Idling a little rough....?

[oceansidesam]

I have an 04 cobra w/25K miles which Idles a little rough. The revometer is completely steady but every 5-10 seconds theres a very light tremble to the car. what can it be? spark plugs, fuel filter?

 

[68_GT]

I have an 04 cobra w/25K miles which Idles a little rough. The revometer is completely steady but every 5-10 seconds theres a very light tremble to the car. what can it be? spark plugs, fuel filter?

pull all your coil packs and look at them to be sure there's no moisture down in them. Rather than check all your plugs I'd just replace them. They're not expensive and if you go through the trouble to pull them you may as well just put in new ones. Betting it's something like that. Could be a loose connection to a coil pack or a fuel injector. Highly doubt it's the fuel filter.

I'd list your mods too so we know what if anything has been messed with.

 

[Jomo1994z71]

I have the same tremble...very very slight though...subscribing...

 

[bigmoose]

i had the same problem. i fixed it by removing the engine and putting in a 1.8L 4 banger. couldn't feel the tremble anymoreoke:

 

[spitin venom]

All my cars have done it. I think it is normal.

 

[Jomo1994z71]

I agree...it's a musclecar:shrug:

 

[gt347mustang]

does the idle rpm change?

 

[chitowncobra]

All my cars have done it. I think it is normal.

+111 same thing its normal!! but for me its a very sublte constant vibe,like its cammed!!! :burnout::burnout:

 

[Juruense]

My car has always done that and I have tried the following to correct it:

-copper plugs
-OEM plugs
-reset PCM numerous times
-clean MAF
-clean IAC
-replace IAC
-had dealer reflash PCM with latest calibration
-seafoam
-new fuel filter
-removed tb and plenum and cleaned them

To be honest I am out of ideas short of a custom tune and asking tuner to be sure and eliminate it. It only does it when the car is warmed up also. So ANNOYING!

 

[SB VENOM]

Im pretty sure this is normal.....I have it too :shrug:

 

[oceansidesam]

Thanks Fella's.... thats all I wanted to hear. I'll probably change the spark plugs since I just bought it and dont know when they were last changed. Hey Big Moose.....you had me cracking up with the swap joke.

 

[Farmer-Ted]

If you get a tune, have them turn the idle speed up to 750-800 rpm. Much smoother.

 

[ShelbyGuy]

Run a compression test. A dead cylinder will cause a miss.