Rattle from engine when accelerating (sounds like keys)

[LoJac963]

https://youtube.com/shorts/5g1xTFdpSMk

Mines been doing it since 3k miles. The dealer couldn't find the issue. The sound is getting really anoying.

You're sounds like it happened with you accelerated quickly? Mine and others is at a lower RPM like an engine lugging sound. Yours might be something rattling underneath if it's on a hard acceleration.

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[shokker70]

I guess I'm glad to know I'm not alone with the odd engine noise. Unfortunately, mine doesn't sound like the other descriptions or either video linked. My 1st impression of mine was more like "dieseling" when you don't down shift with a stick. Now I'd say it's more of a flutter, and very brief. Maybe a second long.

As someone else mentioned, no code, so they have no clue what it is, even though they were able to hear it. Mine can happen really at any speed. Definitely not only while accelerating. I've heard it at 30, and 65+ on the highway. It's really starting to get on my nerves. Can't always have the radio volume at 25.

As for flashing the system, they've done that twice since I reported the issue. No help, and seems to me it made my shift points worse. I've had 35s since day one with stock 3.73, Gas mileage dropped from 18-20 to 15-17. Rarely see 8th gear any more. Wasn't always the case.

 

[ShadowsPapa]

My 1st impression of mine was more like "dieseling" when you don't down shift with a stick.

Just to clarify for on-lookers -
That's actually the ping or rattle of detonation. Extreme high pressures in the combustion chamber under the low RPM load causes detonation.

Dieseling is the old carbureted engines that "ran on" due to hot cylinders and excess fuel getting in after shutting it off.
You won't get the run-on or 'dieseling effect' with fuel injection.

 

[JeepCares]

I guess I'm glad to know I'm not alone with the odd engine noise. Unfortunately, mine doesn't sound like the other descriptions or either video linked. My 1st impression of mine was more like "dieseling" when you don't down shift with a stick. Now I'd say it's more of a flutter, and very brief. Maybe a second long.

As someone else mentioned, no code, so they have no clue what it is, even though they were able to hear it. Mine can happen really at any speed. Definitely not only while accelerating. I've heard it at 30, and 65+ on the highway. It's really starting to get on my nerves. Can't always have the radio volume at 25.

As for flashing the system, they've done that twice since I reported the issue. No help, and seems to me it made my shift points worse. I've had 35s since day one with stock 3.73, Gas mileage dropped from 18-20 to 15-17. Rarely see 8th gear any more. Wasn't always the case.

We're sorry to hear that you are experiencing this concern. If you would like any additional assistance, our team is always available via private message!

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[flipmode]

I guess I'll add mine to the list now.

Just rolled over 20,000 miles, regular oil changes, no codes. I've run 93 octane for a few weeks now and it still sounds exactly like LoJac's recording:

I finally captured this noise I've been recently experiencing.

I disconnected my Start/Stop eliminator because I had read messing with ESS can cause engine lagging/knocking so wanted to rule that out.

This happens when shifting from 2nd to 3rd (automatic) just above 2000RPM, once the shift happens giving some extra gas causes the noise to occur. It is easily reproduced but difficult to capture on camera.

Any ideas??

Thanks in advance!



You do have to turn your volume up

Starting the dealer diagnostic BS this week, so I'll share the results if they are interesting or helpful.

 

[DAVECS1]

Well this is probably a consequence of the latest software update. It pulls back on the misfire detection to keep the avengers light at bay. The problem is the VVT tables are for the wrangler and are marginal for the Gladiator. On top of that the phazers can get stuck or dirty and things get real ruff. First thing to try is a fresh clean oil change with good oil and see if the dealer will run the phazer cleaning process with the starscan tool.

 

[LoJac963]

I guess I'll add mine to the list now.

Just rolled over 20,000 miles, regular oil changes, no codes. I've run 93 octane for a few weeks now and it still sounds exactly like LoJac's recording:

That sucks. I wonder how long it has been going on but you haven't caught it. The sound can be very subtle but given the right circumstances it can sound terrible.



Starting the dealer diagnostic BS this week, so I'll share the results if they are interesting or helpful.

Well this is probably a consequence of the latest software update. It pulls back on the misfire detection to keep the avengers light at bay. The problem is the VVT tables are for the wrangler and are marginal for the Gladiator. On top of that the phazers can get stuck or dirty and things get real ruff. First thing to try is a fresh clean oil change with good oil and see if the dealer will run the phazer cleaning process with the starscan tool.

I do wonder if the latest update had anything to do with it. They supposedly did a software update to mine when they did the steering box.

 

[ShadowsPapa]

Well this is probably a consequence of the latest software update. It pulls back on the misfire detection to keep the avengers light at bay. The problem is the VVT tables are for the wrangler and are marginal for the Gladiator. On top of that the phazers can get stuck or dirty and things get real ruff. First thing to try is a fresh clean oil change with good oil and see if the dealer will run the phazer cleaning process with the starscan tool.

Interesting - what's the cleaning process, how does that work?

 

[DAVECS1]

Interesting - what's the cleaning process, how does that work?

As far as I can tell the Starscan tool takes the engine to RPMs that allow it to rack the phazers back and forth rapidly without stalling the engine. It does it at a couple different RPMS and then shuts off.

 

[ShadowsPapa]

As far as I can tell the Starscan tool takes the engine to RPMs that allow it to rack the phazers back and forth rapidly with stalling the engine. It does it at a couple different RPMS and then shuts off.

Interesting, that makes sense. Sort of a quick scrubbing, perhaps past the normal travel range under normal driving conditions.

 

[flipmode]

I believe someone mentioned this earlier in the thread about our manual addressing 'light knocking'. I found it on page 478 (480 if you have the PDF):

I'm interested to know what qualifies, and what light knocking over the lifetime (and I'm expecting double digit years here) will have in the long term for an engine with this high compression ratio.

Also, and I hope I don't get roasted for a potentially stupid question here: but I noticed on my last 2 oil change receipts, the dealer has put in 6 quarts of oil in- the manual specifies 5. Is having an extra quart of oil rolling around in there going to have any adverse affects- like rattling or pressure issues? I (naively) assumed they would know.

 

[ShadowsPapa]

I believe someone mentioned this earlier in the thread about our manual addressing 'light knocking'. I found it on page 478 (480 if you have the PDF):

I'm interested to know what qualifies, and what light knocking over the lifetime (and I'm expecting double digit years here) will have in the long term for an engine with this high compression ratio.

Also, and I hope I don't get roasted for a potentially stupid question here: but I noticed on my last 2 oil change receipts, the dealer has put in 6 quarts of oil in- the manual specifies 5. Is having an extra quart of oil rolling around in there going to have any adverse affects- like rattling or pressure issues? I (naively) assumed they would know.

Remind your dealer - a good one will do it over and not charge you.
No, there's enough room in these that 1 quart doesn't appear to do damage. IF it did, there'd be hundreds of damaged engines.
The "rattle" is detonation. Fuel octane can actually vary a bit - I posted elsewhere here about how octane is actually "mapped" on gasoline so 2 87 octane fuels can behave differently in different engines at different RPMs.
Buy a top tier fuel - you can find your top tier stations by searching via google or bing.

Check with your dealership, too - the EGR system may be not working correctly, could be other factors in play. Occasional light pings - very occasional, not a huge issue, but longer term, and frequent, big troubles.
The compression ratio is a static measure. The engine can play with that number - the dynamic compression ratio, by changing valve timing and lift. If the cooling system is less than perfect, etc. you run into hot spots causing the ping.
Check with the dealer, try a top tier fuel.

 

[legacy_etu]

I know wrong spark plugs have been mentioned here but how about checking the gap? I've seen correct spark plugs with a bad gap. Easy to check too.

Yeah, also agree that datalogging could shed a lot of light on this.

 

[Mkcagle]

Note from mechanic “Found and removed keys, rattle gone”.
(old Navy maintenance control joke)

 

[legacy_etu]

Note from mechanic “Found and removed keys, rattle gone”.
(old Navy maintenance control joke)

Ha. Reminds me of the days I used to drive for UPS. At the end of your day you had to fill out a truck log describing any problems with the truck (even if there were none). These are a requirement from the DOT. Anyway, my truck would jump out of 3rd gear every day going up this hill. I'd have to hold the shifter forward to prevent this from happening. After like a month of noting this in the log the mechanics always responded "truck drives fine, no problem found". I finally got tired of it and wrote something to the effect of the truck is a danger to be on the road with this issue. Miraculously the truck was fixed that night.

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