GT - Rough start when warm

[Johnjdpower]

I just picked up my new GT Prem from the dealer on Saturday, about 20 miles on the odometer, I felt like I was one of the only people to ever drive/test drive the car.

Anyways, to stay on track. I have noticed (sometimes intermittent) that when I start the car when it is WARM or WARM OUTSIDE (100degrees+) that it seems to have a hard time turning over.

I was wondering if it is possible that the dealer put 87 octane in the car, and it is still on the first tank and this is the cause (air/fuel mixture)? As to try and keep the issue reproducible, I have not added any 93 octane to the tank, but could this potentially resolve the issue? Why would Ford allow 87 in the car if it potentially causes this issue?

I have set up an appointment later on today to have them take a look, hopefully I will be able to reproduce the issue in front of them. If not, any thoughts on the possible cause?

Any insight would be appreciated or if there is any additional information that is required for your advice.

Sponsored

 

[kz]

87 will not cause any issues - so that's not it.

 

[Chameleon]

You can run 87 or 93. Run another tank of gas (93) and see if it continues or goes away.

 

[RIBS]

Mine was hard to start and idled rough when brand new. After a few months the issue is gone....

 

[Johnjdpower]

Mine was hard to start and idled rough when brand new. After a few months the issue is gone....

I was able to replicate the issue.

1. Ensure the engine is warm (drive around town).
2. Park in the hot sun (100+ degrees)
3. Wait for approximately 10-15 minutes in the heat
4. When attempting to start it will start very hard.


I took to the dealership this morning and told them the replication steps and am waiting for a response on their findings. I will update with what they say.

 

[Johnjdpower]

The dealer called me back and stated they "could not replicate the issue" regarding the hard start but were able to replicate the Remote Start not working. Therefore they replaced the key and said it should be fine.

Unfortunately it is not in triple digit heat today so they couldn't replicate the steps. Therefore I picked it up and will try again when the weather gets hotter (hopefully later this week).

 

[JKstang]

John, this is really strange because I have exactly the same two issues with my GT. Starts great cold but drive it for 10-15 minutes and shut it off and restart and it sounds like its not going to kick over sometimes. The strange thing is that my remote start doesn't work either on both keys, weird that we have both similar symptoms. I'm curious if yours starts any better once they fix the remote start issue (though I can't see how it would be related but who knows). I haven't had a chance to take mine in to the dealer yet, hard to believe I haven't even passed 500 miles yet and this thing takes longer to restart than my new lawn mower.

 

[IvanCRF]

Sounds similar to this:

http://www.mustang6g.com/forums/showthread.php?t=18508

 

[madweazl]

You initially mentioned that it was tough to turn over. With that said, is the problem the battery turning the engine over or is it running rough after starting?

If it is hard to turn over, have a load test performed on the battery. If the battery is good, start tracing power to the starter looking for corrosion or lose connections. Make sure the ground is secure.

 

[np0531]

Any updates on this?

I have the same problem...it takes a few too many seconds to turn over sometimes. Usually happens after i've driven it and then parked it for a while outside and the engine is still warm. I'm in Miami, so the temperature is always over 90 degrees ambient. When I turn the car on the inlet temp is usually at 130+.

I've been using 93 since day one, and i've had the car about 1.5 months with about 4000 miles on it. It didn't really have this problem when I first got the car, only lately it seems.

 

[Johnjdpower]

Any updates on this?

I have the same problem...it takes a few too many seconds to turn over sometimes. Usually happens after i've driven it and then parked it for a while outside and the engine is still warm. I'm in Miami, so the temperature is always over 90 degrees ambient. When I turn the car on the inlet temp is usually at 130+.

I've been using 93 since day one, and i've had the car about 1.5 months with about 4000 miles on it. It didn't really have this problem when I first got the car, only lately it seems.

Sorry for not providing an update. Once I started using 93 then it started to not have any problems starting. In Dallas it is still around 100+ and it stopped having rough starts when I switched to 93. Took about a tank or two though. Sorry that doesn't help you since you have been running 93 for some time, it did fix it for me. Hopefully you don't have a bigger issue :(

Sponsored