Slight vibration going uphill under acceleration

[Craigito]

I climb a few pretty good grades on the toll road to and from my work. Around 6% max. I notice under heavy load I get this very light shimmy in wheel. More annoying than anything. I get absolutely zero vibration when going downhill on these same grades. Wondering if its just the tires? It doesn't feel like the engine. Anyone else notice this?

[AndyLu]

Downshift to go up hill. Putting too much on the transmission so it shutters

[Craigito]

Originally Posted by AndyLu

Downshift to go up hill. Putting too much on the transmission so it shutters

Im in a lower gear over 4k rpm doing this.

[dch37]

over 4k.. wheel-slip maybe... try aroun 2k rpm

[KL07RPH]

Have you noticed it at a particular speed or range? Might be tires if so. Another possibility might be the road too (i.e., the sucky 60 fwy w/ it's rythmic "thunk a thunk a thunk").

BTW I remember your awesome 335i ED thread on Bimmerfest! That is all before it got misplaced on redelivery lol.

[badbimmer]

Originally Posted by Craigito

I climb a few pretty good grades on the toll road to and from my work. Around 6% max. I notice under heavy load I get this very light shimmy in wheel. More annoying than anything. I get absolutely zero vibration when going downhill on these same grades. Wondering if its just the tires? It doesn't feel like the engine. Anyone else notice this?

No, my suggestion is that you should drive up hills backwards in reverse. That should help.

[F82TT]

Originally Posted by Craigito

I climb a few pretty good grades on the toll road to and from my work. Around 6% max. I notice under heavy load I get this very light shimmy in wheel. More annoying than anything. I get absolutely zero vibration when going downhill on these same grades. Wondering if its just the tires? It doesn't feel like the engine. Anyone else notice this?

could be a wheel balance issue.. try having them re-balanced. its cheap and worth a shot as tire balance over time with tire wear will change.. ive even had new cars come with wheels needing to be re balanced. who knows maybe the way the strap them down when shipping.. also depending on how many miles are on the tires and how hard you drive, tires over time especially if run HARD/ track/ auto-X or spirited street driving can ridge slightly causing a small vibration under certain conditions. its happen to me on both my 911 and my M3 in the past.. new tires and OR a high speed balance and it was fixed both times..

also driving with the wrong tire pressure over time can cause these symptoms..

[bmrwrld]

Don't be afraid to put the foot down, it will clear that problem.

[M4Now!]

Yes, I have a slight vibration under hard acceleration, more like a thrumming, mostly in the midrange. In lower fears. Hasn't ever bothered me, and not felt in any other situations.

Cheers

[MSport_Jon]

after a had differential and drive shaft replacement, BMW left me with this same problem as a nice surprise and to top that off, they say it is normal when clearly it was not there before the replacements...


not sure how yours is but mine is after 3rd gear and med to heavy acceleration and going up a hill. Also, and this could be my imagination but the problems seems more pronounced if the car is used for prolonged amounts of time say 1-2 hour drive. It does not do any of this if you are going down hill and it is silky smooth...

[DanMpower]

I think it's normal, under heavy load in certain parts of the rev range around 3500-5000 I feel a slight vibration in the wheel as well, doesn't happen all the time but sometimes. Almost feels like active blind spot/lane departure vibration, just to a lesser degree. Same thing in my friend's M4 so I assume it's normal. I just chalk it up to extra character from these M cars.

[MSport_Jon]

Originally Posted by DanIAM3

I think it's normal, under heavy load in certain parts of the rev range around 3500-5000 I feel a slight vibration in the wheel as well, doesn't happen all the time but sometimes. Almost feels like active blind spot/lane departure vibration, just to a lesser degree. Same thing in my friend's M4 so I assume it's normal. I just chalk it up to extra character from these M cars.

yeah... you are right almost feels like it .... it sure feels like shit though... no very confidence inspiring...

[rarlyl8]

Start simple. Tire pressure then move onto tire check for wear and the balance all four.

[MSport_Jon]

Originally Posted by rarlyl8

Start simple. Tire pressure then move onto tire check for wear and the balance all four.

been there... done that... back in square one... BMW says it is normal... i think its shameful that they are proud of such inconsistency...

[MSport_Jon]

Calling on all members who are experiencing this problem.


I strongly believe the drive shaft is the problem... the CF drive shaft does not have a center support device like the steel shaft does and it seems CF drive shafts are affected by moisture as well as temperature. I discovered on my car that when going down a steep long decline and braking with the engine on third gear, when i get o the bottom and stop and the ground levels, when i accelerate moderately to heavy, i no longer feel the vibration for a while say 5 or 10 minutes and slowly starts to show up. Also happens if i leave my car parked on a steep hill first gear and nose elevated up the hill for a while say a few hours, i no longer feel the vibrations for a while.

because of the lack of center support on the drive shaft, i believe that if there is a minuscule amount of bend, at high speed it will multiply in force and frequency and hence can be felt. When applying a counter force such as engine braking where the twist is opposite to the engines torque direction, it seems to bring the CF driveshaft closer to its initial spec and hence no vibration. again this is all speculation on my part... For anyone that has seen CF drive shaft from BMW. it truly looks like a 5 year old put it together.




here is a example of a third party manufacturer CF drive shaft


i tell you, for those 5 - 10 minutes the car feels soooo good!

Please try this and post your observations...

[Imperial328i]

Originally Posted by DanMpower

I think it's normal, under heavy load in certain parts of the rev range around 3500-5000 I feel a slight vibration in the wheel as well, doesn't happen all the time but sometimes. Almost feels like active blind spot/lane departure vibration, just to a lesser degree. Same thing in my friend's M4 so I assume it's normal. I just chalk it up to extra character from these M cars.

Do you still have your car? If so has the issue gotten worse?