at idle has a weird vibration

edcalli · 02-16-2012, 06:26 AM

The vibration can be felt throughout the hole vehicle it kind of seems like a low idle because if u press the gas a little it goes away. The idle is btw 500 and 750rpm.it doesnt do it at cold start up when rpms are higher

squazz · 02-16-2012, 07:00 AM

if it aint missing I would start by checking the motor mounts and transmission mount as well

jnowak · 02-16-2012, 07:25 AM

Mine does the same. About 1k smooths right up. But at idle all the windows and plastic shake

speedbucket · 02-16-2012, 09:17 AM

Clean your throttle body and IAC

edcalli · 02-16-2012, 10:52 AM

Quote:

Originally Posted by speedbucket

Clean your throttle body and IAC

i'll try cleaning throttle body and iac thanks 4 advice.

hdrocknroll · 02-16-2012, 04:03 PM

Quote:

Originally Posted by squazz

if it aint missing I would start by checking the motor mounts and transmission mount as well

Mine to
So !! how do you go about checking the motor mounts and transmission mount.
already cleaned throttle body and IAC, new crank sens, o2 sens,full tune up.
Is the transmission involved in the equation ,when in park ?
Edit: Mostly only doing it in gear.
Only vibration in neutral or park is a little when engine is brought up to 1500 rpm at 2000 it goes away

mikethefisher · 02-16-2012, 05:47 PM

mine has the same vibrating syptoms, in drive and park. it vibrates more in drive but when you put it in neutral the vibrating starts.

hdrocknroll · 02-17-2012, 01:42 PM

Any one else ,like to chime in here?
It would be greatly appreciated

jnowak · 02-17-2012, 04:47 PM

I have done all the approiate cleaning and tune ups. I am leaning toward engine mounts only thing i havent check

4Slow9erHybrid · 02-17-2012, 04:57 PM

It's a common complaint for the 4.0L ZJs. There's no definitive solution. Keeping the IAC clean, tune up helps but doesn't get rid of it. I replaced 1 engine mount and the tranny mount with no change. The new Anchor driver's side mount was defective, hence could not change it.

cdaniels85 · 02-17-2012, 05:24 PM

I'm in this boat as well. Misery loves company.

hdrocknroll · 02-18-2012, 04:54 AM

Could this be something like torque converter, or trans related ?

cdaniels85 · 02-18-2012, 10:14 AM

Quote:

Originally Posted by hdrocknroll

Could this be something like torque converter, or trans related ?

I first thought the same thing, then I had my tranny looked at and was told it is in great working order. I think it's mostly a combination of an inline engine and worn mounts. The mounts don't appear to be shot, but I think it just takes a little wear and the nature of this beast takes over.

hdrocknroll · 02-18-2012, 03:36 PM

Well !! It Doesn't look to hard to replace the three mounts.
Not expensive, I can get all three for 60 bucks.
I will take a look at them, and see what I can see. I don't know what else it could be.
After I replace them ,I will let you all know if it helped or not.

hdrocknroll · 02-20-2012, 05:37 PM

Well, my motor mounts were shot.
Replaced them today and dudes, it's running smooth. Now, only a very very slight vibration but I haven't done the trans mount yet.
The difference is like night and day. I don't know if this is everyone's problem with the shaking, vibrating, but it sure was mine.
The left one that I didn't take a picture of was a little worse than the one in the pic.
If yours are as bad as mine were, all you have to do is reach down there, and and see if you can stick your finger through it, if you can its shot.
You can see the old one is even separated at the bottom.
I put it in the snow so you could see the separation.
The second pic is not very good but the new one is on the left.