Engine problem with my 07 mustang
 

My mustang just turned over to 30,000 miles. Yesterday it started to act strangly. Seems to be missing out some, then got a whole lot worse as I went down the road. The RPM would go up and down, then up and down.
What could it be???
Thanks
S Peterson

Well posting this in the 4.6L V8 section would get more answers. What mods do you have if any? What part of KS are you from? Some more info with the car would help.

I had perhaps the same or very similar problem with my 2006 a couple of years ago. Turned out to be the throttle body - replaced under warranty, problem solved.

More info
 

This is my 1st ever post on here. Sorry if it was in the wrong area!
My mustang is a automatic 6 cyl.
It has been running perfect until Thurs.......we had frigid cold temps and trememdous wind. Didnt think that really had anything to do with the engine.
My "wrench" light even came on. I was only driving it for about 10 minutes when it first started. Then it got alot worse fast.
Could it possibly be bad gas, as I has just filled it up the day before.?

I saw it was your first post...just trying to lead you in the right direction for some help.

I was asking were in KS because here in wichita its been pretty cold out lately and we have had some gas stations in wichita that have had a lot of water in the gas. My sister in law had this problem with her cobalt 2 days ago. Had to drain the tank and change fuel filter.

wow what stations were doing that?

Yea you have to be careful where you go here. Its mostly no name stations though. There has been a handful of gas stations that have been turned in for leaking tanks(causing water to get in). The name my sister went to seriously didn't have a name on the building or a sign. Thats why I always use QT.

Yep, here in Belle Plaine.
I havent driven it since Wed.
I'll drive it again today when it warms up to see if its still bad.

Your description of the problem is somewhat vague and what you mentioned could be caused by quite a number of things. If you could let us know if it starts normally, how it idles, what happens under heavy load and any other symptons, that should help. Do you have any mods? What type of weather had the car encountered prior to the problem that might be unusual? Major temperature swings? Ice?

Did it begin to act up within 20 miles or so of a fill-up?

If you can let it sit overnite in a garage, see if it repeats the problem. The fact that it happened suddenly could be weather or fuel related.

YEP, my guess is water in the gas.
I filled it up on Wed evening. Put it in the garage overnight. Drove it out of town on Thurs.......during the horrific cold north winds.Started missing out about 2 miles from home.
Drives perfectly today.......drove it up to 90 mph with out any hesistation.!
You can bet they will get a piece of my mind tomorrow......at the Belle Plaine gas station.
Pass the word around.