Rattle from engine when accelerating (sounds like keys)

[SelfmodJT]

I'd expect a failing sensor to trigger errors - either transient or if consistent, enough to trigger a light.
Can't see a correlation with detonation - which is a timing/heat/pressure issue.
Lean burning causes overheating but that's more of an old-school issue with carburetors.

Well i guess the smell goes on the list, probably wont happen at the dealer but there def was a smell. Gald at only 6k miles, still 54k for on the warranty. I doubt its running lean, has to be running rich because my mpg sucks really bad. If its running rich wouldnt that cause a cat to go bad quickly?

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[casualthursday]

Update from my 2nd visit to the dealer:

I dropped off my truck on Monday morning for an additional tech to diagnose the rattle. I got a call back late afternoon from the service advisor that the tech was able to recreate the noise. They asked to keep the Jeep overnight to open a STARS case.

I'm not sure the purpose of the STARS case, I picked up the Jeep Tuesday afternoon and there was no mention of it. Unfortunately, both of my work orders say the vehicle is operating normally. I was advised to give the Jeep 500 more RPMs before shifting.... and to try running a higher octane fuel.

I'm due for a fillup tonight, I'll make the jump from 87 to 89 and report back.

We are also going on vacation next week where it's generally 15 degrees cooler. Interested to see how that might change how the Jeep acts.

 

[SelfmodJT]

Update from my 2nd visit to the dealer:

I dropped off my truck on Monday morning for an additional tech to diagnose the rattle. I got a call back late afternoon from the service advisor that the tech was able to recreate the noise. They asked to keep the Jeep overnight to open a STARS case.

I'm not sure the purpose of the STARS case, I picked up the Jeep Tuesday afternoon and there was no mention of it. Unfortunately, both of my work orders say the vehicle is operating normally. I was advised to give the Jeep 500 more RPMs before shifting.... and to try running a higher octane fuel.

I'm due for a fillup tonight, I'll make the jump from 87 to 89 and report back.

We are also going on vacation next week where it's generally 15 degrees cooler. Interested to see how that might change how the Jeep acts.

How long did they drive the jeep before they said its operating normally? It usually takes about 15 mins for the engine to reach operating temperature, on mine it's dead silent before it reaches operating temperature. Another question, just out of curiosity do you baby the engine? By that I mean what's the highest rpm you have driven it so so and at what rpms do you normally shift?

 

[SelfmodJT]

In response to using the higher octane, yes it may help but it seems like that would be a band aid on the problem. Why are they saying to use 89 or 93 if the manual says the engine is rated for 87 and to use 87? If they tell me that I'm going to say the manual says to use 87 so im going to use 87 if it gets worse then it's a good thing so they address the problem, correct?

 

[casualthursday]

I don't drive aggressively and I try to be mindful of how much fuel I'm using, so I generally shift around 3k..... which puts me around 2k on the next gear. This is also dependent on how quickly I need to get to a certain speed (more RPMs for quicker acceleration). But yes, to answer your question, I guess I do baby the engine.

 

[DAVECS1]

The programming does have high and low octane tables, sam goes for cam timing and ahift points. Not sure why they tell everyone 87 is good enough. Highwr ovtane is not a band-aid. It will activate better maps in the software

 

[ShadowsPapa]

My take, for what it's worth (likely every penny you paid for it) - yes on shifting, bunk on octane just on principal.
Could it help? It COULD - maybe - but you bought a truck that is advertised in all the books, owner manual and other places- 87 octane. It clearly states use 87.
Mine does NOT ping on 87. Everything works as it should meaning that the valve lift, valve timing, spark timing and other things are falling into place to deal with 87 octane fuel. Most of the other 3.6s do as well. My wife has owned multiple Jeeps with 3.6 Granted, a very different tune in a JT vs a WK2, but still a 3.6
To suggest a customer ignore the owner manual and "fix" a problem by using more expensive fuel than what the BOOKS say baffles me. If it can't run on 87 then they are lying (or that engine has an issue)

I should post a snippet from a book or two I have that explains a few things about "lugging" and the side effects (including detonation) it might support the shifting sooner thing.

 

[ShadowsPapa]

The programming does have high and low octane tables, sam goes for cam timing and ahift points. Not sure why they tell everyone 87 is good enough. Highwr ovtane is not a band-aid. It will activate better maps in the software

Yes, it should - but they DO advertise to use 87, it's in the book, don't they even say anything more is not necessary and won't help?
So they either need to totally change all of their documentation, bulletins and other communications including the owner manual, or fix the engine so it doesn't ping on 87.
Mine doesn't, most don't, so IMO, those that do likely have a problem.

On another point, I see many of these are manual transmissions - making me wonder if shifting is happening too soon.

I've also seen where others have said they've tried 91 and 93 and it didn't seem to help - that suggests that those engines have something physically wrong (phasers hanging up, not responding quickly enough?)
The valve lift and opening and closing points are all over the planet on these things - so if something isn't working exactly right, things could go south quickly.

Mine does not ping on 87, even if I try to make it happen. So obviously, the "cheap" mapping works - usually. Is it ideal? It works, and most get by just fine on 87 without ping and don't complain about power output.

That's my point on it - it's advertised, it's sold that way, and most of us can and do run 87 with no bad results, no ping and power ok.
A person can choose to use higher octane - but that shouldn't be a solution for engine troubles with 87 (especially when higher octane doesn't always resolve it)

 

[DAVECS1]

I dont disagree they advertise it it to run that way, and at the end of the day, they should make right. I think the manual transmission has a couple of complications with their current tunning. 1. They cannot transition the fuel as quickly as they can in an automatic. I assume they are delaying to see what the operator does with the load. 2 the cam tables are based on the torque model, there is probably a transport delay, from the caluclated torque demand to the time it moves the cams, that ahould and can be tuned out but not by the dealer.

Once again I agree. But if you run higher octane it could get you around these calibration issues. Unless people actually do have a mechanical issue

 

[ShadowsPapa]

I dont disagree they advertise it it to run that way, and at the end of the day, they should make right. I think the manual transmission has a couple of complications with their current tunning. 1. They cannot transition the fuel as quickly as they can in an automatic. I assume they are delaying to see what the operator does with the load. 2 the cam tables are based on the torque model, there is probably a transport delay, from the caluclated torque demand to the time it moves the cams, that ahould and can be tuned out but not by the dealer.

Once again I agree. But if you run higher octane it could get you around these calibration issues. Unless people actually do have a mechanical issue

We're on the same page I'm sure.
For me - it's a Jeep issue - jeep engineered it this way, they market and sell it this way, make it work.
Maybe for some - it's a matter of not babying the engine - wind it up a bit more before shifting.

And that brings up a question - these don't do a decel fuel shut off do they (can't recall the exact term - got other stuff going on) during shifting of a manual transmission?
Don't these detect the clutch being depressed and skip the decel fuel stop or whatever?

 

[DAVECS1]

They look at calculated torque load to do controlled throttle shifting, and I think this is part of the tolerance stack up that causes issues

 

[Higher_Ground]

This is all extremely interesting but mostly over my head. I do know that those of us experiencing it in an automatic can't control the RPMs at which the transmission shifts and it seems like 100% of the time that it happens when I'm coming off a deceleration I couldn't avoid.

Thankfully I don't have the same situation where I'm hitting half a dozen speed bumps in the road and it was intermittent enough that I'm currently pretending like it never happened.

Still, should one of y'all find a solution I want to test it out and see if it helps.

 

[reverse01134]

Update from my 2nd visit to the dealer:

I dropped off my truck on Monday morning for an additional tech to diagnose the rattle. I got a call back late afternoon from the service advisor that the tech was able to recreate the noise. They asked to keep the Jeep overnight to open a STARS case.

I'm not sure the purpose of the STARS case, I picked up the Jeep Tuesday afternoon and there was no mention of it. Unfortunately, both of my work orders say the vehicle is operating normally. I was advised to give the Jeep 500 more RPMs before shifting.... and to try running a higher octane fuel.

I'm due for a fillup tonight, I'll make the jump from 87 to 89 and report back.

We are also going on vacation next week where it's generally 15 degrees cooler. Interested to see how that might change how the Jeep acts.

Well that's disappointing. Mine is automatic and I am curious what the dealership will say. Always put in manual mode and shift at a higher RPM? lol

I don't agree running higher octane fuel should be an answer. It may reduce/eliminate the noise but who knows if the problem is still there and it's slowly killing the engine?

 

[ShadowsPapa]

 

[SelfmodJT]

I stopped running at low rpms awhile ago, I try to stay above 2k rpms at any moment if possible. But it still pings on 87 in the 2k to 3k rpm range, I've even noticed it going down hill now when I'm giving it gas. I think something is making my jeep run rich? Maybe that's what's causing the detonation and the smell from the exhaust.

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