Hi folks - sorry to jump right in with a question as my frist post but I'm desperate for advice.

My 2010 standard transmission Rubi (30,000 miles) has a "knock" in the engine - we used to call it valve clatter or premature detonation. The problem is not constant, but consistent enough to make me batty. Usually appears when short shifting - like heavy traffic situations, under load like backing up my very steep driveway, or accelerating to pass on the highway.......

Been to the dealer three times and since they can't hear it when it's in the shop - and since the computer shows no "codes" they tell me I don't have a problem.

I actuallu put the service advisor in the Jeep and HE HEARD it, but since the mechanic didn't hear it and couldn't replicate it when he drove it, and there was no code, they just handed it back to me - it was clattering again before I got home. I even asked if the "code" giver could be broken or perhaps a bad knock sensor, but the answer was they couldn't tell since they weren't getting a code - shessh.

And it does it no matter what brand or octane gas I use - even ran injector cleaner and fuel treatment through it.....

Any advice is most appreciated.

Thanks fo your time,
Gary

 

Hey Gary. Go to the dealership and get a can of Chrysler combustion chamber cleaner. It will remove carbon from the valves, which tends to be the cause of the pinging. It is sprayed directly into the throttle body. Allow the engine to sit for longer than they recommend. It may take two treatments. Also it wouldn't hurt to run seafoam through the gas tank. Does your motor consume oil? If so, have you changed the pcv valve?

 

Ryan - thanks allot - I'll head over tomorrow and pick up a can of the cleaner - and no sir, so far the engine hasn't used oil (at least by my standards) but I may change the pcv anyway if you think it might help -

Gary

 

I dealt with the same problem, and this treatment helped mine. I tend to do a lot of stop and start driving, and short frequent trips. Your driving style can play into the carbon buildup, and may need more frequent cleaning.

 

My 2010 Sahara did the same thing until I switched to plain 10w-30 oil. Purrs like a kitten now.

 

That will take care of valve train noise, but not predetonation. Two different things.

 

I went through this with my 2010 and it nearly drove me nuts. I tried everything - different octane, different brand of gas, replaced the knock sensor, disconnected the battery overnight, etc...

Here's the thread
Still pinging! Why?

...basically, in the end I convinced myself that the motor was simply being asked to do too much - I may have had 3.21 gears (could have ben 3.73, can't remember) - but that plus the slightly larger/heavier tires (tried 32" and also 33", while it came stock with 29's) and loading things up with some cargo was just too much for the 3.8L V6.

But you say you have the Rubi, so you must have 4.10 gears - so I'm surprised you're running into this. Is your jeep loaded down with heavier stuff (big tires, 100 lbs bumpers front and rear, etc.)?

 

No sir - she's bone stock and boring and the heaviest cargo I carry is a 30 lb Border Collie -

I think Ryan is on to something here though - I only have 30,000 miles on it but that has ALL been stop and go driving in heavy traffic - due to family illness, I haven't been able to leave the City long enough to get her off road yet (except for the occasional late night blast through construction sites - but there is NO video evidence proving it was me) - soooo - - I'm bound to have carbon build up in the combustion chambers - I have my can-o-cleaner ready to go AND since I'm in heavy traffic in the Texas heat - I'm also taking Goofas's advice and changing the 5w 20 to 10w 30.

I'm doing both this weekend so hopefully my rattle trap will settle down. I've been driving Jeeps since 1989 and never had this problem before so I wasn't even thinking of oil viscosity or carbon build-up - ---- - - man I miss the old straight six 4.0L - that was a helluva motor from my experience.

I'll post up in a couple of days and let you guys know how it turns out - - thanks again for all your advice...

Gary

 

Border collie - world's smartest dog.

My first Jeep was the 3.8L V6 in 2010, and as much as I love my new Pentastar 3.6L V6 so far, I so wish it were a straight six configuration. And in diesel at that...

Anyway, sounds like with a stock rig on 4.10s you shouldn't be experiencing what you're experiencing. Who knows; maybe it's a bad knock sensor after all - though seems so unlikely; there's not much that can go wrong with the knock sensor. I wonder if changing the oil type is only masking a problem though - I mean how would changing to a different viscosity make the knocks quiet down? might muffle them but I suppose it's possible things will run cooler so pre-detonation isn't happening... but seems unlikely. Can't hurt to try though.

Knock sensor replacement should be cheap and easy, I just have my doubts based on my experience with my 2010 2-door.

Looking forward to hearing what you find out.

 

I have a 2010 Sahara 3.73 gears and running 33's. right about 2500 RPM going up a hill the knocking starts. I've replaced the PVC, egr valve and nothing changed. Oh and mine burns a quart of oil every 1000 miles. My best fix so far is louder muffler and turn up the radio.