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Rattle from engine when accelerating (sounds like keys)

ShadowsPapa

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What I dont understand is if the engine has detonation, why isnt the knock sensor correcting the issue???? Isnt that what it's for? If you have a bad knock sensor it will set off the check engine light, correct?
Traditionally, knock sensors caused timing to be retarded. If it's not detonation due to timing being too far advanced, that won't make a difference. Key word - traditionally.......... the knock sensors on these could trigger other things......

Mine has yet to ping and I've beat on it pretty hard now and then.


I have never seen the light, but I wonder how sensitive it is because my knocking generally never lasts more than ~1/2 second. It's very short and the transmission will drop to a lower gear - just not fast enough to prevent it from happening in the first place.
In that case, I'd not worry about it. Even the book says as much. I've had and driven cars for decades that have had minor ping due to detonation. As long as it's short, not way loud, and not common or often, I'd not bother.


So i know nothing about how an engine compression ratio works but i did google if the same engine from the factory can have different compression ratios and it said it can. Is this correct? Maybe our compression ratio is higher than the people that dont have pinging using 87?

Static compression ratio is 11.3
Dynamic can be lower or higher.
I wrote earlier on how even though I put heads on my 390 that had larger chambers in order to reduce compression, my adding free-flow exhaust manifolds and an xtreme energy cam - I ended up raising dynamic compression.
Engines can be more than 100% as far as pumping efficiency as the air has momentum going in, and the leaving exhaust can have scavenging effects - pulling intake gases in before the piston starts down.
Static compression is the comparison of the volume with the piston at BDC compared to the volume of the chamber at TDC.

Dynamic compression takes into account air moving in before the piston starts down, and continuing to move in as the piston passes BDC - "packing" the cylinder more than 100% full.

A normal burn is NOT an explosion - it's a progressive flame front moving through the compressed gases. It takes time to burn.
Preignition is when the charge ignites before the spark. You have a flame front already advancing and then light the charge with the spark - and the two fronts collide.
Detonation is when the normal flame front compresses the unburned fuel/gases into a "corner" and the pressure and heat rises to the point that the unburned fuel self-ignites and starts another flame front. The ping is the sonic boom of the two colliding resonating in the block and heads.

High octane fuel simply resists self-ignition. Doesn't burn faster, doesn't burn slower, doesn't have more energy, doesn't have less energy - it simply is a combination of other chemistry that resists self-ignition when squeezed and heated.
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Below is how mine sounds (2021 Sport S 6 speed manual, 7400 miles). Sorry about the wind noise, but the rattles occur at:

0:19 - 0:27, 0:44, sustained rattling from 0:50 - 0:54, at the one minute mark and about 1:15.

It happens between 1500 and 2500 RPM (light throttle application) and sometimes between 2500 and 3500 (heavier throttle). Most always this rattle occurs on a slight upward incline. The rattles are much worse when its warmer and humid (above 85 degrees).

I plan to take this to the dealer next week for a checkup.

Thanks for the good recording, this is exactly how mine sounds. Appreciate your effort here.
 

SelfmodJT

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Traditionally, knock sensors caused timing to be retarded. If it's not detonation due to timing being too far advanced, that won't make a difference. Key word - traditionally.......... the knock sensors on these could trigger other things......

Mine has yet to ping and I've beat on it pretty hard now and then.




In that case, I'd not worry about it. Even the book says as much. I've had and driven cars for decades that have had minor ping due to detonation. As long as it's short, not way loud, and not common or often, I'd not bother.





Static compression ratio is 11.3
Dynamic can be lower or higher.
I wrote earlier on how even though I put heads on my 390 that had larger chambers in order to reduce compression, my adding free-flow exhaust manifolds and an xtreme energy cam - I ended up raising dynamic compression.
Engines can be more than 100% as far as pumping efficiency as the air has momentum going in, and the leaving exhaust can have scavenging effects - pulling intake gases in before the piston starts down.
Static compression is the comparison of the volume with the piston at BDC compared to the volume of the chamber at TDC.

Dynamic compression takes into account air moving in before the piston starts down, and continuing to move in as the piston passes BDC - "packing" the cylinder more than 100% full.

A normal burn is NOT an explosion - it's a progressive flame front moving through the compressed gases. It takes time to burn.
Preignition is when the charge ignites before the spark. You have a flame front already advancing and then light the charge with the spark - and the two fronts collide.
Detonation is when the normal flame front compresses the unburned fuel/gases into a "corner" and the pressure and heat rises to the point that the unburned fuel self-ignites and starts another flame front. The ping is the sonic boom of the two colliding resonating in the block and heads.

High octane fuel simply resists self-ignition. Doesn't burn faster, doesn't burn slower, doesn't have more energy, doesn't have less energy - it simply is a combination of other chemistry that resists self-ignition when squeezed and heated.
So obviously it has to do with heat then because it doesnt happen until the oil temp reaches about 180 degrees?
Traditionally, knock sensors caused timing to be retarded. If it's not detonation due to timing being too far advanced, that won't make a difference. Key word - traditionally.......... the knock sensors on these could trigger other things......

Mine has yet to ping and I've beat on it pretty hard now and then.




In that case, I'd not worry about it. Even the book says as much. I've had and driven cars for decades that have had minor ping due to detonation. As long as it's short, not way loud, and not common or often, I'd not bother.





Static compression ratio is 11.3
Dynamic can be lower or higher.
I wrote earlier on how even though I put heads on my 390 that had larger chambers in order to reduce compression, my adding free-flow exhaust manifolds and an xtreme energy cam - I ended up raising dynamic compression.
Engines can be more than 100% as far as pumping efficiency as the air has momentum going in, and the leaving exhaust can have scavenging effects - pulling intake gases in before the piston starts down.
Static compression is the comparison of the volume with the piston at BDC compared to the volume of the chamber at TDC.

Dynamic compression takes into account air moving in before the piston starts down, and continuing to move in as the piston passes BDC - "packing" the cylinder more than 100% full.

A normal burn is NOT an explosion - it's a progressive flame front moving through the compressed gases. It takes time to burn.
Preignition is when the charge ignites before the spark. You have a flame front already advancing and then light the charge with the spark - and the two fronts collide.
Detonation is when the normal flame front compresses the unburned fuel/gases into a "corner" and the pressure and heat rises to the point that the unburned fuel self-ignites and starts another flame front. The ping is the sonic boom of the two colliding resonating in the block and heads.

High octane fuel simply resists self-ignition. Doesn't burn faster, doesn't burn slower, doesn't have more energy, doesn't have less energy - it simply is a combination of other chemistry that resists self-ignition when squeezed and heated.
So in your opinon, how long do you think the engine will last if it continously detonates like the attached video? Wonder if oil has anything to do with it? I use penzoil, what do other people use? Or am i barking up the wrong tree lol.
 

ShadowsPapa

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So obviously it has to do with heat then because it doesnt happen until the oil temp reaches about 180 degrees?
So in your opinon, how long do you think the engine will last if it continously detonates like the attached video? Wonder if oil has anything to do with it? I use penzoil, what do other people use? Or am i barking up the wrong tree lol.
Yes, absolutely heat. One car I had detonated - until I put a new radiator in it. It was running just a bit more hot than it should even though the gauge was still in the green. Cooling it a few degrees helped.
Self-ignition of fuel happens because of heat and pressure. Compressing a gas heats it, if it's hot already, then compressing it (the advancing flame front of the burning fuel compresses the unburned fuel) and makes it hotter - and the fuel can self-ignite.

Oil type won't matter and it's not really the oil temperature - that's just an indication of an engine hot enough to have detonation.

Continuous detonation is risky - the collision of the flame fronts actually blows the protective boundary layer away from the top of the piston exposing it to the higher heat of combustion (normally there's an unburned layer of mixture that protects the piston top from the full force of the burn)
Mild occasional detonation isn't a big issue. Prolonged is an issue, and louder is worse than mild.
 

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Same n
Def let us know what the dealer says. If he says its normal ask him why it doesnt do it until the engine reaches operating temperature. Im pretty sure yours is also silent with no noise until the oil temp reaches 180 or so. I can understand the detonation at 1500 rpm or under, especially on an incline but above 2500? I cant see how thats normal. Im finally taking mine in next week because i dont have to wait for a stupid shock anymore, i bought rubicon take offs and replaced them today. If they say its normal, im going to have it in writing so i can document it and i will drive it regaurdless if it detonates on 87 octane because thats what the manual says. Detonation should get worse, right? Hopefully, they will address it before the 5yr, 60k powertrain warranty runs out.
If I hit the ‘sweet spot’ on a long, slight incline road, I can get this detonation rattle to happen continuously for 500-1,000 feet. My service dept keeps trying to avoid addressing the issue, but I also don’t care anymore because they admitted they heard it on the last work order (which I might laminate or frame) so when the eng does blow up, I got proof. My perception of most dealers is that they are morons, but maybe they really just dont know what to do because they get their instructions from the most corrupt car company (FCA) out there. So they try to avoid lack of quality issues like this at all costs. Who fn knows.
 

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Couple things. Oil may address the issued, if the cam phazer is not moving fast enough or correctly. A good flush and the correct weight synthetic, may just get it to stop.

The dealer does not want to address it because this is a bit complicated to do in a timely matter for your average mechanic.

My guess is this issue comes down to cam timing and ignition timing. The cam and cam phazer is set up in such a way, software or mechanically, that it is locking to much air into the cylinder at low load. It only happening when hot indicates this is probably a marginal tolerance stack up issue. Basically the heat is the differentiator that causes the quicker burn of the charge. That is a very thin margin of ignition.

Dealers do not have access to be able to recalibrate or tune and engine, they can only report to Chrysler/Jeep they suspect something is wrong, and then rhey have to depend on a service engineer to take their problem seriously and get the responsible team to release an update.

The dealer's direct options to fix the issues
1. Flush engine oil, replace with new and do a cam phazer cleaning cycle with the service tool
2. Replace the cam phazers on the engine.
3. Replace the camshafts on the engine
4. Replace the engine

Audible detonation in these new engines is not good. The compression is already high, and ot was designed as such, because it was given that the controls would eliminate all chances of that happening. The materials are stronger but lighter, not like older engines, they are not designed to take long term misfire. The rings are thin for fuel milage and will eventually crack or flutter out and acore a cylinder wall. Or you will fret the head gasket. This is an open deck motor.

If your hearing detonation unaided, that is a fair amount of force being applied in the wrong area.

It will not be an immediate failure but definitely will shorten engine life.

The sad thing is I could tune this issue away relatively easily, and have done so on the supercharged trucks I am working on. Unfortunately I think HP asks an arm and a leg for an unlocked ECM and tuner, and really this should be a free fix as it is a defect. At any rate offer is open of you all buy an unlocked ECM, I am willing to look at the data and supply a free calibration that fixes the issue.
 

ShadowsPapa

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Dave - please don't take this as arguing or disagreeing as your theories hold water, IMO - however, I'd like to clarify some things and see if we're using different words to get to the same places............

Oil may address the issued, if the cam phazer is not moving fast enough or correctly. A good flush and the correct weight synthetic, may just get it to stop.
If the dealer is doing the oil changes, or if the owner is, and is using the recommended oil - what more could be done? If using an oil that is heavier, or that doesn't score as well in film strength, etc. yeah, issues - but if it's the dealer and they are using the factory type oil........


My guess is this issue comes down to cam timing and ignition timing. The cam and cam phazer is set up in such a way, software or mechanically, that it is locking to much air into the cylinder at low load. It only happening when hot indicates this is probably a marginal tolerance stack up issue. Basically the heat is the differentiator that causes the quicker burn of the charge. That is a very thin margin of ignition.
Absolutely and this has been true since the beginning of either pre-ignition OR detonation. HEAT.
A cool engine won't detonate and there's no heat to cause the fuel to ignite before spark.
Compressing a gas causes it to get hot. Basic science.
If the starting point pf the gas you are compressing is 220 degrees then you add the heat of compressing it, you are more likely to reach self-ignition than if it's 100 degrees and you compress the same gas the same amount. You'd end up below the point of self-ignition.
That's an absolute given. I've solved detonation in many ways - getting the engine to run cooler was among those ways (talking old-school cars and trucks here).

The materials are stronger but lighter, not like older engines, they are not designed to take long term misfire. The rings are thin for fuel milage and will eventually crack or flutter out and acore a cylinder wall. Or you will fret the head gasket. This is an open deck motor.

If your hearing detonation unaided, that is a fair amount of force being applied in the wrong area.
First - the good - aluminum heads and blocks detonate a lot less easily than cast iron blocks. A lot of people have put aluminum Indy or Edelbrock heads on engines like in my cars and gotten rid of detonation simply because it's aluminum and the heat is controlled far better.

Ring flutter is an issue - it's been an issue for several decades but is a lot worse with the smaller profile of today's rings because they aren't as rigid. Cracked rings can be a bigger issue today because of the forces the vibrations cause vs. the smaller profile.

But - my question - force being applied to the wrong area? Isn't it all the same area? piston head, the small areas of the tops of the rings that are exposed to combustion pressures and forces? What wrong area? All forces are applied there..........

The issue is the strength of the force - and detonation means the forces are applied too fast. Since the burn is started well before the piston is at TDC, in a normal controlled burn the maximum pressures of combustion are achieved about 14 degrees ATDC even though the burn may start at, just as an example, 36 degrees BTDC - because the burn takes TIME. If there's something that lights the charge too fast, you have the pressures too high when the rod is still high and not down as a lever. You also have the forces of two flame fronts and the explosive forces of the two fronts colliding rather than a smooth controlled burn pushing when things are in the right position.
Maybe that's the meaning - so I'm asking.

At any rate - GM has resolved a lot of these issues with some really tricky, fancy, designs in the heads to prevent hot spots - I wonder if Jeep is facing some of the same issues GM did and hasn't addressed it in better head cooling.

The dynamic compression idea is one of the few that makes sense here. 11.3 is pushing the envelope as it is, add to that phasers that are raiding the dynamic compression too much and poor tuning................. Timing changes won't do a lot to help if the chamber is compressing too much gas to the point that it's hot enough to ignite fuel.
 

SelfmodJT

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Couple things. Oil may address the issued, if the cam phazer is not moving fast enough or correctly. A good flush and the correct weight synthetic, may just get it to stop.

The dealer does not want to address it because this is a bit complicated to do in a timely matter for your average mechanic.

My guess is this issue comes down to cam timing and ignition timing. The cam and cam phazer is set up in such a way, software or mechanically, that it is locking to much air into the cylinder at low load. It only happening when hot indicates this is probably a marginal tolerance stack up issue. Basically the heat is the differentiator that causes the quicker burn of the charge. That is a very thin margin of ignition.

Dealers do not have access to be able to recalibrate or tune and engine, they can only report to Chrysler/Jeep they suspect something is wrong, and then rhey have to depend on a service engineer to take their problem seriously and get the responsible team to release an update.

The dealer's direct options to fix the issues
1. Flush engine oil, replace with new and do a cam phazer cleaning cycle with the service tool
2. Replace the cam phazers on the engine.
3. Replace the camshafts on the engine
4. Replace the engine

Audible detonation in these new engines is not good. The compression is already high, and ot was designed as such, because it was given that the controls would eliminate all chances of that happening. The materials are stronger but lighter, not like older engines, they are not designed to take long term misfire. The rings are thin for fuel milage and will eventually crack or flutter out and acore a cylinder wall. Or you will fret the head gasket. This is an open deck motor.

If your hearing detonation unaided, that is a fair amount of force being applied in the wrong area.

It will not be an immediate failure but definitely will shorten engine life.

The sad thing is I could tune this issue away relatively easily, and have done so on the supercharged trucks I am working on. Unfortunately I think HP asks an arm and a leg for an unlocked ECM and tuner, and really this should be a free fix as it is a defect. At any rate offer is open of you all buy an unlocked ECM, I am willing to look at the data and supply a free calibration that fixes the issue.
I'm suprised this issue was never fixed for the 3.6 pentastar engine. It seems like the detonation has been an on going issue for many years if you google the problem. Are owners just accepting the answer that it's normal from the dealership and manual stating it's normal for the engine to ping? Maybe it's the luck of the draw with these engines, hopefully mine gets worse before my warranty is expired so I can force them to do something. I'm at 6k miles so 54k miles to go. I am switching back to 87 octane and not paying more for 93 octane to mask the problem because the manual also states to use 87 octane.
 

SelfmodJT

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Dave - please don't take this as arguing or disagreeing as your theories hold water, IMO - however, I'd like to clarify some things and see if we're using different words to get to the same places............



If the dealer is doing the oil changes, or if the owner is, and is using the recommended oil - what more could be done? If using an oil that is heavier, or that doesn't score as well in film strength, etc. yeah, issues - but if it's the dealer and they are using the factory type oil........




Absolutely and this has been true since the beginning of either pre-ignition OR detonation. HEAT.
A cool engine won't detonate and there's no heat to cause the fuel to ignite before spark.
Compressing a gas causes it to get hot. Basic science.
If the starting point pf the gas you are compressing is 220 degrees then you add the heat of compressing it, you are more likely to reach self-ignition than if it's 100 degrees and you compress the same gas the same amount. You'd end up below the point of self-ignition.
That's an absolute given. I've solved detonation in many ways - getting the engine to run cooler was among those ways (talking old-school cars and trucks here).



First - the good - aluminum heads and blocks detonate a lot less easily than cast iron blocks. A lot of people have put aluminum Indy or Edelbrock heads on engines like in my cars and gotten rid of detonation simply because it's aluminum and the heat is controlled far better.

Ring flutter is an issue - it's been an issue for several decades but is a lot worse with the smaller profile of today's rings because they aren't as rigid. Cracked rings can be a bigger issue today because of the forces the vibrations cause vs. the smaller profile.

But - my question - force being applied to the wrong area? Isn't it all the same area? piston head, the small areas of the tops of the rings that are exposed to combustion pressures and forces? What wrong area? All forces are applied there..........

The issue is the strength of the force - and detonation means the forces are applied too fast. Since the burn is started well before the piston is at TDC, in a normal controlled burn the maximum pressures of combustion are achieved about 14 degrees ATDC even though the burn may start at, just as an example, 36 degrees BTDC - because the burn takes TIME. If there's something that lights the charge too fast, you have the pressures too high when the rod is still high and not down as a lever. You also have the forces of two flame fronts and the explosive forces of the two fronts colliding rather than a smooth controlled burn pushing when things are in the right position.
Maybe that's the meaning - so I'm asking.

At any rate - GM has resolved a lot of these issues with some really tricky, fancy, designs in the heads to prevent hot spots - I wonder if Jeep is facing some of the same issues GM did and hasn't addressed it in better head cooling.

The dynamic compression idea is one of the few that makes sense here. 11.3 is pushing the envelope as it is, add to that phasers that are raiding the dynamic compression too much and poor tuning................. Timing changes won't do a lot to help if the chamber is compressing too much gas to the point that it's hot enough to ignite fuel.
So if the knock sensor senses the vibration and it cannot fix the pinging because it is not a timing issue why is it not setting off a check engine light? The vibration is obviously strong enough to resonate the sound to the transmission because the noise I hear is not from the front of my Jeep but rather from the middle of the Jeep.
 

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ShadowsPapa

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I wonder why so many do NOT ping. IF the majority did it, there'd be different findings. Yes, you can google it and get tons of results, but the internet is where people complain, not to report "hey, I have a Jeep that DOESN'T ping!"

Why some and not all?
Why do some say they run 91-93 octane and see no difference? (Dave's logic would fit those people quite well....... and the stack-up of tolerances theory of his also helps explain that one)
Why not mine - even though I tend to be the sort of driver that abuses engines? Maybe it's because I get pissed if the thing is in lugging range and push harder forcing a downshift - high RPMs tend to not ping.

So if the knock sensor senses the vibration and it cannot fix the pinging because it is not a timing issue why is it not setting off a check engine light? The vibration is obviously strong enough to resonate the sound to the transmission because the noise I hear is not from the front of my Jeep but rather from the middle of the Jeep.
Not all misfires or other anomalies set the MIL! My wife had a BAD BAD misfire to the point the thing was bucking like a bronco with a burr under the saddle - no MIL, no codes set. The MIL is not a catch-all.
 

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Dave - please don't take this as arguing or disagreeing as your theories hold water, IMO - however, I'd like to clarify some things and see if we're using different words to get to the same places............



If the dealer is doing the oil changes, or if the owner is, and is using the recommended oil - what more could be done? If using an oil that is heavier, or that doesn't score as well in film strength, etc. yeah, issues - but if it's the dealer and they are using the factory type oil........




Absolutely and this has been true since the beginning of either pre-ignition OR detonation. HEAT.
A cool engine won't detonate and there's no heat to cause the fuel to ignite before spark.
Compressing a gas causes it to get hot. Basic science.
If the starting point pf the gas you are compressing is 220 degrees then you add the heat of compressing it, you are more likely to reach self-ignition than if it's 100 degrees and you compress the same gas the same amount. You'd end up below the point of self-ignition.
That's an absolute given. I've solved detonation in many ways - getting the engine to run cooler was among those ways (talking old-school cars and trucks here).



First - the good - aluminum heads and blocks detonate a lot less easily than cast iron blocks. A lot of people have put aluminum Indy or Edelbrock heads on engines like in my cars and gotten rid of detonation simply because it's aluminum and the heat is controlled far better.

Ring flutter is an issue - it's been an issue for several decades but is a lot worse with the smaller profile of today's rings because they aren't as rigid. Cracked rings can be a bigger issue today because of the forces the vibrations cause vs. the smaller profile.

But - my question - force being applied to the wrong area? Isn't it all the same area? piston head, the small areas of the tops of the rings that are exposed to combustion pressures and forces? What wrong area? All forces are applied there..........

The issue is the strength of the force - and detonation means the forces are applied too fast. Since the burn is started well before the piston is at TDC, in a normal controlled burn the maximum pressures of combustion are achieved about 14 degrees ATDC even though the burn may start at, just as an example, 36 degrees BTDC - because the burn takes TIME. If there's something that lights the charge too fast, you have the pressures too high when the rod is still high and not down as a lever. You also have the forces of two flame fronts and the explosive forces of the two fronts colliding rather than a smooth controlled burn pushing when things are in the right position.
Maybe that's the meaning - so I'm asking.

At any rate - GM has resolved a lot of these issues with some really tricky, fancy, designs in the heads to prevent hot spots - I wonder if Jeep is facing some of the same issues GM did and hasn't addressed it in better head cooling.

The dynamic compression idea is one of the few that makes sense here. 11.3 is pushing the envelope as it is, add to that phasers that are raiding the dynamic compression too much and poor tuning................. Timing changes won't do a lot to help if the chamber is compressing too much gas to the point that it's hot enough to ignite fuel.
Oil changing and cleaning, I dont think will be a magic bullet. But there is a chance that dirt or breakin material, or materials from the phazer, could be jacking things up. The cleaning process exists for a reason.

As for force in the wrong places. To be clear I meant additional force be created by higher pressures from a burn happening at a place and time that was not expected or intended.

The timing is an interesting thing as there are tables related directly to the cams moving and repositioning . In all there is probably 9 tables it can pull values from. You could shut down timing
 

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So if the knock sensor senses the vibration and it cannot fix the pinging because it is not a timing issue why is it not setting off a check engine light? The vibration is obviously strong enough to resonate the sound to the transmission because the noise I hear is not from the front of my Jeep but rather from the middle of the Jeep.
The knock sensors are fixing the ping. The problem is they cannot fix it until they hear it. My WOW! Commwnt above is because the ping is significant enough it is audible to the human ear. So this event is very forceful and very fast, meaning that it happens within milliseconds all at once, audibly. That leads me back to the cams just being in the wrong position as the engine transitions. Doesn't set of a mill because the misfire light is looking for a longterm event to tell you an ignition component has failed, on top of that Jeep has dumbed down the mil dor misfires in a recent software and tab update cause everyone was getting the avengers light.
 

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'25 JTMX, '23 JLU 4xe, '82 SX4, '73 Javelin
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1. Oil changing and cleaning, I dont think will be a magic bullet. But there is a chance that dirt or breakin material, or materials from the phazer, could be jacking things up. The cleaning process exists for a reason.

2. As for force in the wrong places. To be clear I meant additional force be created by higher pressures from a burn happening at a place and time that was not expected or intended.

The timing is an interesting thing as there are tables related directly to the cams moving and repositioning . In all there is probably 9 tables it can pull values from. You could shut down timing
1. - 100% it should be done as a precaution in these cases because the clearance on these things is a gnat's eyelash. Like the shuttles and valves in an automatic, a piece smaller than my thin human hair can lock 'em up tight. A piece of lint - I don't mean a chunk, I mean 1 individual piece.
And your last sentence in what I've numbered as 1 in your quote - yes, absolutely. And this is a good candidate for running that process.

2. OK, we ARE in the same place there, just differently worded. There are "Two places" - one is a place in time and that's obviously wrong, the other is the place where the rod is in its travel (and thus the crankshaft and piston). I figured as much but wanted to be sure.

I can relate to the rest as building engines from the 60s-80s, you are doing the same things, just manually. (although centrifugal cam timing devices existed even 60 years ago).
Ignition timing has to change with RPM, A/F ratio, load on the engine, temperatures, pressures and other factors. If the cam phasers are not ending up where they should...........
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