uneven engine vibration at idle

[whtchocla7e]

Does anyone else, with a stock car, experience uneven engine vibration at low idle rpms?

After a cold start, my car runs a little rough for a bit and then smooths out gradually.

When the engine settles below 1k rpm,I sit and listen for odd things and I can feel unevenness in engine vibration transmitted through the floor to my legs and the seat. No fluctuation detected on tach. I'm not talking about the CEL rough idle phenomena.


Could someone pay attention to this next time you get in the car and report back?

[mrk1]

Ive been noticing weird vibrations, both at idle and at constant highway speed.

[xwd]

Have you ever owned a Subaru before? The cars don't idle all that smoothly and some vibration is normal when idling. Vibration at highway speed is something different.

[theenglishmidget]

I've noticed this aswell. Never felt anything like this and I've owned an sti for years now.

[FR Sports]

I have the same experience with my car. It's not the smoothest idling engine. It feels like as if the engine skips a beat sometimes and I feel it through the chassis.

[jesperswe]

Mine does the same, worse when colder outside.
When the engine warms up it does not vibrate at all through the chassis. But on cold it feels like som old american v8

[mrk1]

Originally Posted by dwx

Have you ever owned a Subaru before? The cars don't idle all that smoothly and some vibration is normal when idling. Vibration at highway speed is something different.

Yup owned an STI for a few years.

[strat61caster]

Is your A/C or defroster on? That explains like 90% of the rough idle complaints.

[brz7400]

I feel it when idling sometimes, hope it's normal for a boxer...

[wes1202]

any updates on this ?

[Khazzy]

I believe everyone has this feeling. I asked the first time I sat in my car because it felt as if it was moving side to side. Much like slapping the left then the right inside the engine bay. I had never dealt with a Flat Four engine before and was always used to my Honda motor. Basically from what other people I know that own Subaru's, it is perfectly normal. I can only imagine the light weight factor of this chassis only exaggerates the motion of the Flat Four motor.

[strat61caster]

Originally Posted by wes1202

any updates on this ?

I've really started noticing it on mine over the past couple months (shorter commute, more stop and go while cold), seems like it's just a Subaru thing, you're not as isolated from the motor like most Honda's and Toyota's.

[Weeber]

Originally Posted by ae86stunt

I noticed it as well. So I hooked up my Snap-on Modus. Went to DTC Missfire Counter.

Sure enough. Its a random misfire for the first 30 seconds on cold start.
Fuel System is in Open Loop For 30 seconds or so.. Fuel trim is -1 Primary -1 Secondary.

So would these symptoms be normal? At least for the start up?

[Suberman]

Originally Posted by jesperswe

Mine does the same, worse when colder outside.
When the engine warms up it does not vibrate at all through the chassis. But on cold it feels like som old american v8

Flat four is balanced except for firing order. Just like a V8, the firing order imbalance causes a rocking motion. The boxer motor does indeed rock horizontally as every second cylinder fires. Only a flat 8 cancels these out. A flat 6 isn't as bad but still rocks (watch a 911 motor at idle. )

Flat crank V8 (think Ferrari ) are better balanced than normal bent crank V8 but still have firing order vibrations.