Rough Idle (when AC is on)

MikeE024

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Supporting Member
Joined
Mar 29, 2021
Messages
2,252
Location
Tucson
Vehicle: 2005 4.0L (auto)

The engine vibrations are pretty bad when idling under load. The vibes are gone once I raise the RPMs or drive the vehicle.

Youtube Video
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Things I have serviced or replaced:
- replaced spark plugs (Autolite XP985)
- replaced 02 sensors (NTK/NGK)
- cleaned the throttle body
- cleaned IACV
- replaced IACV (mopar)
- replaced TPS (mopar)
- replaced camshaft sensor (Napa Echelon)
- 1.25" MML using Mopar mounts

I read that the MAP sensor can cause this problem on other vehicles. Does anyone know what the MAP reading should be?
 
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Any resolution on your vibration? I too also have vibration at idle and gets a little more pronounced when the AC compressor kicks on and then goes undetectedwith higher idle. Started after tummy tuck, bbl,mml install. I've looked things coupled from engine to body but haven't found anything yet.
 
Any resolution on your vibration? I too also have vibration at idle and gets a little more pronounced when the AC compressor kicks on and then goes undetectedwith higher idle. Started after tummy tuck, bbl,mml install. I've looked things coupled from engine to body but haven't found anything yet.

Unfortunately, the vibrations seem to randomly come and go at this point. However, they are better than they used to be.

Things I've done since my original post:
  • Cleaned up my ground connections
  • cleaned up my alternator connections
  • changed my CPS (for a P0344 code), which instantly reduced vibrations.
In an attempt to help out I'll ask a few questions:
  • Are you sure that your transmission/xfr case are not touching the tub or exhaust?
    • My exhaust is very close to my transmission pan.
  • Are you using stock engine mounts? (that's the way to go)
  • What brand Tummy Tuck did you go with? (are you using the stock transmission mount?)
  • Are you using Mopar sensors?
 
As far as I've been able to tell it doesn't look like transmission or transfer case is hitting anything.

I'm using mopar motor mount.

Savvy tummy tuck

Haven't changed sensors so assuming they are tlstill mopar stock.

Thanks for reply.
 
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