for the next couple of fill ups. With modern engines and OBD II computers, upping the octane will not help. RXP will not increase HP or MPGs... it simply burns out any carbon buildup you might have.

 

Where did you get the catch can from?