rough idle and trans

[rdmac]

Anybody have these problems. When you put the car in reverse it makes a thunk sound. When you do this for the first time in the morning the car makes the thunk and lurches backwords a bit (even after you let it idle a minute). Also at times there are some hard shift changes when going forward. Last but not least the car idles rough. The dealer doesn't notice anything or says its normal.

Bob

[DMAG]

Sounds like something with the trans. Does the trans slip at all when shifting? (That's what it sounds like its doing in reverse)

Get a second opinion at another dealer if you can't get any satisfaction at your current one.

[Motorpsycho]

I get the same thing in my Magnum R/T. I thought maybe it was just because my driveway is on an incline to the rear and the driveline torques up angainst the trans gear stop (pall?). Haven't noticed it on level ground yet.

[rdmac]

My driveway is on an incline also. Hasn't happenned anywhere else. No car I ever had before did this though.

[Greeneyej]

My 300C does this as well. The "thunk" but I'lm not worried.

[rcktpwrd]

My driveway is on an incline also. Hasn't happenned anywhere else. No car I ever had before did this though.

try setting the parking brake before letting off the regular brake when you park... especially on an incline... this will allow the brakes to hold the weight of the car and not the parking pawl in the trans... see if that helps any...

[JJS]

Last but not least the car idles rough. The dealer doesn't notice anything or says its normal.

Bob

I felt that as well a bit during a test drive. Considering the performance of the engine, I would imagine it is just camshaft 'lope'.

Just one of many websites that describe this...

http://www.autospeed.com.au/cms/A_0762/P_2/article.html

[snickle]

On of the reviews I read commented that getting that much power FROM a pushrod engine requires a warm cam, so the idle is a little rough. Though they comment you forget quickly when you step on the pedal.

[rcktpwrd]

I would aslo say the 'rough' idle may just be the 'bigger' cam.... (without actualy sitting in your car and feeling it) but there could be something else going on...
If you haven't had a big V8 in a long time, you just might be used to the very smooth idle of an overhead cam, 4 valve, 4 or 6 cylinder engine and not the 'lumpy' cam of a pushrod V8...

[Motorpsycho]

I've noticed the lumpy idle to. I have driven muscle cras in the past that had "lumpy cams" but this is more like a computer or vacuum leak. It isn'tthe same everytime and will "surge" while sitting at a light. Ithink something may be wrong, but I'm gunna waittill I run some better gas through it to see. It may just be something left over FROM manufacturing that will pass. If it is still lumpy when teh first oil change is due, I'll have them look INTO it.

[CDG]

I have driven a hemi ram and I can say its the cam but it will smooth out with some miles. My 96 Ram was the same way with 5.2 V8.

[Greeneyej]

Its the "warm cam" in the Hemi..

[JJS]

http://www.caranddriver.com/article....rticle_id=8009

Page 2...

"Pulling that much sauce FROM pushrods requires a warm cam, and the 300C shivers noticeably at idle."

[rdmac]

Well took it back to the dealer for a second time. They replaced the PCN on a recall and said that should solve things. Ran great for two days. Now back to surging in reverse at first start up in the day and rough idle and shifts. "Motorpsycho" how did you fair.

Bob

[360R/T]

Finding the same issue on our Hemi C. Huge "thunk" when putting INTO reverse and it almost seems like it wants to die when cold. Haven't taken it in to the stealership yet. Definatly curious as to what you all find.