2019 Mustang GT Auto Very Rough Idle/Engine Stall

[Jaay_d5.0]

After a month and 3 days i finally got my car back and this what they wrote on the paper

Sponsored

 

[IrishStallion]

I had intake cam phasers replaced 1.5 years ago and I still occasionally get that rough idle. I had my tuner bump up my idle rpm to 750 rpms and it has not stalled since doing that. Fyi...

 

[Elp_jc]

I wasn't expecting 2019s having that issue still. May I ask what's the build date (on upper left corner of white label on driver's door pillar) on your car? At what mileage did it start happening? And how often have you changed the oil, and with which one? Just trying to find a pattern. Thx.

 

[Jaay_d5.0]

I wasn't expecting 2019s having that issue still. May I ask what's the build date (on upper left corner of white label on driver's door pillar) on your car? At what mileage did it start happening? And how often have you changed the oil, and with which one? Just trying to find a pattern. Thx.

7/18 is the built day and i believe the mileage was around 16 k bought the car when it had 15,700 so I don’t know when the problem first occured i am the second owner and i always change my oil every 3-5 k miles it does have a roush tune.

 

[Jaay_d5.0]

I had intake cam phasers replaced 1.5 years ago and I still occasionally get that rough idle. I had my tuner bump up my idle rpm to 750 rpms and it has not stalled since doing that. Fyi...

I do have a roush tune so far no rough idles but i have seen my rpms rev very little on red lights is that normal?

 

[Cobra Jet]

After a month and 3 days i finally got my car back and this what they wrote on the paper

Another VCT repair (as suggested in post 52)... I’m wondering if the VCTs used are just supplier garbage because there’s been quite a few VCT posts on this site with many being repaired under warranty.

 

[Jaay_d5.0]

Another VCT repair (as suggested in post 52)... I’m wondering if the VCTs used are just supplier garbage because there’s been quite a few VCT posts on this site with many being repaired under warranty.

Are we suppose to give them some time to break in ?

 

[Cobra Jet]

Are we suppose to give them some time to break in ?

No, never have seen documented or heard of any needed VCT break in period for a new S550 Coyote as built from the factory, or one that has had the VCT’s replaced.

 

[Elp_jc]

It'd be nice to know what they're failing. On the Ford site, it was said the lack of lubrication when cold eventually ruined them. It obviously shouldn't happen, but many of us started using 0/30 oil to hopefully avoid that fate... but it was probably just going to extend their demise, if truly defective. But not all fail, so it has to be either a tolerance issue (if random), or a bad batch, or batches. At least on the Mustangs, it's not a wide-spread issue yet, right? But what I don' t like is I've seen several 2019s affected too, but no build date. Hope my late 2019 has 'improved' VCTs, since Ford must have changed something after so many failures in 2018.

By the way, the bad ones are the Borg Warner ones, which I believe are the exhaust on the Coyotes. On the 3.5EB, ALL cam phasers are Borg Warner, so more likely to fail. That was the main reason I traded it for the Bullitt. Hope I didn't make yet another mistake. Ha ha.

 

[SHxTGUN]

It'd be nice to know what they're failing. On the Ford site, it was said the lack of lubrication when cold eventually ruined them. It obviously shouldn't happen, but many of us started using 0/30 oil to hopefully avoid that fate... but it was probably just going to extend their demise, if truly defective. But not all fail, so it has to be either a tolerance issue (if random), or a bad batch, or batches. At least on the Mustangs, it's not a wide-spread issue yet, right? But what I don' t like is I've seen several 2019s affected too, but no build date. Hope my late 2019 has 'improved' VCTs, since Ford must have changed something after so many failures in 2018.

By the way, the bad ones are the Borg Warner ones, which I believe are the exhaust on the Coyotes. On the 3.5EB, ALL cam phasers are Borg Warner, so more likely to fail. That was the main reason I traded it for the Bullitt. Hope I didn't make yet another mistake. Ha ha.

Mine was built 1/2019 if that helps. So one of the earlier 2019s.

 

[IrishStallion]

5/2018 build date here

 

[SHxTGUN]

Noticed something interesting today. So I’m tuned now and have been for a few months. That tune raises the idle RPM up to around 760-780ish for me. I haven’t been on the stock tune since I first got tuned months ago.
Today just for fun, I decided to flash back the stock tune just to compare how it rode back then. Well, the stock tunes idle is about 650ish I believe. Within a few minutes after starting the car and stopping at a light, I began to feel rough idle coming on. First time I’ve felt it in a while.

Anyways, I know someone mentioned it earlier in this thread, but raising the idle RPM via a tune is a HUGE help with this issue too apparently. While tuned I think I felt rough idle once or twice (and it did stall out on me, but that may have just been an anomaly?). So once or twice within the months I’ve had it on. And then I back to stock tune with 650 idle RPM and feel rough idle almost immediately. Needless to say, I’m sitting in a parking lot flashing back my tune right now.

Just thought I would mention this. Obviously tuning comes with warranty issues and big costs so I’m not saying this is a surefire thing, but just noting my experience after this stock tune experiment.

 

[IrishStallion]

^^^^ That was me. ;).

Mine has never stalled since moving to 750 idle via tune.

 

[Jaay_d5.0]

Do the 2020 gt 10r80 have the same issue? My car stalling/rough idling/ rpm flactuating again after intake cam phasers replaces and re tune done ! Anyone solve the issue yet?

 

[IrishStallion]

Do the 2020 gt 10r80 have the same issue? My car stalling/rough idling/ rpm flactuating again after intake cam phasers replaces and re tune done ! Anyone solve the issue yet?

Yeah unfortunately no. I would also say these cars are very sensitive to battery voltages. Have you checked your battery?

Sponsored