2019 Mustang GT Auto Very Rough Idle/Engine Stall

[Bobby57]

Hello guys!

It started for me as well few weeks ago, exact same symptoms as previous posts, difficulties to have a stable idling and even few stalls. (2019 GT Auto)

I changed the oil (it was time) and the problem went away

Few months ago I remember the car almost stalling in a parking lot, but it was only once and I didn’t paid much more attention.

This might be a repeat of a previous post of mine, but I resolved my rough idle issue by having the throttle body and valves cleaned by my mechanic who dispensed a solvent directly into the throttle body.

More recently, I started experiencing hesitation when accelerating between 1K-3K RPM. This issue resolved after I tanked up with Chevron and did a good run on the expressway. It may have been that my injectors had gotten fouled?

BTW, I have a catch can, which goes a long way towards keeping things clean.

Though there are a number of issues that could bring about a rough idle, cleaning out the air/fuel delivery pathways is one possible solution that is readily and cheaply available, and it is not a bad idea, in any event.

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[njweatherman]

When I had my throttle body and mass air sensor cleaned, the problem went away for a bit, but then came back again. I'm still at the point of having the rough idle at a stop light when the car is hot every now and then, but so far, thankfully, it has not stalled or triggered a code. I off set mine by when I feel it coming on, I put the AC on and it raises the idle Band-aid solution for now.
BTW - how did your mechanic clean the engine valves?

 

[Gnatsum21]

I remember using Seafoam for that in my old Crown Viccy, and fogging up the hood at night.

 

[Bobby57]

When I had my throttle body and mass air sensor cleaned, the problem went away for a bit, but then came back again. I'm still at the point of having the rough idle at a stop light when the car is hot every now and then, but so far, thankfully, it has not stalled or triggered a code. I off set mine by when I feel it coming on, I put the AC on and it raises the idle Band-aid solution for now.
BTW - how did your mechanic clean the engine valves?

I need to ask my mechanic what it was that he fed into the throttle body that he said would flow through to also clean the valves. I am seeing him tomorrow and have made a note to remember to ask.

BTW, after I had gotten the things cleaned out so that my idle settled down, I put a catch can and crankcase breather on the engine and I have since not had a recurrence. I am constantly amazed at the amount of oil I empty out of the catch can that would have wound up in the throttle body, potentially to flow through to the manifold, valves and into the combustion chamber where it could foul the plugs and effectively reduce octane.

I also changed my PCV valve, out off an abundance of caution to ensure it is at 100% effectiveness to prevent crankcase pressure build-up that could potentially rob engine power (back pressure on pistons) and exert outward pressure on gaskets.

Having both a PCV system and breather is like wearing belts and braces :-)

 

[tuxity]

I also have an oil catch can passenger side. I clean it at every oil change and these is a bit of oil at the bottom. I have to add one driver side and check if it fits with my JLT intake (I was thing of this one not sure if it's good).

I also had to replace my PCV valve few months ago as it was making some noise.

I will follow your recommandation @Bobby57 and clean throttle body as well to make sure, thanks!

 

[tuxity]

Hello!

Well I still have the issue. It was ok the last months with last oil change but it’s coming back with oil life at 40% according to the car.

Just wondering, when you guys are replacing solenoids, which ones are you replacing? All of them?

I have ordered with my local Ford dealer the 2 intake VCT solenoids, maybe I should also replace the exhaust ones at the same time. (They are different right or I’m miss understanding something? )

 

[Sweetface]

yep $1700 later ( 2019 19k mileage car ) at a local performance shop to to find out it was a possible cam phaser / VVT issue. They cycled it a got it running and lasted maybe 5 weeks and came back. ordered a VVT solenoid ( exhaust ) for bank 2 . $40 and 45min later replacing it myself fixed the issue. Took a test drive to the shop which was 4 miles from my house and the shop basically said "well i guess we all learned something"

 

[KrayZJay]

I just want to say Thanks to all of you. This just happened to me yesterday. I bought a 2019 Mustang GT PP1 w/ magnaride with 15000 miles on it April 1st of this year and its currently at 19100 miles.

 

[Reapzz]

I'm currently also experiencing this issue with a 2019 Mustang GT 10r80. Going to get the shop to replace all of the VCT solenoids to be safe but was curious if there are any aftermarket ones that might possibly hold up better than the OEM ones? I want to avoid this issue happening again. I only saw the Ford performance ones but they only fit up to 2017.

 

[Cobra Jet]

I’m wondering if the VCT’s are prematurely failing due to engine debris getting jammed up in them. Meaning, when the engine is brand new and during assembly, any excess minute particles from casting, sealant used during assembly OR minute metal bits from engine break in mileage made its way into the VCTs during normal operation.

I’m really thinking if that is a possibility, because there’s just far too many Coyote users experiencing the VCT issues. Even Ford released a TSB I posted on here a while back that tells the Techs to do a cycling procedure to move debris out of the VCT. Sometimes that cycling procedure works, other times it’s VCT replacement time.

Thoughts?

 

[Dana Pants]

It’s really easy to create a solenoid cycling tool with a 12V power tool battery and multimeter leads. I tickled the heck out of a solenoid that threw a code and haven’t had it come back since. Cycling with the engine idling is pretty cool. Huge effect on how the car runs.

 

[Reapzz]

I’m wondering if the VCT’s are prematurely failing due to engine debris getting jammed up in them. Meaning, when the engine is brand new and during assembly, any excess minute particles from casting, sealant used during assembly OR minute metal bits from engine break in mileage made its way into the VCTs during normal operation.

I’m really thinking if that is a possibility, because there’s just far too many Coyote users experiencing the VCT issues. Even Ford released a TSB I posted on here a while back that tells the Techs to do a cycling procedure to move debris out of the VCT. Sometimes that cycling procedure works, other times it’s VCT replacement time.

Thoughts?

I've mostly seen 2019s with this issue. Haven't seen any 2020 or newer models having the same issue which is strange. Cause apparently they use the same solenoids in the newer models. I'm just doing a full replacement just to play it safe and I'm hoping it doesn't occur again. I installed a catch can on both sides so hopefully that helps as well.

 

[hope5oh]

2018 Mustang GT PP1 here with 42k miles, was experiencing rattles, startup noises, rough idles and weak acceleration. Ford issued to replaced my VCT solenoids. Should have the car back this week. Literally just bought this car 2 months ago so whoever traded it in, i hate you

 

[Cobra Jet]

2018 Mustang GT PP1 here with 42k miles, was experiencing rattles, startup noises, rough idles and weak acceleration. Ford issued to replaced my VCT solenoids. Should have the car back this week. Literally just bought this car 2 months ago so whoever traded it in, i hate you

Yea VCT issues seem to be common on the S550…

Just curious, seeing your posted mileage, is the repair going to be covered under the 5yr/60k Ford Powertrain and not be an out of pocket expense to you? VCT system is part of the engine, falls under the 5/60 Powertrain.

 

[hope5oh]

Yea VCT issues seem to be common on the S550…

Just curious, seeing your posted mileage, is the repair going to be covered under the 5yr/60k Ford Powertrain and not be an out of pocket expense to you? VCT system is part of the engine, falls under the 5/60 Powertrain.

it is covered. i have until june for the factory warranty and knowing 2018 tend to have the most problems ive gone ahead and bought the extended warranty too. good thing i did, but its my 2nd attempt to getting this fixed, first try they said they couldnt replicate the noise. 2 more attempts if it doesnt get fixed im gonna try to lemon the car. i started noticing it after having weird startup rattles not just on cold starts even warm. car stalled once while i was in motion giving it 3/4 throttle and ever since then its been rattling and i noticed a very weak acceleration and struggles to reach high rpms

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