Hi all. Looking on the forum for a fix for my 07 JKU. Couldnt really find a solid answer, so if its on here already, i apologize for the repeated question.
At operating temperature the engine rattles and pings under load (acceleration). I've tried seafoam to clean any carbon build up. The first time I tried it I dont think I did it properly, by I tried it again and got a tonne of smoke...didn't really improve the pinging though :(
I'm running 87 octane gas, as thats what the owners manual calls for. I've changed the plugs and checked oil level and changed the air filter. Still pinging.
I have a new set of plug wires ordered to see if that helps.
I've considered the chance that there may be timing issue, but these things are controlled electronically as far as I know...I'm not really savvy with this stuff,
Any help is much appreciated.
Cheers

 

Are you sure it's not a heat shield rattling when the engine torques over a little?

Severe, continuous knock may be caused by carbon deposits, bad gasoline, and/or low octane fuel.
Another possible cause is a faulty knock sensor, or its wiring.

Have you checked for a code that may have been set?

 

I don't think it's an exhaust heat shield, as it only happens when the engine is warm and only under load. When the engine is cold the engine sounds fine. Not to sound stupid, but how do you check for a code?

 

There is a key routine you can do, but not all codes show with that method. Your best bet is to get a scanner, or go to an auto parts store; some of them will scan your Jeep at no charge.

Here is how to do the key routine:

To check your Jeep JK Wrangler’s DTC codes:
1. Insert your key into the ignition, turn it to the ‘ON’ position but do not start the engine. (Make sure it's ON, and not just Accessory.)
Then, push the key into the ignition cylinder and while holding it in, turn it to the ‘OFF’ position and then back to the ‘ON’ position (3) times straight making sure to end with it in the ‘ON’ position. It is important to keep pushing in on the key to prevent it from catching at the different positions along the way.


2. If you do step #1 correctly, all your dash lights will illuminate and your odometer will show up as a series of (6) dashes. If your Jeep JK Wrangler has logged any DTC’s, they will be displayed soon after the dashes appear. Write down the DTC(s).

3. If your Jeep JK Wrangler has not logged any DTC’s, the dashes on your odometer will be followed by the message ‘-done-’. Turn your key to the ‘OFF’ position and you will in fact be done.

 

Thanks Ron,

I'll try this tomorrow. If there are codes displayed, where would I get details on what they mean? Sorry...I'm like the riddler with the questions

Cheers

 

Post the code, and I'll post the details from the service manual.

 

You didn't just buy this, did you? More important, has it pinged like this as long as you've owned it? I'm just wondering if a previous owner may have used a tuner for higher octane gas, then he or the dealer forgot to pass the tuner along to you. If the answers are yes, you might just try a higher octane gas.

 

If you go to 89 octane gas it should cure the problem. My 07 does the same thing when I run 87.

 

My 2009 is the same way. Must run 89 octane. I gave it a tune up but it didn't help. I used a couple cans of the Mopar combustion chamber cleaner and it seems like it helped. Since new it only pings when outside temps are warm. Pinging is mentioned in the owners manual so it must be somewhat common.

 

I had a ford explorer that developed this problem. Most people on the ford forum said it was caused by an air leak in the intake manifold. What fixed my problem instantly was using at least 91 octane. I too did the seafoam with no improvement. I ran that way for several years, only using 91 octane. A couple of times I screwed up and put 87 or 89 in. The pinging would return within a mile or two of the gas station. It was that noticeable.