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Anybody got SPARK KNOCK????

Old Nov 26, 2009 | 05:37 AM
  #11  
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My 08 auto has it also...just started up about a week ago. Jeep said there's nothing wrong with it.

I haven't really done anything for it yet, but it seemed to clear up a bit after a 1000mi highway trip. Now that I'm back in the city and have fueled up, it's back. I only run 87 with no tuner.
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Old Nov 26, 2009 | 01:08 PM
  #12  
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my 08 pings and knocks while going up hill under load, I only run 87 and it has been like this since new. never really thought much about it, just figured that is what you get with a minivan engine.
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Old Nov 26, 2009 | 01:18 PM
  #13  
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I have never heard and knock in my Rubi at all. I tow a travel trailer and have been thru the mountains in Colorado going to Moab, and never had a problem while towing.

Is it possible you are getting bad gas???

Have you run any injector cleaner thru the system like Techron with a tank full of premium to clean out carbon build up?


Other wise these engines should not knock.
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Old Nov 26, 2009 | 01:21 PM
  #14  
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does anyone have a sound clip of this knock or pinging?
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Old Nov 28, 2009 | 02:02 PM
  #15  
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It generally is going to sound like pebbles rattling in a coffee can.

Most of the time you can't even hear it above normal engine/road noise.
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Old Nov 28, 2009 | 07:50 PM
  #16  
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Mine has done it for almost all of my 40k miles. If I jump up to 89 octane I don't have the problem, and usually the 87 at chevron is okay. Mine doesn't seem to be really bad so I live with it and if I know I will be doing some mountain driving where I will be working the engine I make sure to run 89. For a while I thought it was an exhaust rattle but I have been unable to find an exhaust rattle so I continue to assume pinging.
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Old Nov 30, 2009 | 01:32 PM
  #17  
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I get some knocking in 4hi when I'm on the beach. In the deeper sand. Going about 10mph.
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Old Dec 1, 2009 | 06:35 AM
  #18  
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I have a 09 Rubi 2dr AT and if I let it lug just a littel bit it will ping very slightly. Keep the rpm's up and no ping at all.
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Old Dec 5, 2009 | 11:32 AM
  #19  
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Ok, I found some info on this problem with the 3.8L. I have an 08 4dr rubbi with 14,500 mls. on the odometer. I treat it pretty good but recently, at about 12,500 I had turned down the radio and noticed the exact problem.
To be precise the noise appears approximately at 2k to 3k rpms and generally you'll hear this when a load is placed on the engine.
Deal with it fast! I took mine into the dealer and learned to my horror that I had over 1/4" carbon buildup in the intake! Very important to note is that Chrysler does NOT warranty carbon buildup after 12k miles! The dealer had my JK for 4 days trying to solve the problem. A bore scope will show the detail or they can remove the vent tube.
They performed two intake flushes and had to do an oil change! Fortunately, this they did for free! Most will not and Chrysler refused to foot the bill!.
Now, I have more power and better fuel economy. To place a point to this, I don't buy cheap fuel. I use premium Penzoil synthetic oil and change at 5000 mls.
The service manager told me to specifically use either Shell fuel or fuels that use cleaners! Very important is that you also keep your fuel receipts and write down the mileage.
Good luck!
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Old Dec 6, 2009 | 03:52 AM
  #20  
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Originally Posted by Crazy_Ivan
Ok, I found some info on this problem with the 3.8L. I have an 08 4dr rubbi with 14,500 mls. on the odometer. I treat it pretty good but recently, at about 12,500 I had turned down the radio and noticed the exact problem.
To be precise the noise appears approximately at 2k to 3k rpms and generally you'll hear this when a load is placed on the engine.
Deal with it fast! I took mine into the dealer and learned to my horror that I had over 1/4" carbon buildup in the intake! Very important to note is that Chrysler does NOT warranty carbon buildup after 12k miles! The dealer had my JK for 4 days trying to solve the problem. A bore scope will show the detail or they can remove the vent tube.
They performed two intake flushes and had to do an oil change! Fortunately, this they did for free! Most will not and Chrysler refused to foot the bill!.
Now, I have more power and better fuel economy. To place a point to this, I don't buy cheap fuel. I use premium Penzoil synthetic oil and change at 5000 mls.
The service manager told me to specifically use either Shell fuel or fuels that use cleaners! Very important is that you also keep your fuel receipts and write down the mileage.
Good luck!
Where exactly was this carbon build up?
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