mostlystock

Switched from 93 to 87 octane a couple tanks ago, and tried new brand of gas. Still getting pinging when gently giving it gas, usually occurs around 2300 RPM, in any gear.

WTF?

Jeep is a 2010 JK 2-door with 3,300 miles, no mods except 2" lift and 33" Cepeks on alloys, corrected with AEV ProCal. No mods to fuel/intake/exhaust/elect/whatever.

Did I do something wrong by "training" my Jeep (first 1,000 miles) that it was going to always be fed 93 octane and be driven at around 2,000 RPM (probably 3K RPM max on shifting or passing, but rare)

Can I somehow force the computer to start from scratch an re-learn?

If that's the problem...

Maybe it's the load I'm putting on the jeep with the 33's? Hard to imagine...

itasor

I would disconnect the battery for a while.

Pape

owner manual say you can experience pinging at low rpm and it normal. That said 2300 is not low rpm for me 600 ~ 1500 is. next time you go to dealer voice your concerns about it

tpm152

Until you get this thing resolved if you know it is knocking, you should switch to 93 octane. Even though it is more expensive 93 is much more knock resistant than 87, so even if you still get knocking with 93 it should at least reduce any potential damage to your engine by paying the extra 4 dollars per fill-up.

Also if you haven't tried disconnecting your battery yet, I second that you should at least try that.

Alec

Yup, babying the motor can lead to carbon deposits which alter compression or create hotspots in the combustion chamber. Usually this doesn't happen over only 1000 miles but it can. I've had similar issues with my mother's and grandparent's vehicles in the past. Throwing in a bottle of techron and footing them up an on-ramp usually do the trick.

thrshr01

We need more info. What year, current mileage, mods (ie fuel system, ignition, engine).

Adam3612

One night about a year and a half ago I went to get gas and somehow the station I went to was out of regular (87) so they were offering 89 and 91 grades for the price of regular. I hauled out the owners manual and checked to see if there were any warnings against using higher octanes and I thought it said something along the lines of the engine could possibly start knocking if using anything about 87 octane, I ended up going to another station a kilometre down the road. I don't know how accurate this info is, so feel free to correct me if im wrong.

mostlystock

I just did. I'll let it sit until tomorrow morning. I've been running it a little harder today, mainly because I'm a little pissed off at it, so we'll see if it shapes up. I haven't heard anything definitive about whether or not the battery disconnect actually does anything -- after all, I'd bet most parameters these days are stored in nonvolatile memory -- but who knows... I'm ready to try anything. This just isn't right.

mostlystock

It's pung reliably on 87 and 93. Yes, my understanding is that higher octane is less prone to detonation (pinging) -- it's more stable. Still made my thing ping.

mostlystock

Some of it's in my sig... but my bad, should have specified. Will revise. It's a 2010 JK 2-door with about 3,300 miles on it, and the only mods are a leveling kit (2" coil spacer lift), and 33" Cepek tires on 16" alloys. Trailer hitch too, but only towed a light utility trailer to the dump 3 times, and it was pinging long before that. No mods to the stock fuel system, drivetrain or electrical (other than a ham radio rig, but it's just a radio receiver at this point).