Rattle from engine when accelerating (sounds like keys)

[Scrubb84]

Ok, i hope this works for a few of you guys. My jeep runs almost perfect now, of course if it lugs on a steep incline it will still have detonation. If you baby your engine, STOP. Also, have you guys that are having this issue done a wide open throttle on the highway yet? If not, DO IT. Obviously im not knowledgeable and experienced as some if not most on this forum but i can turn a wrench lol. After viewing and researching the 3.6 pentastar engine, what causes detonation, etc i decided to do a few wide open throttles on the highway. I did a few in 3rd gear and 4th gear reaching 5.5k to 6k rpms. After the 2 or 3 i noticed a considerable difference, so i did about 10 within a few days. So today i had no dentonation!!! And it was almost 100 degrees here in PA and i went on almost all the inclines in my area in 2nd gear with the starting rpms at 1.5k and no pinging!!! So i will let you know that i was running 93 octane because thats what i filled up last with because thats what people said to do. It helped initally, but after about a quater tank it was back to normal pinging. I finally burned all the 93 to about only a quater tank left and just filled it up with 87 octane and went back on all the inclines. NO DETONATION!!! I believe babying the engine and trying to drive the jeep in the lowest rpms to conserve gas made it run a little rich because the throttle was barely opened and never wide open. I think this may have caused a carbon build up and causing the pinging and also getting to my cat causing the sulfer smell. Again, im no expert or claim to be lol but it worked for me!! I believe the wide open throttles got rid of the carbon build up?

Please give an update in about a week. I came across this exact same thing (minus the wide open driving) a few weeks ago. I ran all the 93 out the day before my last service appt just for this detonation noise issue and filled up with 87 thinking the noise would be so loud they couldn’t deny it this time. Well it turns out that as soon as you go back to 87 it doesn’t make any det sound for about 5 days. This was the case for me at least, and your post just confirmed I’m not going crazy, as it pertains to this case anyways. Lol.
Day 6 of back to 87 & the det came back strong as ever.

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[SelfmodJT]

A couple of years ago, investigating the JT and even trying to learn more about the 3.6 in my wife's recent string of Grand Cherokees, I ran across a couple of things out there - can't recall where, but a couple of long-time 3.6 owners both said "these engines need to be wound up now and then" meaning take them out and romp them, get into the higher RPM ranges and make them work at high RPM.

I've always done with with everything I've owned. Usually it's because that's just me, how I drive, and maybe it's partly because I was taught by old-timers that engines can build up deposits and varnishes on parts that if later pushed, ends up moving outside of the range of "normal travel" for that driver and engine and then things get into those deposits, that "varnish" and stick, or can't move as far as they should.

I remember you and the other guy talking about phasers and the timing. I dont think I ever drove the jeep hard enough to even engage the VVT on the higher end lol. Maybe going to 6k rpms knocked the kinks out.

 

[DAVECS1]

There are aggression maps that alter timing and torque demand, shift points on automatics. You elevated the aggression counter, and started using different maps.

 

[SelfmodJT]

Please give an update in about a week. I came across this exact same thing (minus the wide open driving) a few weeks ago. I ran all the 93 out the day before my last service appt just for this detonation noise issue and filled up with 87 thinking the noise would be so loud they couldn’t deny it this time. Well it turns out that as soon as you go back to 87 it doesn’t make any det sound for about 5 days. This was the case for me at least, and your post just confirmed I’m not going crazy, as it pertains to this case anyways. Lol.
Day 6 of back to 87 & the det came back strong as ever.

Hmmm, mine was still pinging on 93 till I did the wide open throttles.

 

[ShadowsPapa]

There are aggression maps that alter timing and torque demand, shift points on automatics. You elevated the aggression counter, and started using different maps.

I only WISH my shift points would change. They are CRAP. These things shift like my grandmother's Rambler. Too early, way too conservative, keeping the RPM waaay down. Mine wants 8th gear no matter what, stays there for a few seconds, then I see it's in 6th or even 5th just to keep speed limit on a hill.
I like the transmission well enough, but the constant need for it to be in 8th for a few seconds before shifting down again just really stinks.

 

[Scrubb84]

Hmmm, mine was still pinging on 93 till I did the wide open throttles.

I would love it if your success in this matter continues, I’m just sharing and comparing data/info.

 

[ShadowsPapa]

Please give an update in about a week. I came across this exact same thing (minus the wide open driving) a few weeks ago. I ran all the 93 out the day before my last service appt just for this detonation noise issue and filled up with 87 thinking the noise would be so loud they couldn’t deny it this time. Well it turns out that as soon as you go back to 87 it doesn’t make any det sound for about 5 days. This was the case for me at least, and your post just confirmed I’m not going crazy, as it pertains to this case anyways. Lol.
Day 6 of back to 87 & the det came back strong as ever.

Dave can speak to this I bet - long term vs short term fuel trim I think are the terms? Things take time to happen.

 

[SelfmodJT]

Only helped a little when I initially switch to 93 for about a quater t

There are aggression maps that alter timing and torque demand, shift points on automatics. You elevated the aggression counter, and started using different maps.

Whatever it did I hope it resolved the issue. I really didnt want the dealer taking everything apart and telling me it's normal. I'm still going tomorrow for them to do the clutch software recall and hopefully my exhaust will still emit a smell so theyll look into that.

 

[SelfmodJT]

I would love it if your success in this matter continues, I’m just sharing and comparing data/info.

I will keep this thread updated. If you havent tried a wide open throttle, try it a few times. What do you have to lose? I remember the Rx 8 with a rotary engine you had to do wide open throttles regularly to clean out the carbon or the engine would not run right.

 

[MPMB]

With the doors on, I don't really hear anything.

Doors off, coming up my hill home when I goose it a little - less than 1/4 throttle, sounds like I got someone collecting for The Human Fund or UNICEF under my truck. But just for less than a second.

 

[DAVECS1]

I only WISH my shift points would change. They are CRAP. These things shift like my grandmother's Rambler. Too early, way too conservative, keeping the RPM waaay down. Mine wants 8th gear no matter what, stays there for a few seconds, then I see it's in 6th or even 5th just to keep speed limit on a hill.
I like the transmission well enough, but the constant need for it to be in 8th for a few seconds before shifting down again just really stinks.

The transmission tuning is lack luster for sure. I have made 241 changes to the shift schedule and 128 changes to the trans torque model and it is almost where I want it. All that work to keep part throttle operation around 2000 rpm. Used to be you could tell it the engine rpm you wanted to shift at, and done. Now there are enough tables to make Einstein scratch his head and ass at the sametime.

 

[ShadowsPapa]

I will keep this thread updated. If you havent tried a wide open throttle, try it a few times. What do you have to lose? I remember the Rx 8 with a rotary engine you had to do wide open throttles regularly to clean out the carbon or the engine would not run right.

I remember the first time I did a tune-up on one of those little engines. The owner was the son of the guy who owned the AMC dealership - which the shop I worked in was part of. The guy was also a friend. I opened the hood and - ok, where's the engine? Oh, look, two plugs per rotor, a leading and trailing spark plug. The tune-up was easy except for the fuel filter location. Took me time to find it. (as I recall, in the trunk under a panel.......)

 

[Scrubb84]

I will keep this thread updated. If you havent tried a wide open throttle, try it a few times. What do you have to lose? I remember the Rx 8 with a rotary engine you had to do wide open throttles regularly to clean out the carbon or the engine would not run right.

Got a speeding ticket the other day when i was passing someone, so yes, on occasion i will “give her the beans”. Lmfao. But what scares me is how did u know i used to own an rx8?

 

[SelfmodJT]

So I'm at the dealer and I'm going through all the issues i was having and the guy behind the counter asks me what octane i use lol. I said, " 87 is the lowest right and that is what is recommended in the manual, right? " i can see where this going... and then i tell him about the rotten egg smell and he looks at me like im crazy cause its a new jeep. I drove 60 miles for this? It didnt smell and it passed emissions so what can I make them do??? They said to use a different gas station because the quality of the gas could be different even though it's a top tier gas station. Idc anymore at this point as long as the engine doesnt start pinging again. The cat warranty is 8yrs or 80k miles which he confirmed.

Anyways, since I've been wide open throttling I've noticed this engine is shit after 75 to 80mph range lol. Wide open in 4th gear and it barely accelerates when I'm over 80. I just googled the top speed and it said 97. Maybe downhill and if I make a ski helmet big enough for the front end then maybe 97mph. Anyone hit 97mph?????

 

[SelfmodJT]

Also, since driving the jeep in the higher rev ranges now, I feel like I'm driving a go cart. Maybe its because im getting desensitized to the torque in the med rev ranges but it absolutely feels like a go cart now.

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