[UK Commander]

Hi All,

I’ve had my 5.7 Hemi for a couple of months now with a total of 4,000 miles on the clock. However, when I turn the key to start her up (either cold, warm or Hot), the rev’s run high at about 1,500rpm and when I move from park to drive or reverse the revs drop to normal and I hear the sound of binding and popping from the transmission as she moves into the desired selection. This happens evey time I start her up!!!

Is this normal as my dealer says it is….but I don’t think so….

So…what does the font of knowledge say??? :bowdown:

 

[Ahmed]

I have the same problem but only when I put in reverse and its been there since new.

The dealer said the same thing as yours, its normal. but I'm still not convinced !!! it doesn't look normal at all !!

I will change the transmission and transfer case oils today and see if that will make any change and I will check the old oil if it has alot of metal wear.


UKCommander, that should be good news for you as its not only you having such problem, not like the other CDR transmission which you replaced three times !!

 

[robby]

UK and Ahmed,
Based on your description I also would consider this normal.
On a cold start or warm restart the computer is in open loop mode.
This means, it is in base[ fixed ] program. It will not go into closed loop [ecm control] untill a series of parameters are met.
The ecm is looking for, Coolant temperature. There is a pre-determined temp before ecm control can occur.
It is also looking for O2 sensor info so it can determine if exaust temp requirement has been met.
The ecm has turned on a electric air pump to speed up EGT [O2] warmup.
It has RAISED the idle speed to achieve the previous parameters as rapidly as possible.
If you put the vehicle in gear at startup with no warm time, the ecm will start to drop the idle speed to reduce the engagement shock, but it cant do it fast enouph.
The momemtum of the rotating parts conspires against rapid rpm drop, so, you create shift shock[ clunk ], Which is the rapid takeup of every components free play in the entire driveline.
Moral of the story, Wait till rpm drops to about 1000 rpm before putting in gear.
It only takes 30 to 90 seconds.
I usually put my belt on after I start it to let idle start to slow down.
To prove my point, right foot on gas/ hold 1500 rpm.
Left foot firmly on brake [no park brake] put it in gear. You will reproduce the driveline shock every time.
There is nothing wrong with the vehicle if my interpetation of the question is correct.

............Rob

 

[Ahmed]

Thanks robby, its not really a shock in the drive line, but rather ringing sound or as UKcommander said popping sound, I will try to record the sound and post here to hear it.

I know the shock is normal due to the high RPM, but that sound is different!

 

[robby]

Ahmed,
That sound is likely the audible ping that resonates through a hollow driveshaft on high rpm engagement shock.
I am fairly confident I've done it to myself when in a hurry.
Then I visualize all those components going, SMACK!
So, I don't rush it anymore.
.....Rob

 

[JJSEBASTIAN]

I don't think my idle ever is that high....
I don't remember this happening in mine. EVER. Even last winter with sub-zero temps.

 

[Get Lost 4X4]

my 4.7 does the same thing. if you wait 30 seconds it will drop the rev's and then it won't slam the transmission.

i think its normal.

Hi All,

I’ve had my 5.7 Hemi for a couple of months now with a total of 4,000 miles on the clock. However, when I turn the key to start her up (either cold, warm or Hot), the rev’s run high at about 1,500rpm and when I move from park to drive or reverse the revs drop to normal and I hear the sound of binding and popping from the transmission as she moves into the desired selection. This happens evey time I start her up!!!

Is this normal as my dealer says it is….but I don’t think so….

So…what does the font of knowledge say??? :bowdown:

 

[Ahmed]

I managed to record the sound, its in the attachment.

the sound occurs seconds after engine starts.

I used to neglect this as the dealer said its normal, I hope I didn't break something after 8 months and 20k miles.

 

[jeep5253]

Mine does not do it.

 

[Ahmed]

UKCommander, is it the same you hear in yours?

 

[JJSEBASTIAN]

Maybe I just wait after I start it in the winter.... I'll pay attention. Winter is commin!!

 

[UK Commander]

UKCommander, is the same you hear in yours?

Ahmed,

Yep, mine is the same sound...but when I bought the car It didnt make this sound nor did it rev high hence my concern.

The noise is there always during gear selection...have I got another duffer?

Maybe I just care for my XH tooooooo much!

I'll get some pic's up soon, just fitted her with some 265/45/20 rims and rubber!!!

 

[Ahmed]

I managed to record the sound, its in the attachment.

the sound occurs seconds after engine starts.

I used to neglect this as the dealer said its normal, I hope I didn't break something after 8 months and 20k miles.

Robby, did you manage to hear the sound which I recorded? I really would like to know what you think about? and whither I should worry about something that could happened to the transmission after 8 months? as I didn't used to wait for the RPM to get lower!

You can find the sound file attached to my post in the 1st page of this thread

 

[robby]

Hey Ahmed,
I listened to it today and I'm going to say, Inconclusive.
I did not hear any particular sound that raised concern, so, I still think its just driveline free play taking up.
I believe, if there was anything abnormally loose or out of spec. it would make odd engagement sounds regardless of rpm.

So,thats the best I can give from the other side of the world,
Rob

 

[Ahmed]

Hey Ahmed,
I listened to it today and I'm going to say, Inconclusive.
I did not hear any particular sound that raised concern, so, I still think its just driveline free play taking up.
I believe, if there was anything abnormally loose or out of spec. it would make odd engagement sounds regardless of rpm.

So,thats the best I can give from the other side of the world,
Rob

Thanks Rob,

I was a bit worried that it is sound of gears snatching each other and getting damaged. from now on I will comedown and wait till the RPM settle down and then shift it

 

[CrzCajun]

Do not have this problem on my 5.7L during winter or summer.

 

[jeep5253]

Thanks robby, its not really a shock in the drive line, but rather ringing sound or as UKcommander said popping sound, I will try to record the sound and post here to hear it.

I know the shock is normal due to the high RPM, but that sound is different!

Ahmed, check out this TSB. It may be the solution to the ringing sound.
03-004-07

 

[Ahmed]

Ahmed, check out this TSB. It may be the solution to the ringing sound.
03-004-07

I considered this TSP some time ago and prepared to take it to the dealer, but then I noticed this note in it ...

[NOTE: This bulletin only applies to RWD vehicles equipped with NAG1 transmission (W5A580, sales code DGJ).]

so its only for 2WD Commander.

Thanks

 

[jeep5253]

I considered this TSP some time ago and prepared to take it to the dealer, but then I noticed this note in it ...

[NOTE: This bulletin only applies to RWD vehicles equipped with NAG1 transmission (W5A580, sales code DGJ).]

so its only for 2WD Commander.

Thanks

Yes, I read that in the bulletin but it descibes a ringing like you described so it wouldn't hurt to get it checked out. It may be that it is happening to more than just the rear wheel drive vehicles and they don't know it yet.

 

[Ahmed]

Yes, I read that in the bulletin but it descibes a ringing like you described so it wouldn't hurt to get it checked out. It may be that it is happening to more than just the rear wheel drive vehicles and they don't know it yet.

Sounds good,, I will give it a try