My 4.7 sometimes idles at 600rpm or 700rpm then theres sometimes where it idles at 500rpms and shakes the whole truck any ideas what this could be?

most of the time i notice this when its in drive sitting at a stoplight

 

Ive had that issue to....cleaned out the idle air control valve, pretty sure thats the name of it (that little slot of the bottom of the main throttle body bore) and now it doesnt really vibrate anymore. Stays around 650....drops to 550 every once in awhile but I cant really feel vibration anymore. From what I've found a lot of 3rd gens have this issue and cleaning the TB usually helps.

 

My truck idles in the 650 range except when I'm at a stoplight it drops to 500 as long as the A/C is off. The doesn't shake when it idles low though. I think the IAC is the cause as mopar said above.

 

Mines around 600 usually. Except the random start once a month where it falls flat on its *** and takes a second to pick up.

 

I think its been as low as 400. But mostly 500 ish

 

Mine idles at 500 after warmed up.

The only odd thing is a rare "almost stall", but before it can stall, it kicks itself back up and idles at 600 for a little bit after that. Only seems to happen when the ambient temp is 68-74 according to the overhead. But not everyday, maybe twice each spring and fall.

Any other temps and it doesn't flinch. AC kicks the RPM to 600.

 

mine idles at 600 most of the time, sometime when i stop and throw into park itll shoot upo to 1k and hang there, i just tep the pedal a lil and it goes back down, prolly something to do with my ported and polished throttle body, not enough to worry me...

 

ok i see that the 500 idle is normal but answer me this when i first start the truck in the morning doesnt matter if its 60 degrees or 30 degrees out itll start the high idle then drop down for a second then go right back up so within ill say 3 seconds from starting itll go from 1500rpm to 700rpm then back up to 1500rpm somtimes itll go up and down like that just once sometimes itll do it 2 or 3 times is that normal?

final question.. when shifting into reverse i ALWAYS get this grinding noise and sometimes itll act like its just in neutral and not even go anywhere but still shows its in reverse on the selector then sometimes itll go then kick its self out of gear and not even show being in any gear on the selector but from park to drive or any other gear there is no noise only when i shift into reverse doesnt matter from which gear it ALWAYS has this grinding noise is this normal?

ok seriously last question.. not only does it grind going into reverse it ALWAYS has a big clunk when shifting into park doesnt matter from what gear when shifting into park it ALWAYS goes clunk drives me nuts what could cause that?

 

Mine doesnt really make a noise, but it kinda jumps. Like the suspension torques up from shifting from neutral to drive. Nothing wrong with it. Its always made a slight noise when it shifted gears. If yours is making a clunk I would check your u joints.

Oh and the high idle kicks on always unless its super hot out and stays around a 1000 rpms. A slight touch of the pedal and it'll stop.

 

Mine will make the reverse grind noise only when it has not been started for a few hours (overnight/after work).

Had the Ram in for repair and the service writer told me that it is known and considered normal and there is no answer for it right now.

Told him it was embarrassing to have that happen, especially when parked next to a Chevy or Ford and have that happen when the other owner is standing nearby.