Is this engine just kinda rough?

[lakesinai]

First.. background on me…. I’ve built a few v-8 engines for street and drag… tuned tubo rotaries in RX-7s and two carbureted 360 swaps into jeeps…. So.. this isn’t my first rodeo!!!!!

ANYWAY…

Just got our Bronco last week, black diamond 4 door with steelies and the 32”all terrain tires, I wanted the 2.7 all the way the 4 just seemed like it was wound too tight!!!

BUT……After a week and 400 miles, I’ve noticed that the engine isn’t as smooth as I thought it would be.

It’s not acting up (at least I don’t think so… but that The point of this thread.)

It idles kinda rough… especially at cold start….. I put high test in it and that helped a but..

It’s noisy, lots of belt noise and i swear it sounds like my Harley where you can hear the valve train, and there’s definitely injector pulse making itself known.. way louder in front of the car than our pacifica with the 6 cyl pentastar..

It’s lumpy…. At take off, if your not on the throttle hard, it kinda seems like you can feel each piston firing until you get up to 2k… From my turbo experience though, its not surprising, lower compression with no boost at low throttle and new turbos that are still tight tend to feel a bit lumpy….

I also know its tuned for torque and im not used to mud tires anymore….

My wife….. who knows nothing about engines except how to put her foot down…. Does hear or feel a thing!!!!!!! But me… i’m like…. Eeehhhhhhhhh i dunno!!!!!!

But……..I just wanted to know if this is all normal, or there’s anything i should be lookin out for!

40,000 miles and nearly 2 years on my 2.7 in an OBX. Yes, it is a bit "rough" at lower RPM when not under load on 87 octane gas. Hit the road, and the gas, let the turbos kick in, and that sputtering is forgotten. I have found that, as you wrote, that 91 or 93 octane makes it smoother running, and also increases mpg by 1-2 mpg. Very nice, reliable engine. Had the 2016 version of the 2.7 in my previous F150, and it was similarly reliable and flawless. I change the oil every 5,000 miles.

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[TCB-1]

Yeah, same here, my 2.7 (2023 OBX) has about 3500 miles on it and it has noisy start up and lumpy idle - particularly at cold start up. Quiets down once warm, but still sometimes feel the lumpy idle. Don‘t recall my 2018 Raptor 3.5 being this noisy (in general) until the cam phasers went bad at 40k miles. Most frustrating to me is the hesitation when warmed up and lightly accelerating from a dead stop, just feels like it’s lost between 1st and 2nd gears then it kicks in and takes off. Not as noticeable in sport mode, hoping once I get my FP tuner installed some of this hesitation/lag will be eliminated…

ha, same thing here. The 1st to 2nd shift, EVERY MORNING, stumbles.

drives me nuts.

 

[wjtinfwb]

First.. background on me…. I’ve built a few v-8 engines for street and drag… tuned tubo rotaries in RX-7s and two carbureted 360 swaps into jeeps…. So.. this isn’t my first rodeo!!!!!

ANYWAY…

Just got our Bronco last week, black diamond 4 door with steelies and the 32”all terrain tires, I wanted the 2.7 all the way the 4 just seemed like it was wound too tight!!!

BUT……After a week and 400 miles, I’ve noticed that the engine isn’t as smooth as I thought it would be.

It’s not acting up (at least I don’t think so… but that The point of this thread.)

It idles kinda rough… especially at cold start….. I put high test in it and that helped a but..

It’s noisy, lots of belt noise and i swear it sounds like my Harley where you can hear the valve train, and there’s definitely injector pulse making itself known.. way louder in front of the car than our pacifica with the 6 cyl pentastar..

It’s lumpy…. At take off, if your not on the throttle hard, it kinda seems like you can feel each piston firing until you get up to 2k… From my turbo experience though, its not surprising, lower compression with no boost at low throttle and new turbos that are still tight tend to feel a bit lumpy….

I also know its tuned for torque and im not used to mud tires anymore….

My wife….. who knows nothing about engines except how to put her foot down…. Does hear or feel a thing!!!!!!! But me… i’m like…. Eeehhhhhhhhh i dunno!!!!!!

But……..I just wanted to know if this is all normal, or there’s anything i should be lookin out for!

Yep. My '23 BB Sas 2.7 reminds me of the early odd-fire Buick 231 V6's when they were in their first generation. Lumpy, kinda rough with a soundtrack that would make a Subaru flat-four owner proud. Mine sits in the garage for a couple days at a time so it's ice cold at start up. Sounds like it's got gravel in the crankcase! After about 30 seconds, the idle drops to about 900 and it smooths out significantly. On the road, I'd describe it's off idle response as uneven and abrupt. Really haven't experimented with the drive modes yet, perhaps that will help. I've got a lot of time in 3.5L EcoBoost Expeditions, they are much smoother and more linear in their off-idle response. Mine is coming up on 2000 miles and will get it's first oil change this weekend. Moving it to 5w-30 Full Synthetic, doubt it will make any difference but we'll see. I've also heard the Ford Performance tune both wakes up and smooths out the 2.3L, haven't heard any info on the 2.7 version. Otherwise, it's pretty impressive engine, very torquey, quiet on the road and mine is averaging a bit over 19 mpg in urban driving. It's also likely the Bronco just naturally offers less engine isolation than a F-150 allowing more of the engine "character" to sine through.

 

[Luthier419]

Yeah, same here, my 2.7 (2023 OBX) has about 3500 miles on it and it has noisy start up and lumpy idle - particularly at cold start up. Quiets down once warm, but still sometimes feel the lumpy idle. Don‘t recall my 2018 Raptor 3.5 being this noisy (in general) until the cam phasers went bad at 40k miles. Most frustrating to me is the hesitation when warmed up and lightly accelerating from a dead stop, just feels like it’s lost between 1st and 2nd gears then it kicks in and takes off. Not as noticeable in sport mode, hoping once I get my FP tuner installed some of this hesitation/lag will be eliminated…

Yeah, i’ve noticed some hiccups under light acceleration when just starting out,

if i was tuning my harley or an RX-7… i’d say it feels like surging because of a lean condition and would be looking at my Wideband O2 data log for 15 and up blips….
BUT… this is a new car under warranty…. Sooooooo I don’t think im gonna be installing my own O2 port just yet!!’

hmmmmmmm. In the turbo rx-7 case….. the solution was a fuel pulsation damper added to the end if the fuel rail to smooth out lean spots caused by pressure waves interaction that caused a pressure drop at certain injector loads and frequencies (think two rocks thrown side by side in a still pond)

 

[HotLap]

ha, same thing here. The 1st to 2nd shift, EVERY MORNING, stumbles.

drives me nuts.

You’d think after all these years of “throttle by wire” they’d have figured it out by now. Had a 2001 Lincoln LS with the 3.9L V8 (my 1st computer controlled auto) and it had the same issues…low end, light throttle acceleration and it had a horrible hesitation…like the various computer modules were making a “decision by committee“ on how to proceed. Worst was slowing for a red light that then turns green so at low speed you’d let off the brake and reapply the throttle and absolutely nothing for 1.5 secs, then a “BAM” and she’d be off again…

 

[ScLeCo]

My 2.7 doesn't do any of what you guys are describing.
I mean yeah it doesn't idle like butter but that's any primary imbalance V6.
The only nasty sound I hear is from the exhaust and that's just because I despise the sound of a V6.
I don't know but what some of you guys are describing sounds terrible and not something I'd want to live with on a daily basis.

 

[Luthier419]

My 2.7 doesn't do any of what you guys are describing.
I mean yeah it doesn't idle like butter but that's any primary imbalance V6.
The only nasty sound I hear is from the exhaust and that's just because I despise the sound of a V6.
I don't know but what some of you guys are describing sounds terrible and not something I'd want to live with on a daily basis.

Im betting that if you post a vid of starting up your Bronco with the phone in front of the car, we’ll be like, “yep”.

my wife doesn’t notice anything either…she knows cars.. she just isn’t as OCD as I am, nor is she as anxiety ridden, nor as micro detail oriented!

she’s like.. “MEH…. It sounds like a motor running”.

I’m like…. I just paid $50+K for a CAR…. I’m not really impressed with how noisy the motor is!

 

[Billnchristy]

A loud ass exhaust drowns out the horrible racket from up front.

 

[mpeugeot]

A loud ass exhaust drowns out the horrible racket from up front.

Yes, and cold start with a muffler delete is extremely loud compared to the normal idle. It's a particularly noisy engine when cold, but quiets down relatively quickly after it warms up a bit.

 

[cowman]

27. 11,00 miles smooth as silk since day 1....

 

[Billnchristy]

Yes, and cold start with a muffler delete is extremely loud compared to the normal idle. It's a particularly noisy engine when cold, but quiets down relatively quickly after it warms up a bit.

Apparently my wife set off my car alarm this morning starting up. It's the first time its ever happened. We have flowmaster Outlaw fx (by itself basically straight pipe) and a 12" resonator which quiets it a bit.

It's funny, the neighbor across from us has a chevy truck with exhaust, my bmw has a downpipe and her bronco with its setup and we all leave within 15 minutes of each other. I'm sure the others love it.

None of us are as loud as the guy down the street with the Barracuda though, that thing sounds awesome.

 

[mpeugeot]

Apparently my wife set off my car alarm this morning starting up. It's the first time its ever happened. We have flowmaster Outlaw fx (by itself basically straight pipe) and a 12" resonator which quiets it a bit.

It's funny, the neighbor across from us has a chevy truck with exhaust, my bmw has a downpipe and her bronco with its setup and we all leave within 15 minutes of each other. I'm sure the others love it.

None of us are as loud as the guy down the street with the Barracuda though, that thing sounds awesome.

My Flowmaster High Clearance Axle Back exhaust was a little bit too obnoxious for the girlfriend, but the AFE Apollo GT is about perfect, keeps her happy, but flows better than stock.

 

[Roger123]

Our 2.7 with 20K is similar to what you're describing. You just get used to it after awhile.

 

[Quicklime]

I'm just about to 20,000. I didn't feel like it was broken in until around 10,000. I have a history that includes operating paper machines as big as a small house. Tactile vibration feelings tell you a lot.

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