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2014 Jeep Wrangler, Dire sound after starting Tap/Knock/Rattle goes away

Thanks in advance anyone for their time. I’ve explored every corner of the internet trying to find the same noise.

Upon starting the engine there is a loud tapping, doesn’t sound like a deep knock or rhythmic lifter ticking. It started off very minor, and has slowly gotten much worse. It is loud enough to be heard by anyone in the immediate area, maybe a couple hundred feet.

In every instance so far, it diminishes until gone when all warmed up and the Jeep drives absolutely fine, as good as new in fact. nice and quiet. It is throwing no codes. There are no odors or smoke. I have eliminated the possibility of anti drain back valve, oil filter issue. The oil is fresh and sea foam was added.

One mechanic watched the below youtube videos and says the fact that it’s not rhythmic in time with the engine throws him off. Perhaps someone here can recognize what is going on?

When I turn the key with the gas pedal pressed down to prevent the engine starting the noise is present.

I’ve spent a few days trying to learn online all the various noises and causes, and come up pretty empty. If I had to pick one thing I believe it could be, It’s a loose timing chain banging on its cover and as the engine warms and oil pressure increases the tensioner is finally able to reel her in. But cant get anyone to say yep that’s likely it.

Editing just to add, not coming from the cats, which are bolted directly to block, unless the sound somehow travels or radiates from the rear to the front area of the engine.

First video, right after starting: https://www.youtube.com/watch?v=0p45DOBOBLg

Second video, after running a minute or two and calming down: https://www.youtube.com/watch?v=xvQs0mhRWcQ

That is a lot of text with no information about your vehicle at all. We know it is a 14 Jeep Wrangler but nothing else. Please post mileage, engine type, trans type and how long this has been going on.

Also tell us… has it been to a shop to diagnose the problem? Not just sending a video to a mechanic…if I can’t listen with my ears, and touch it with my hands, I can’t tell the location.

Also, what would you do if I told you what it was? Go tell, a mechanic to fix what I said? Or try and fix it yourself? That is important because “hands-on the Jeep” beats a guy on the interwebs all day long.

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Ok, I am new to the site. I thought I had entered everything in drop down about what the vehicle is. In my research I kept ending up on this site, so I deliberately entered more information than every post I came across here about the noise, what I have tried and what I have noticed, as most posts are back and forths extracting this information, and none of them contained video or audio at first. I have not been to a shop yet. Every Jeep JK of this era has the 3.6L Pentastar. With any information learned here yes I would perhaps try and fix myself, or at least learn where to start and if anyone else has experienced the same and what it ended up being, i’ll take the challenge and discuss with others who enjoy the challenge before just rolling over and paying whatever it takes without taking a stab myself. 141k miles, auto transmission

The noise is seriously weird. I have never heard anything like it. A wild guess would be a broken flywheel… Not an easy DIY.

It is impossible to determine where it is coming from listening to a video. You might be money ahead to take it to a shop so they can hear and feel it. Anything making that much noise should light off some vibrations.

You need a stethoscope or something to determine where the sound is coming from. I had what sounded like valve chatter after start up on cold days, ended up being a bad tensioner.

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Definitely an odd one and does not quite sound like a timing chain to me. Have you considered removing the serpentine belt and starting it up for a few minutes with all accessories inoperative to see if the noise goes away?

This will not hurt a thing and I was just pondering maybe an A/C compressor clutch in the beginning stages of failure or worst case a harmonic balancer failure.

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Someone at allpar.com may be able to help. They specialize in Chrysler products. I’ve found help on their minivan forum. You’ll find Jeep forums there, too.

That’s the first place I ever heard of a cracked flex plate, which bears investigation. Good luck!

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Thank you that’s a good idea, will definitely try that. Took about 10 minutes to calm down today and then its just absolutely fine.

Yes I must do this, I have a mechanic with the right listening tools going to look on Monday. I also heard of the one where you stick a narrow enough hose down into where the dipstick goes and if its in the chamber there it will be obvious, and loud in the hose.