Engine vibration

[alexsama]

Hello guys, a week ago I had bought a Fiesta 2017 Titanium 100CP from my ford dealer, the car had 15k km on it so I had a discount at it. Today for the first time I did open the hud and noticed how much the engine vibrates, is this normal? Thank you for your answers,

https://www.youtube.com/watch?v=WIqzL_rFc60

https://www.youtube.com/watch?v=0tXoSkc2rY4

 

[Rossyboi93]

have you ever looked under the bonnet. its not going to be still is it. with the power of the pistons etc going up and down and everything moving.

STUPID QUESTION if you ask me   

[fgservo]

My Fiesta 80hp with 3 cylinder shake that way too, but more from the side of the coolant reservoir, the rest is normal, scary me for a little while, but yours is perfect balanced, don't worry.

[Bobr]

First time I lifted the bonnet on mine I was amazed at how noisy it is.

[alexsama]

It's not really the noise I'm concerned, but more the vibration of the engine. From outside and the cabin the car sounds like a diesel, not really something I'm bothered out. Some people told me the same thing, that this is normal for 3 cylinders, however some told me that it clearly vibrates too much. I look into some other videos on youtube with the same engine and it doesn't vibrate that much. However, I have warranty 2 years so probably I will take to the service guys, however they might also tell me the same thing just no not get bother.

[Dan140]

3 cylinders will naturally have more vibration than a 4 cylinder that you are perhaps used to (you might have a dodgy engine mount if it's noticeably very bad but I doubt it on a 1 year old car). I was going to have a go at explaining why myself, but this article does a much better job and has nice graphics to illustrate the point:

https://www.carthrottle.com/post/heres-the-problem-with-three-cylinder-engines/

The key point is really the following:

"An inline three-cylinder engine is essentially a straight six engine lopped in half. Normally in a straight six, the two outer cylinders reach top dead centre (TDC) in unison, with the other four cylinders reaching specific angles of rotation to balance the primary forces, secondary forces and rotational torque of the engine nicely.

In a three-pot, piston one (the front piston) reaches TDC while the other two are 120 degrees away from either TDC or bottom dead centre (BDC). This means that the primary and secondary forces are balanced vertically, but the torque over the reciprocating pistons is not matched in unison like in an I6. Instead, the engine is trying to naturally rotate and flip over on itself. So to avert this, a balancing shaft is needed to counteract the twisting force.

The torque inbalance (shared with inline-five engines) makes for a rattling powertrain as the engine tries to rock from end-to-end, even when balanced as much as physically possible. This is due to the weight of the balancing shaft that the crankshaft has to work against, making these engines less free-revving than their more-balanced counterparts. Counterweights can also be machined into the crankshaft itself but they also add weight, decreasing its ability to rotate freely.

Also, due to the fact that ignition occurs every 240 degrees, the crankshaft journals are spaced 120 degrees apart. This means that there will be a significant proportion of crankshaft rotation (60 degrees) when no power stroke is occurring. That reciprocatory feature leads to the lack of smoothness in power delivery and large amounts of vibration that three-cylinder engines are notorious for. The rough-running engine behaviour will be emphasised at lower engine speeds especially, due to the lack of power strokes occurring."

[alexsama]

That was my initial tough also, I mean, how can an engine, not even 1 year old, even if it was driven inappropriate...can develop such issues so early, other than a factory problem.

Before having this car, I had a ford focus 2002 1.6 16v.

[James Drebin]

26 minutes ago, Dan140 said:

In a three-pot, piston one (the front piston) reaches TDC while the other two are 120 degrees away from either TDC or bottom dead centre (BDC). This means that the primary and secondary forces are balanced vertically, but the torque over the reciprocating pistons is not matched in unison like in an I6. Instead, the engine is trying to naturally rotate and flip over on itself. So to avert this, a balancing shaft is needed to counteract the twisting force.

The torque inbalance (shared with inline-five engines) makes for a rattling powertrain as the engine tries to rock from end-to-end, even when balanced as much as physically possible. This is due to the weight of the balancing shaft that the crankshaft has to work against, making these engines less free-revving than their more-balanced counterparts. Counterweights can also be machined into the crankshaft itself but they also add weight, decreasing its ability to rotate freely.

Well you learn something new every day. That was actually rather interesting! :-)

[Dan140]

8 minutes ago, James Drebin said:

Well you learn something new every day. That was actually rather interesting! :-)

Indeed! There's a lot more to 3 pots than simply chopping a cylinder off. The ecoboost is actually remarkably refined given the above, ford really did a good job with it. It's also interesting that to counter the vibration they usually have to use a heavier flywheel on 3 cylinder engines. One of the complaints I've read about (and experienced) is a tendency for the 1.0 to hold onto revs when changing gear at high rpm, and this is the reason why.

[James Drebin]

2 minutes ago, Dan140 said:

One of the complaints I've read about (and experienced) is a tendency for the 1.0 to hold onto revs when changing gear at high rpm, and this is the reason why.

Ah yes, I've noticed that too. The whole engine is a friggin' miracle though - I really can't beleive how quiet it is, even when driving angry. 😄

[Bobr]

47 minutes ago, Dan140 said:

It's also interesting that to counter the vibration they usually have to use a heavier flywheel on 3 cylinder engines. 

I don't think the Ecoboost uses a heavier flywheel.   My understanding is that Ford unbalanced the flywheel to match the unbalanced pots and removed the balance shaft.

[sioneon]

1 hour ago, Dan140 said:

One of the complaints I've read about (and experienced) is a tendency for the 1.0 to hold onto revs when changing gear at high rpm, and this is the reason why.

Yeah it's hard to get uesd to. Flooring it in third and getting up to 60 you have to wait a few seconds before you put it into 5th, even going into 4th before 5th makes a little hop

[ThaiFiesta]

1 hour ago, Bobr said:

I don't think the Ecoboost uses a heavier flywheel.   My understanding is that Ford unbalanced the flywheel to match the unbalanced pots and removed the balance shaft.

That was my understanding also

[Dan140]

1 hour ago, Bobr said:

I don't think the Ecoboost uses a heavier flywheel.   My understanding is that Ford unbalanced the flywheel to match the unbalanced pots and removed the balance shaft.

Yes you are right. I guess the addition of counter-weights to unbalance it makes the flywheel slightly heavier than normal but not clear if it's the additional weight or the inherent unbalance that is the cause of the rev holding. In any case, some more info on how Ford engineered the 1.0 and overcame some of the engineering challenges with a 3 cylinder here, interesting read!

http://www.wardsauto.com/technology/ford-s-3-cyl-ecoboost-delivers-goods

[alexsama]

I did follow the discussion, however I'm a little nervous about it, I recorded how the car sounds from outside near it, and afterwards in the cab. It sounds like an old diesel engine.

 

 

 

[pedro1886]

My engine does vibrate in the bay a bit. 

Can't feel it in the cabin and the idle isn't rough

Popped the bonnet a few days ago and noticed it

[pedro1886]

 

 

[alexsama]

Yeah, seems to have the same behavior as mine.

[Dan140]

Just to chip in - got the bonnet up on mine after a drive today and it sounds the same as your recording, so think you’ve nothing to worry about - just the nature of the engine!

[alexsama]

The sound is not really something that bothers me off, just the vibration of the plastics near the engine itself. Maybe I'm little too worried. From what I saw here and in another resources, some engines have the same 'bad' vibration, some and mostly don't (which I checked in real life),  even if they are the same 1.0 EB, which is strange for me. If this will be good or bad, only time will tell. Thanks for your answers.

[James Drebin]

I've listened to both videos from @alexsama and @pedro1886 and I don't think either sounds like anything abnormal. Admittedly Pedro's is obviously louder as he's got the bonnet open, but the amount of motion looks normal to me. Yes, there is a slightly more noticable ticking sound with it than on mine, but that could just be my perception.

If either of you are really worried, perhaps you can ask a trusted (ideally main dealership) mechanic/experienced rep to just listen to it to see if it rings any alarm bells for them. If they want paying, then don't bother, but if they'll lend you an ear for free (which they really should), it can't hurt! :-)

[Trewithy]

Coming from a Japanese car I was really aware of the vibrations especially at tick over, once on the move it didn't bother me as it is smooth once it gets moving.  However I found out that by using a higher octane fuel the engine became much smoother and quieter so now I run on Tesco momentum 99 and find it nicer to drive.  Another advantage is a slight improvement in mpg.

[cjay1]

I've just tried the ecoboost on tesco momentum. Found no difference for the first 100 miles or so. Since I've noticed a slight mpg improvement and smother running ( 1300 rpm grumble gone). Will give it a couple more tanks before deciding whether to use it over standard 95

[alexsama]

I tried 100 fuel, however no difference. A quick update: I was to the dealership today to do my first revision, after that, we tried over other fiesta's that were in the courtyard to see how the engine is running. Unsurprisingly, even they acknowledge that my engine vibrates more than the other fiesta's, they inspected a bit under the hood, however they couldn't tell me if it's something good or bad about it, told me that it is is as it is, and they can't do something about it because nothing seems wrong about it besides this inconvenience.

[ThaiFiesta]

Have you checked that all the engine mounts are serviceable?