I have recently got a 5.0 2011 mustang GT. I have ~1800 miles on it. I had a question for any one else that has also recently bought a 2011 mustang gt.

At a Idle, the RPMS are not constant. They range any where from 550-800. It will never stay at one area. And you do notice the movement in the rpm needle.

Anyone else notice this? Or is it just my car.

Plus, my car usually takes about 3-5 cranks to start. There has been 2 times so far that the car just sat there and kept cranking untill about the 15th crank it fired up.

I've had the dealership look at it. They told me they don't see anything wrong with the car. They have checked with the ford engineers to see if there is an issue. They will be looking out for any one else with these issues if a fix does arrive.

To me, this doesn't feel normal and I am trying to get on top of it before some thing does happen to the car.

 

My 11 year old car with 32K mi on it....or my once owned 95 mark 8 with 162k mi NEVER took more than once to crank and start....

I would not let this slide since its under warranty.... I would keep taking it back to them and make them figure it out....Or bug them enough to where they keep it and give you a rental and not take it back until they fix it.

 

I took a short video of the Idle. It wasn't doing it as bad as it does some times. But that is pretty much what it usually does. I don't recall it doing that when I first bought it.

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http://www.youtube.com/watch?v=9zE85D3N-FE

I guess the embed didn't work. There is a link to the video.

 

Nothing in that video seems out of the ordinary....just becuse it bumps by a couple rpm doesn't mean there is something wrong. Maybe you just didn't notice it when you first bought it? If it would idle at 800 then go down to 400 and back up to 800 then it's usually a bad IAC valve but what you have seems normal.

The no start after a couple of cranks is what would get me. That's not normal lol

 

Yeah, I wasn't too worried about the rpm movement. What the dealer told me made perfect sense. But I just wanted to make sure it was normal with other people.

About the cranks. I just want to make sure we are on the same page. When I say 3-4 cranks. I mean the engine will turn over about 3-4 times before it fires up. There has been 2 times so far where the engine turned about ~15 times before it fired up. That is not normal. Also what the dealership said.

And it is possible I didn't notice the rpms when I first bought it. The dealer gave me a couple reasons that this is happening.
1.) To work with emissions, the engine is leaning out at an idle. (But if I give it gas and hold it at a rpm in neutral. The rpm fluxes a little as well. As seen in that video)
2). With the high performance engine with almost a 11:1 compression. The o2 sensors are constantly leaning/richening the engine to make the cat converter work correctly.

I am more worried about the starting issue though. Other than that, the car runs and sounds great!

Ignore my bad driving =P Been a while since I drove stick, plus I wasn't trying to do fast shifts because I'm still breaking in the car.
Heres the car
http://www.youtube.com/watch?v=3i3i9HXqY60

 

idle looks fine to me too...that was not 550 to 800 as you described unless i zoned out and missed something. looks like your rpm are fluctuating maybe 100 rpm which is normal as far as im concerned. my car and my bike bounce far more than that. my car with the ac running at a stop light will occasionally dip to 400-500 when the ac kicks up but that is far more drastic than your video.

as for 3-5 cranks i don't know you'd have to post another video. i cant help but feel your just looking to find things wrong with your car after that idle video. a couple turnovers before the motor fires isnt necessarily out of the ordinary either. do you let the fuel pump prime before you start cranking it? meaning put the key in run position, you will hear a whirring noise from the back of your car (thats the fuel pump priming), then start it once the whirring stops (couple seconds). my car can be a little picky from time to time if i just stick the key in and immiedately start cranking it without priming the pump.

 

^^ I agree with letting the fuel pump prime. Mine will take a little longer to turn over if I don't. But 15 cranks or so? That seems a little long still.

 

Maybe it is just an issue with the computer. The pointer of RPM gauge in my 2010 also does strange things after turning the engine off. It goes to level 0, then after a while a little bit lower, then back to normal level 0. I may put a video up about it... It feels like a living entity under electrocardiogram being sad about game is over.
However, I haven't experienced that kind of fluctuation your car has.

 

Like I mentioned before, the big movement didn't happen in that video. I'lt does happen when the a is on or off. Ill make anoher video of the crank tonight.
The rpm usualy does that small movement. But there are
times where it does it more than others.