'10 JKU Engine Noise

[ThatCherokeeGuy]

Ok, I picked up a used '10 JKU about 7 months ago and its been running great. Lately though, I been hearing rattling noise when I press the accelerator (like going up a hill to maintain speed). Its not a knock, and I have no check engine or any other warning lights. To me it sounds like an exhaust bracket is loose, any body else have had this problem? Hoping that its not a serious issue.

 

[Bennyhana]

Check the little heat shield on the exhaust pipe that crosses under the trans. They are notorious for having a couple of the tack welds breaking and rattling.

 

[GFA]

My 2010 does the same when under load. Sounds like spark knock to me but I'll have to check the heat shield.

 

[ThatCherokeeGuy]

Check the little heat shield on the exhaust pipe that crosses under the trans. They are notorious for having a couple of the tack welds breaking and rattling.

Thanks for the suggestion! Hoping to be able to crawl around the jeep today...weathers been a little to wet.

 

[ThatCherokeeGuy]

Is it true you can elevate spark knock with a higher grade of gasoline?

 

[dstock]

I had the same issue with my 2010, higher octane gas helped but would not make it go away. My guess was the slowly increasing use of oil was causing carbon build up on the heads. The Jeep owner's manual indicated that for the 3.8L a quart of oil every 1000 miles was normal consumption which to me seems absolutely ridiculous in this modern age. My oil usage was not that bad but it was disappearing somewhere despite the fact there were not any leaks and you could not see any obvious oil being burnt in the exhaust. I decided I did not have the time or the patience to go through the "oil consumption" test process with the dealer and traded it in for a new 2013 Rubicon with the 3.6L. I will say I have not regretted the decision at all. I know this isn't the solution for everyone but the "pinging" was driving me nuts.

It is true the heat shield on the crossover exhaust pipe can break and cause a similar noise, just was not the issue in my case.

YMMV

 

[Idahoan]

Is it true you can elevate spark knock with a higher grade of gasoline?

Not in my experiences. This rattle sounds like preignition. I'd through new plugs in it and see if it goes away.

 

[ThatCherokeeGuy]

I had the same issue with my 2010, higher octane gas helped but would not make it go away. My guess was the slowly increasing use of oil was causing carbon build up on the heads. The Jeep owner's manual indicated that for the 3.8L a quart of oil every 1000 miles was normal consumption which to me seems absolutely ridiculous in this modern age. My oil usage was not that bad but it was disappearing somewhere despite the fact there were not any leaks and you could not see any obvious oil being burnt in the exhaust. I decided I did not have the time or the patience to go through the "oil consumption" test process with the dealer and traded it in for a new 2013 Rubicon with the 3.6L. I will say I have not regretted the decision at all. I know this isn't the solution for everyone but the "pinging" was driving me nuts.

It is true the heat shield on the crossover exhaust pipe can break and cause a similar noise, just was not the issue in my case.

YMMV

As much as I would LOVE to get into a '14 Rubicon...can't quite go this route. Like the suggestion though. :coffeedrink:

 

[ThatCherokeeGuy]

Not in my experiences. This rattle sounds like preignition. I'd through new plugs in it and see if it goes away.

Put some high octane gas in it this morning and it had some effect. Definitely going to check the spark plugs (thanks for suggestion), also going throw some STP cleaner in it to get rid of any deposits in the cylinders.