[E92William]

Recently checked out my friends Lexus SC300 with a naturally aspirated 2jz toyota 6 cylinder. Upon popping the hood I always like to lay my hand on top of the engine to see how smooth its idling and running overall. This engine was barely even shaking you couldn't tell it was on. I've seen this a few times with toyota 6 and 8 cylinder engines.
I've owned plenty of bmws from e90 325i to e92 335i to 328s and never have I felt any of them be so smooth at idle. They always have a very slight bit of vibration.
Is there any explanation as to why BMW sixes are not as smooth as old Toyotas with a zillion miles?
I currently have an e92 328i no ticking no misfire no nothing no codes at all scanned with ista. It's always been that way and all of them have.

[S65Hunter]

It's just a toyota/lexus thing, smoothest engines out there man.

[Leucosticte]

really? I've found my N52 to be smoother than the v6 in my parents rx 350

[Antetokounmpo]

Originally Posted by kakapo

really? I've found my N52 to be smoother than the v6 in my parents rx 350

V6s inherently aren't as smooth as an inline six due to the i6 having near perfect primary and second balance.

[Emilime75]

I've got a 95 SC400 project car with the 1uzfe, 4.0 V8 with around 230k on it. It idles around 550-600 when warmed up and it's the smoothest idling motor I've ever experienced.

[mecheng77]

The in cabin feel of the N52 is amazing smooth, once warmed up. To obtain perfect smoothness may require a downgrade in power to perhaps adjust timing; or some other factors. I know Lexus bragged about how smooth their LS400 engine was with champagne glasses; thats not what BMW is after.

You can also dampen a lot of vibrations with softer engine mounts, but this hurts the performance feel.

[PichaDis11]

Aren't both engines mounted at different angles? Wouldn't this be an effect?

[nsjames]

Originally Posted by mecheng77

The in cabin feel of the N52 is amazing smooth, once warmed up. To obtain perfect smoothness may require a downgrade in power to perhaps adjust timing; or some other factors. I know Lexus bragged about how smooth their LS400 engine was with champagne glasses; thats not what BMW is after.

You can also dampen a lot of vibrations with softer engine mounts, but this hurts the performance feel.

I can't even feel my engine at idle and I've sometimes hopped in a running car and turned it off.

[iqraceworks]

Engines can develop harmonic frequencies at different RPMs. You might have two motors that are both "balanced"....but one might have been balanced at a different rpm then the other. Or might have more of a vibration at idle than the other one........or might be more "rigid" and not develop the same harmonics at idle, or might (or might not) have a different valve train design that transmission harmonics into the motor.....

Vibration at idle wouldn't really concern me.......vibration at 3,000+ rpm is what matters. I know my N54 has a little bit of vibrate at idle.....but at 2,000rpms it's so smooth, it's like it's not even running.

[E92William]

The 1uz in an sc400 I went to check out was like it wasnt even running. Super smooth. Same thing with the 2jz. Maybe there's something going on indeed with the angle the engine sits at and how that transfers vibrations into the mounts. Or the mounts used in the toyota engines. Still intrigued.
Also relatable as sometimes I've almost left my car not realizing the engine was on because you can't feel or hear it inside the cabin

[Emilime75]

Mine's staright piped except for the stock cats, don't have a problem leaving the car without realizing it's running... but I could see how that could happen with the stock exhaust.