I have a 2021 Mach 1 with 1,700 miles, no modifications. The vehicle has now populated random misfires on three separate occasions. I've only put premium Chevron in it, and this has happened over multiple tanks. The local Ford dealership was unable to duplicate it (it has happened with both cold and warmed-up engines, always at part-throttle), and there are no TSB's. Since the basic engine is the same as a Bullitt, does anyone know of similar issues on that car? Thanks in advance.

 

Unfortunately, I don't own an S550 model, so I'm unable to provide an explanation for the misfire issues. Perhaps taking your Mach 1 to another Ford dealership that's more familiar with the Bullitt/Mach 1 engine can troubleshoot the misfire issues your going through much better? Meanwhile, hope you get everything resolved as soon as possible. Also thanks for sharing an image of your new 2021 Mach 1.. She's a real head turner..

Congrats and welcome aboard

 

I am having this exact issue right now! Did they find out what was causing your misfire? Thanks

 

Welcome to the forums MoreHP, ya lurker. Took ya a minute to post, eh? And also to Beth, welcome to you too!

Ok, so... And bear with me, it's been a minute, but I'll ask my guy at my work about it and relay what he recalls about it...

There was a new car on the market, the Scion FR-S (now the Toyota 86, nee Subaru BRZ, a 'joint venture' much like the current Supra is about as much a Supra as it's actually a BMW Z4, but I digress), and back then people were quite excited to get them.

Except some people, for no reason discernable, were breaking their engines. A lot of people. Not everyone, but enough it became a concern. One guy had his FR-S car stuck in the shop for *months* while it was sorted out between him, Toyota (who owned Scion, now defunct) and... Chevron.

Yes, Chevron. Specifically, the Subaru engine was killing itself due to the Chevron additives. I want to say it was popping off valve keepers, but can't be sure. See above recollection disclaimer-for-the-time-being, but not about the Chevron gas part. That was determined to be THE link of all these particular failures. I don't have the answer why or what the fix was (I assume redesigned springs/keepers/?)

Source: Me, works at a Toyota dealer group, always in all kinds of areas fixin' stuff as my job and curiosity makes me wander near the bays and get info.

---

Secondly, much less related, but figured I'd say: My ol' 1966 Thunderbird would run on Texaco gas (back then) and Diamond Shamrock (again, back then), Exxon, and that was *it*. It might run ok on other gas, but the one gas you NEVER stuck in that thing was Shell. I mean, I don't know why, but back then, she would do weird things like stall on a left turn, or not go when I said go... made noise... I didn't much care the why of it, I just got really good at avoiding all Shell stations. Wasn't hard, had a DS by the school, had a Texaco around the corner, them Exxons were near the work... not a problem to avoid the Shell. Only on a trip did it become an issue, and I didn't really road trip the TBird that much.

Anyway. All that to say maybe try changing your gas. I know Chevron's supposed to be it for a lot of people, but sometimes cars don't like certain additives or gas. Dunno if it works or helps, but it can't hurt either...

/By the way I love Love LOVE those wheels on that thing! SO good.

 

Thanks for the info, I also use Chevron gas! Hopefully it’s an easy fix!

 

I sure dislike hearing owners having issues with new American muscle cars. Not a good thing. The type of gas should have no bearing at all and should have been caught by someone at Ford before production. Now it's an owners problem
To both owners that have posted, please get back with us and let us know what happened.

 

Well, to be fair, it's not exclusively the gasoline. Gasoline is a relatively simple long chain of hydrocarbons. The difference is in the amounts of carbon chains in the molecules... think it's 15-18 or something like that. More 18s mean higher octane as it's harder to get that to combust than the lesser chain 15s. But there's more 15s than 18s when you refine the raw oil, it's easier to get that. So that's why the premium vs the regular and why running regular results in knocking in a higher compression car that is made to run best at the higher octane, and also the price difference.

But that's a refined, just gasoline issue. Any car should run on any 87 or 91 (or higher, read more refined and expensive) gasoline only, without addtives. Without additives, there would be zero difference to speak of and none of these brand or even regional specific issues would occur.

The different brands like Chevron or Shell or whomever will add things like Chevron's famous Techron to the gasoline to help clean injectors and/or valves, or prevent soot, whatever their want/need is. And those additives are what causes the problems like the aboves that I mention.

Then you add the ethanol into the mix too. Whee. 'Up to 10%' means anywhere from 0 to 10. You just don't know what you're gonna get. Then the ethanol can add water to the tank because it likes doing that: helping the fuel absorb water. Which then gums up things... A little water isn't bad, a lot is. And sitting around makes it worse. Which reminds me... I gotta go start them vehicles...

And you want *FORD* to figure out all that ahead of time? In every town, every brand, every pump? And I've not even mentioned the conditions of the station's tanks, their pumps... heck that Addtech stuff they have around here, maybe it's leaking into my gas and screwing things up for all I know...

Ford's not the problem. Standards and practices are. No two gas stations, even the same brand, are alike.

All that is if it's the problem for any particular person/car. Most won't have the issues at all, or don't notice, or worse don't care. For me and Awesome, so far so good, although I try to use good stations, and I know my particular area's stations pretty well and trust them. So far so good.

And one other thing. I don't know which brand they may tote today, if they do at all, but before I had to replace my original gas cap on Awesome, what did Ford have printed on it? "We recommend BP Premium fuels". I don't know about anyone else, but that's Ford telling you what to buy. Y'all buyin' Chevron and Shell? That's not allowed, obviously.

/I ain't got no BP's round here either, so worry not, I'm breakin' the law too.
//Related video:

 

Shell V power, Exxon Supreme, and sometimes Race trac never had any issues.

 

Took my 2021 Gt in for a miss. I bought it with with 3 miles on it. A week after I bought it I drove it from NC to
OK for Christmas. A lil over a 3000 mile round trip. So I put some serious miles and time in quick. I’m 46 yrs
old and have owned several mustangs in my life. Am also a diesel mechanic so I know a lil bit about engines.
I took it back to the dealership, told me could not replicate condition and handed her back to me. Told me it was just the way the10 speed shifted, suggested I don’t “lug” it. Lmao…. I’ve never lugged anything brother. Every mustang I’ve ever had was a complete “fireball”! This 2021 and it’s “miss” has left a bad taste in my mouth….

 

Welcome to the forums!

Since this thread's revived now.. I've seen FordTechMakuLoco show off the monitoring of the Ford computer with the software, and the fact that the engine shows misfires and keeps count.

Wouldn't that show up? Or did I miss something about tracking the misfires? I mean, if it was a consistent misfire on, oh, cylinder 8, you'd attack that and get it figured.

I'm thinking either coil pack, plug or water/oil in the plug hole, or the coil pack boot is compromised...

...wait, also, aren't these new Coyotes direct injection as well as port injected for lots of reasons? Perhaps the injection isn't doing the job, and an inspection is in order...

Just thinkin'. With all the new tech and processes and programming and procedures and and and... I'm constantly reminded of Scotty in Star Trek III:

 

Geez, I imagine it would. I'm so sorry to hear that as I want a new Mustang eventually too. Maybe another dealership???

 

After the experience you went through, I would never do business with that dealership again. I'd recommend searching for other dealerships until coming across the right one worthy of earning your business as a valued customer.. Meanwhile, welcome aboard.