2016 Mustang GT idle dip and stall

[Evil550]

Car feels like idle is not as smooth as it should be and every now and then while at a stop idle drops below 500 and back up a few times, sometimes it will stall when doing this. Car does this sometimes 4 to 5 times in a short drive. Been to dealer multiple times for this issue and they cannot figure it out car shows no codes. Spark plugs have been changed with no luck. Throttle body has been replaced by dealer and pcm flashed and this seemed like it fixed the issue for 2 days then it started doing it again. Now they are brushing me off telling me if it shows no codes so they can’t do anything. Instead of attempting to figure it they keep on trying to get me to trade it in for a new one. I laughed and told them why would I buy a new one when mine still has a warranty and you can’t fix this one. Have any of you guys had this issue or have an idea of what is going on.

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[Cobra Jet]

Have they checked the IMRC’s... the IMRC’s have been known and found to cause idle and drivability issues:

They should also be checking for cracks in the intake, another known issue where some members have had to have these replaced under warranty.

If you’re not getting good Service at your existing Service Center, try another (if one is close enough); some folks have done this in their region and receive better results.

 

[Evil550]

No they have not checked any of those. I did ask about if there was a way to check for cracks in the intake and the service rep gave me a very annoyed look and said I had to bring back as it was getting close to the end of the day and they didn’t have time. I guess I’ll be doing the early drop off to make sure they can’t say they don’t have time. Thanks for the response.

 

[Cobra Jet]

No they have not checked any of those. I did ask about if there was a way to check for cracks in the intake and the service rep gave me a very annoyed look and said I had to bring back as it was getting close to the end of the day and they didn’t have time. I guess I’ll be doing the early drop off to make sure they can’t say they don’t have time. Thanks for the response.

No problem - here’s a couple of threads for ya worth reading:
https://www.mustang6g.com/forums/threads/cracked-intake-manifolds.85551/#post-1910142

https://www.mustang6g.com/forums/threads/cel-p0300-and-p0308.70926/

 

[Evil550]

So fast forward car still has the same issues except now the for the first time a cel appeared. Took the car to autozone and used their scanner code showed P0012 vct solenoid over retarded bank 1. Same day lumbar support collapsed in driver seat. Dropped car off this morning on my way to work. Got a call at 5:00 pm same day that they car going to open engine up and dig deeper apparently it’s becoming a known issue and there is another mustang they are working on with the same problem. Estimated down they told me is two weeks possibly more. Btw my car has also had the tick since somewhere around 10,000 miles car currently has 35,000.

 

[Cobra Jet]

So fast forward car still has the same issues except now the for the first time a cel appeared. Took the car to autozone and used their scanner code showed P0012 vct solenoid over retarded bank 1. Same day lumbar support collapsed in driver seat. Dropped car off this morning on my way to work. Got a call at 5:00 pm same day that they car going to open engine up and dig deeper apparently it’s becoming a known issue and there is another mustang they are working on with the same problem. Estimated down they told me is two weeks possibly more. Btw my car has also had the tick since somewhere around 10,000 miles car currently has 35,000.

Ahhh.... one of good old VCT issues...

Here ya go, the attached TSB may help, attached SSM or this other thread relating to VCT issues:
https://www.mustang6g.com/forums/th...-5-0-coyote-vct-solenoid.113879/#post-2475258

 

[Perfect1on]

Heyy brother what was the outcome after your dealer had your car mines doing the same exact thing yet it hasnt thrown any codes at all yet

 

[Evil550]

So they ended up replacing the right intake cam phaser and vct solenoid and all necessary gaskets and changed the oil. So the service receipt says. Car feels noticeably better and idles better for the past two weeks now. Car still does not idle as smooth as it should though.

 

[Perfect1on]

Ahh ok i see ya its crazy mines not throwing any codes but im thinking if its possibly the same thing my idle litterally sometimes will go up and down constantly and sometimes just stick at a high idle by itself then sometimes just randomly die out and occasionally the rpms would do that dip u described where it would go so low u feel like the cars about to die and then jump back up been trying to figure it out for awhile now cause it wont throw a code at all sadly so im hunting blind for the issue

 

[Evil550]

Yeah mine did that for almost a year until it finally threw a code. Sorry to hear your going through the same thing. Good luck to you and let us know what it is when you figure it out.

 

[Perfect1on]

I will forsure get back to you on what i find out dropping it off with my tuner and his tech to dig in and see whats going on this week ill mention to them what ford replaced on your car aswell to give them a idea on where to start

 

[Zinc03svt]

I had almost the same thing with my 18 gt w/ 5k miles. Ended up being an air leak from an AEM dry flow panel filter. Fyi.

 

[fahadco80]

Yeah mine did that for almost a year until it finally threw a code. Sorry to hear your going through the same thing. Good luck to you and let us know what it is when you figure it out.

Hi,

Mine is 2019 GT with 10R80, I am having the tick noise only while car warming up, engine rattle at 2.5k when deceleration, both appeared exactly after my second oil change (20,000 km service), now I am having the RPM fluctuation and engine stalling issue when coming to a stop or when I come to slow down for a road bump, I get a yellow warning on my dash saying (put transmission in natural and re-start the car), when I restart the car, car drives back normally as if nothing happened, sometime it happens twice a day and sometime I don't have any issues for months, never through a code, dealer couldn't find any thing.

You mentioned that even after changing the cam phasers, the RPM issue came back, but may I ask you if you had the stalling issue too?

Thanks

Fahad

 

[Evil550]

Yes car stalled while rolling up to stops. It was very frustrating. I ended up getting a lemon law lawyer and ford took the car back and paid me out.

 

[alpha_s550]

I had a 2018 GT Premium with the 10R80. I babied the car but started noticing issues. I also had my trans stall while rolling up to stops and also had the notice to put car in park and restart. I took the car to 6 different dealers, ofcourse.. no codes and no answers. My car also had the rattle upon deceleration and RPM's also fluctuated. My car also had the tick but 24/7, just louder during cold start.

I hired a lemon law attorney 8 months ago and just yesterday, after going through literall hell, I dropped off the car to Ford and will be getting my buyback check next week.

Just letting everyone know because these ARE major issues and no one should be paying for a car with these issues.

I'm going to be getting a 2020 of the same car but am praying that I don't experience the same issues. I just love the car to much and can't see my self in another car. Even working at a BMW dealer and having access to any car at a discount, I still chose the Mustang along with Ford's insanely discusting servicing departments with the car.

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