Its really bad when accelerating at lower rpms. I plan to check the manifold today and buy some seafoam to see what I find.

 

I have a 6 speed and it cruises at about 21-2200 in 6th gear at 70mph with 35's and 3:73's

 

Make sure you keep your rpms up. If your landing in gears at less than 2k there isn't enough torque to start you accelerating nor the power to keep you rolling. You can certainly drop your rpms to maintain speed but quite a different story to accelerate.

Here's a dyno chart so you can see where the torque curve begins to flatten out. Also, do your own test with your highway cruises in 5th gear at 70mph, estimated 2500-2600 rpm and note the changes in efficiency. If nothing else, the extra rpm will help blow some carbon out.

 

Didn't you say that dealer already ran a combustion chamber cleaner through your motor. I tried sea foam and it did nothing I took to dealer they ran their cleaner through it. After that was unsuccessful they took heads off and replaced the carboned up valves.

 

I added some seafoam in hopes that it will eventually help out with the carbon. I noticed this morning that the pinging is under acceleration at pretty much any rpm range. I work from home so I only drive to and from the gym during the week and I usually let it idle quite often. I'm reading on other sites that this may be the reason for carbon build up.

So, if it is in fact carbon build up, is there any easy fix? any additive that is specifically better than others? How harmful is it to the engine if I ignore it?

 

When I took mine in to the dealer and of course they didn't or couldn't duplicate it until I got in and drove it with the service manager. The service manager recommended I upgrade to 89/91 octane for a few tanks. So far I have 2 full tanks of 89 and I haven't really heard the ping. The ethanol I heard does make a difference. It's BS, but can we do, Vote in November for the better one.

 

Well my Jeep started pinging again about a month ago. Oil consumption has gone up to about 1 litre per 1000 km. Dealer is doing a consumption test now.

 

Is there oil in the air inlet tube or varnishing in the throttle body? What do the plugs look like? Any fouling?

 

I would try the Chrysler combustion chamber cleaner. About $10 at the dealership. Introduce it through the throttle body and allow it to sit as directed. Run it through and change the oil immediately

 

Just curious as to how you drive it? Short frequent trips? What kind of rpm range do you drive in? I have changed my driving habits somewhat and it has helped some with the pinging.