Rattle from engine when accelerating (sounds like keys)

[ShadowsPapa]

that’s why I’m trying to get them to figure it out. It is not normal! I would hate to just deal with it and never report it then 20-30k mile down the road have engine problem. Shouldn’t be happening. Thanks for all the detailed explanation of spark knock/detonation.

You're welcome - I need to use that experience and expensive training for something LOL.

There are several videos on YouTube of the noise on film. Post up your phone, or a good camera, in the cab and try to record it. Obviously no radio or talking and try to hit your light (lugging) acceleration pattern that causes it several times before you stop the recordnig.

Videos can help if one keeps in mind that the mics in phones are, well, phone microphones and not what Phil Spector would have used for reproducing sounds you want to compare to original.

They are very good for the pattern and what's going on with the truck - the conditions at the time the sound occurs, most of all, IMO.
Me - I want to be there and hear it for myself - but I can also go by the description and CONDITIONS that you have to meet to repeat the sound.

I would absolutely get a recording - BUT I would NOT do it myself - I'd have someone else in the truck with the recording device as it's just plain stupid to try to mess with a phone for photos or VIDEOS especially WHEN DRIVING and trying to concentrate. People have died trying to be smart and getting pics and recordings when driving - hell, they die when simply talking on the phone or texting and that's easier than making a recording and duplicating specific conditions at the same time.

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[zprovo]

I also have this exact issue. On other cars, I had always called the noise pinging like when you use cheap gas or if I set the timing off on my '86 land cruiser.
I currently have 19,500 miles and first noticed it this past spring when I took the doors off. I put 93 octane in the tank next fill up, that seemed to help a little. But then I read on some forum that these motors "learn" your gas and driving habits so I went back to regular gas.
I plan on bringing it to the dealer for it's 20k service in the next week or so, so hopefully they will have some thoughts. If it is detonation it sure would be swell if the truck would record a code...

 

[ShadowsPapa]

Here's some interesting information related to another article I SWEAR I read about modern engines doing better with the 87 vs trying higher octane fuels - especially since there are differences in octane numbers - and differences between the octane numbers for gas vs ethanol. The ocane rating at the pump is a forumula something like RON+MON/2.
That's research method vs motor method.
There's a spread between the two for gasoline of about 8 or so, and of about 14 for ethanol. That means there's a wider difference between the RON and MON of ethanol than there is between the two for gasoline.
It's been found that engines with knock sensors perform better when there's a wider spread - in other words, when there's a lower MON for a given RON.
What has the wider spread? Ethanol.
And it's more thermally efficient.
So it's possible that if someone is using straight gasoline with no ethanol, they might try a top tier ethanol blend and see if there's a change.

(Octane for ethanol is an ESTIMATE ONLY as certified octane engines are ALL carbureted and aren't capable of testing pure ethanol. So it's based on the BOV (blend octane value - how much octane of the gas goes up with ethanol added, and doing a lot of math. There is no TRUE octane value for ethanol based on actual MON testing. So - my avove numbers for ethanol are based on the impact it has when blended with gasoline.)

 

[bwm2020]

I also have this exact issue. On other cars, I had always called the noise pinging like when you use cheap gas or if I set the timing off on my '86 land cruiser.
I currently have 19,500 miles and first noticed it this past spring when I took the doors off. I put 93 octane in the tank next fill up, that seemed to help a little. But then I read on some forum that these motors "learn" your gas and driving habits so I went back to regular gas.
I plan on bringing it to the dealer for it's 20k service in the next week or so, so hopefully they will have some thoughts. If it is detonation it sure would be swell if the truck would record a code...

That’s about when mine started. 18k. 40k and still ticking. Lol!

 

[JT202006]

I get the same thing started at about 16k, I would explain the noise as more pneumatic sounding. Almost like a blow off valve. Of course dealer said they couldn’t hear it...

 

[zprovo]

Have any of you noticed a drop in performance that accompanied the rattle? I have definetly noticed a mild bog that happened at the same time.

 

[Punkinpuddin1031]

Have any of you noticed a drop in performance that accompanied the rattle? I have definetly noticed a mild bog that happened at the same time.

Not noticeable if there is power loss.

 

[ShadowsPapa]

Have any of you noticed a drop in performance that accompanied the rattle? I have definetly noticed a mild bog that happened at the same time.

Could be lugging it - that means you are too low in the RPM power band and it's struggling. That will cause detonation. One can force it...........
Automatics should downshift once you lug it - and it could be that if you have an automatic, you need the PCM flash (check with your dealer - if your VIN is listed as needing the flash they'll let you know) as it sure solved my transmission shift pattern weirdness.

 

[iGlad]

I have been looking through some other forums. Found this one: https://www.wranglerforum.com/threads/predetonation-fix-3-6-pentastar.924313/

Post #7:
"Some of the most common causes of knock are these:

1: bad knock sensors.
2: engine running too hot
3: EGR valve failure
4: Improper octane
5: poor quality gas
6: incorrect spark plug
7: low oil
..."

Curious if the dealer looked at any of these things mentioned? (other than the change in gas) @bwm2020

 

[ShadowsPapa]

I have been looking through some other forums. Found this one: https://www.wranglerforum.com/threads/predetonation-fix-3-6-pentastar.924313/

Post #7:
"Some of the most common causes of knock are these:

1: bad knock sensors.
2: engine running too hot
3: EGR valve failure
4: Improper octane
5: poor quality gas
6: incorrect spark plug
7: low oil
..."

Curious if the dealer looked at any of these things mentioned? (other than the change in gas) @bwm2020

The PCM flash addresses some EGR issues. But a dealer that runs the VIN when they take a vehicle in would be alerted of the PCM flash need.

It was said the engine is not running over-temp, but the knock sensor thing is possible.
Spark plug - not likely on an engine that's not been messed with, improper octane - as long as he's running 87 it's fine but I do suggest if it's 87 PURE gas to try a top tier 10% blend 87 octane.

I laugh at the title of that Wrangler thread - predetonation - that's a good one.

 

[zprovo]

Could be lugging it - that means you are too low in the RPM power band and it's struggling. That will cause detonation. One can force it...........
Automatics should downshift once you lug it - and it could be that if you have an automatic, you need the PCM flash (check with your dealer - if your VIN is listed as needing the flash they'll let you know) as it sure solved my transmission shift pattern weirdness.

This truck is my first vehicle with an automatic transmission. To your point I would assume it would shift down prior to lugging and detonation, but it doesn't.
In October I took my boys on a camping trip to Cape Lookout. Driving in deep sand the truck would sit in 3rd detonating like a volkswagen dasher diesel until I manually shifted and held it in second. Sounds like I need that flash...

 

[bwm2020]

I have been looking through some other forums. Found this one: https://www.wranglerforum.com/threads/predetonation-fix-3-6-pentastar.924313/

Post #7:
"Some of the most common causes of knock are these:

1: bad knock sensors.
2: engine running too hot
3: EGR valve failure
4: Improper octane
5: poor quality gas
6: incorrect spark plug
7: low oil
..."

Curious if the dealer looked at any of these things mentioned? (other than the change in gas) @bwm2020

They have checked all that, even changed oil specifically to see if that helped in the beginning of issue. Received call from Jeep Cares today, just waiting on call from dealer to figure out field tech coming. Then Dealer says same thing, trying to get up with the other. Phone tag!

 

[bwm2020]

Update!
So I was just inform Chrysler is not sending a field rep out due to COVID. Seriously!!!!

 

[LoJac963]

My thread was linked earlier but not mentioned, is this the same sound you are getting??

This is what I posted on my thread:

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.



at the 3 second mark, have to turn your speakers up a bit

 

[AustinL911]

FCA employee came to work drunk and put a pop can in a frame rail.

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