rough idle

chaby_91

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For a while now I have had a shaky idle and I'm getting out of ideas to fix it.

No CEL
no stalling
MPG is good
power is good
spark plugs are good
IACV clean
EGR passage clean
coolant bled
valve lash adjusted


engine idles at 750 rpm
shakes up to 1k rpm then smoothes out.
A/C at idle makes it much worse
rear defrost also makes it vibrate more
-» high electrical demand

I'll provide any additional info.
Ty
 
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xci.ed6

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Prolly a vac leak, check what your computer sees, Torque for bluetooth obd2 adapters works well on Android phones.
 

chaby_91

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def not a vacuum leak. I'll try to get my hand on a scanner.

A/C makes it worse. rear defrost also makes it worse
 

chaby_91

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no. idle rises just a bit when any of these are turned on. Even turning on the headlamps makes the vibration worse.
 

f20bcg3

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no. idle rises just a bit when any of these are turned on. Even turning on the headlamps makes the vibration worse.
This sounds like what happen to me when i swap on the f20b..... turns out all my problem was, was a loose alt nut that was yet to be tightened. Would hurt to check that out
 

chaby_91

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all alt nuts are tightened and the belts are too. I've had this issue for a while now. It's gotten so bad it makes the hood vibrate. For a while I tought it was the rear motor mount, it wasn't.

Right now, I'm trying to figure out what happens with the engine between <1k rpm and >1k rpm. Something that opens or closes between idle and higher revs.

perhaps I'm looking completely in the wrong direction..?
 

chaby_91

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I called one of my mechanics friends... He said to try combustion chamber cleaner. And while I'm at it I'll also use seafoam. I'll leave feedback from this.
 

Tectonickz

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My entire interior and dash will shake viciously if my ac is on. But the second the car starts moving or I rev it up the shaking completely stops.

Chaby are you i4 5 speed too or?
 
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