unsteady idle and vibrations.

[black2008gt]

Have a 12 gt with an idke that loweres and raises most of the time onky slightly (100 to 200 rpms) also get a slight shudder whie idling. Tranny is noisy but shifts fine. Is this normal for the 5.0s or should I take it to ford. Never had this with my 03 cobra.

 

[slvr08gt]

Have a 12 gt with an idke that loweres and raises most of the time onky slightly (100 to 200 rpms) also get a slight shudder whie idling. Tranny is noisy but shifts fine. Is this normal for the 5.0s or should I take it to ford. Never had this with my 03 cobra.

Mines doing the same thing right now. Are you on the stock tune?

 

[Wicked GT]

Mine does the same thing. The shuddering I feel is when my fan kicks on. Not sure if that is your issue as well but next time you feel it see if your radiator fan is on.

 

[fun4me]

Mine did that w/ Diablo tunes on my '12. No matter how many revisions. But idle/runs just fine on the stock tune.

 

[ddd4114]

Mine has done that occasionally ever since I bought it, even on the OEM tune. From what I've read, it's pretty typical for the new 5.0's.

 

[BAKnBLK2010]

Rough idle here also on stock tune. Mine even sounds like it has a dead miss at idle sometimes. My 2011 did the same thing on the stock tune and aftermarket tunes.

 

[black2008gt]

Yea im on stock tune. Is everyones trasmission kinda loud, i hear a faint whine in it nothing to get to crazy over and with the windows down i hear alot of little noises along with the throwout bearing engaging.

 

[UltraKla$$ic]

Have a 12 gt with an idke that loweres and raises most of the time onky slightly (100 to 200 rpms) also get a slight shudder whie idling. .

This was painful to read.......

LOL!!

 

[black2008gt]

Sorry about that i was typing this at work with my boss jawing in my ear. Wont happen again. Damn public school education let me down again.

 

[UltraKla$$ic]

Just messin witcha.

 

[WytHorse]

Rough idle here also on stock tune. Mine even sounds like it has a dead miss at idle sometimes. My 2011 did the same thing on the stock tune and aftermarket tunes.

exact same here, sometimes even sounds like a little miss..noticed it more so when I took off the mufflers bc I could hear it better. The 12 I used to own did the same, just another quirk I suppose. Stock tune on both.

 

[3vstang]

Rough idle here also on stock tune. Mine even sounds like it has a dead miss at idle sometimes. My 2011 did the same thing on the stock tune and aftermarket tunes.

Same here. Stock tune, 15k miles, sounds like a miss at idle. I have checked everything. No vacuum leaks, plugs are good, cleaned the MAF & TB, checked all my exhaust connections for a possible leak (thinking maybe I was hearing things) and I don't have any codes. Hell, I even took the intake manifold off, checked for any cracks/areas for a possible leak, cleaned it and then re-installed everything with the proper torque specs, no difference.

I've been searching around and quite a few people seem to be experiencing the same issue. I was going to install my wideband next to monitor my AFRs, but I thought it'd be ridiculous for the stock tune to be off. The only thing I haven't checked/replaced is my O2 sensors, but if they were faulty they should throw a code.

I'm at a loss now since this is a stock motor car, and it runs great. I guess until I experience a problem I'm gona say fuck it.

 

[Sky Render]

When idling at stoplights, I feel an occasional "bump," almost like someone behind me at the light gently nudged my rear bumper with their car. Is that what you're referring to? My car is on the stock tune and has done it for the last 30,000 miles. I'm not worried about it.

Sorry about that i was typing this at work with my boss jawing in my ear. Wont happen again. Damn public school education let me down again.

 

[black2008gt]

Yea thats what im reffering to, also get a rattle or tick around 1000 to 2000 rpms. My build date is 12/11.

 

[G.T]

i had a 2011 GT in my shop that always had a bit of a rough idle with what felt like random misfires and we never got it tuned out, till the PCM developed a fault and had to be changed.. after which i carried out a procedure recommended in the service manual using the IDS VCM (Dealer diagnostic tool) called "Relearn neutral misfire profile" and the idle misfires almost completely went away.

the procedure is required when a new PCM is installed.. but i did it on a 2012 GT that came in for a service and had the exact same result.

might be worth looking into

 

[slvr08gt]

i had a 2011 GT in my shop that always had a bit of a rough idle with what felt like random misfires and we never got it tuned out, till the PCM developed a fault and had to be changed.. after which i carried out a procedure recommended in the service manual using the IDS VCM (Dealer diagnostic tool) called "Relearn neutral misfire profile" and the idle misfires almost completely went away.

the procedure is required when a new PCM is installed.. but i did it on a 2012 GT that came in for a service and had the exact same result.

might be worth looking into

Interesting

 

[WytHorse]

...along with the throwout bearing engaging.

Oh yes, that one too. Surprisingly loud actually. Again, both the 12 I owned and my 13 did this ? nature of the beast I guess.

 

[black2008gt]

I guess it is. Cant really bitch too much i guess out performs my 3v like night and day. Guess thats what happens when you get m3 perfomance at a third of the price.

 

[HEMI LOL]

checking in with the same thing. my car has done it since day one(20miles on the ODO). ive asked around, and every 5.0 guy ive talked too has it.

seems to be the nature of the beast. whats interesting is on my BAMA 91 race tune it does it the least compared to stock tune and the performance and street tunes. car seems to run fine, and at 7k miles its seems to be a non issue.

 

[Sky Render]

I think it might be an emissions thing, varying the idle A/F ratio to keep the catalytic converters operating at a specific temperature.