vibration in valvetronic...

[beem]

Hi all sifoos.....

There's been this slight vibration that seems to be rythmetic on my valvetronic during idling and D is engaged. Also, does ppl driving at speeds of 140km/h above feel that the engine vibration is transferred to the steering? Normal?

I have just serviced my car and the vibration seems to be strong to the point that my idling seems to jump up and down sometimes...changed my engine mounting..nothing seems to fix it...

All said, my mech told me that my cylinder 4 is not "cycling" within specification. I forgot what is the righ term for this but i remember he showed me the specs should be

 

[piggyboyz]

Re: vibration in valvetronic...

First off, is this slight vibration you mentioning not there and only developed recently ? Also, how old is the car ? this may help in determining the cause of it.

Depending on what is your the definition of slight vibration, all 4 cyclinder engine will vibrate more than a 6 cyclinder engine.

What your mechanic is trying to tell you is that the 6 cycliner engine is more balanced since at anytime, there will be 2 cyclinder firing, 2 at exhaust phase making it balance, hence smooth.

Comparing a front wheel drive and a rear wheel drive, the RWD car will vibrate more since the engine is mounted longitudinally and the rock due to the crank movement while it is spinning is transverse (left / right) and that will make it more pronounce than mounted the other way.

The common problem for vibration in the N42 engine will be the idle valve, which will cause occasional engine hunt or the ignition coil.

But if the vibration goes all the way to 140kph, then i supposed it's more likely to be worn bushing and I suggest u take a look at things like your control arm bushing or your engine mount, which are the main culprits for vibration in the cabin. Do be aware that a unbalanced tyre will cause vibration at high speed also

Cheers..

 

[beem]

Re: vibration in valvetronic...

The slight vibration is always there..not sure why does it gets worse over time (ie: more frequent)....especially after the recent oil change. My car is registered Nov. 2002.

During idling when D is engaged (ie: stuck at a traffic light), especially during a complete stop after a high speed run, I can feel like my seat is vibrating, together with the steering. But the vibration is not terrible but a mild one. Feels like u are sitting on a dampened OSIM chair.

As you said, its a common problem. I have had all my coils changed. Guess that's not the issue, maybe its the idle valve...but you can only service it right?

I got feedbacks from other mechs that the air hoses around the car needs to be replaced...but replacement will temporarily solve the issue..not eliminate it.. Another mech says the "intake separator" just underneath the exhaust or intake manifolds needs to be changed.

Any idea on what's the cylinder number thingy?

Also, the vibration does not go all the way to 140Km/h. Only at speeds above 140Km/h, i can feel the vibrations on the steering..just the steering...some high frequency vibration..doesn't seem to be a tyre balancing issue..wondering if its the control arm or bushing...

 

[morphisis]

Re: vibration in valvetronic...

I think it maybe the front control arm bush... because mine is worn... and i am having the same thing.. once over 140kmh.. vibration or shaking is felt... or even when braking or coming to a stop, the steering will shake...

maybe you can just go and get it changed... i havent changed mine as i am seldom gng above 120kmh... but have to get it soon, since its already worn....

Cheers...

 

[CSS]

Re: vibration in valvetronic...

I think the vibration at idle and that at 140km/h are due to different problems. My car E46 valvetronic developed vibrations when stationary and at D, replaced vacuum hose at PML under warranty (it's a v cheap item) and everything is back to normal. The vibration at higher speeds would be as mentioned by the rest may be due to wear and tear items eg. the front control arm bushings.

 

[beem]

Re: vibration in valvetronic...

Where is this vaccum hose located?