[JuiceQuadre]

Can Transmission issues be related to weak/alsmost dead battery?

So my AT is acting up a little bit.. I have 2006 E92 335D. a little bit of slip here and there, sometimes jerky shifting etc.. Its not horrible but sometimes annoying.

Also my battery is on its way out. Its just 2 years old but it got depleted totally twice and now shows only 11.5V when fully charged. Starts the car fine tho.

Iv read transmissions can be sensitive to weak batteries. Any evidence it could be the case with our cars as wel?? Anyone heard about it?

I was gonna buy new battery for the winter but now im paranoid that AT issues might be related to it.

[roadkillrob]

All kinds of crazy stuff happen with these cars when the battery is weak - total ghost in the machine stuff, so it is certainly possible that your transmission does some weird things with only 11.5V - car likes 11.8V anything lower and odd things certainly can and will happen. Might be unrelated and have not heard specifically of trans weirdness with low voltage, put certainly get a new battery asap 11.5V fully charged is pretty low and probably not going to last until winter - it should be 12.5-12.7 fully charged.

Also make sure you register the battery properly when replacing or you can have these same issues because of that.

[robygomez]

Originally Posted by JuiceQuadre

Can Transmission issues be related to weak/alsmost dead battery?

So my AT is acting up a little bit.. I have 2006 E92 335D. a little bit of slip here and there, sometimes jerky shifting etc.. Its not horrible but sometimes annoying.

Also my battery is on its way out. Its just 2 years old but it got depleted totally twice and now shows only 11.5V when fully charged. Starts the car fine tho.

Iv read transmissions can be sensitive to weak batteries. Any evidence it could be the case with our cars as wel?? Anyone heard about it?

I was gonna buy new battery for the winter but now im paranoid that AT issues might be related to it.

I was having some problems with my tranny with only 35,000 miles so I replaced the fluid and now it´s working as good as new. My car comes with the GM transmission and I used Pentosin ATF 1 when I took out the fluid it was pretty dirty cuase we are talking about a 7 year old car.

In my case that solved the hard gearing problems totally it´s an intirely different driving experience.

[JuiceQuadre]

Originally Posted by roadkillrob

All kinds of crazy stuff happen with these cars when the battery is weak - total ghost in the machine stuff, so it is certainly possible that your transmission does some weird things with only 11.5V - car likes 11.8V anything lower and odd things certainly can and will happen. Might be unrelated and have not heard specifically of trans weirdness with low voltage, put certainly get a new battery asap 11.5V fully charged is pretty low and probably not going to last until winter - it should be 12.5-12.7 fully charged.

Also make sure you register the battery properly when replacing or you can have these same issues because of that.

I guess ur right, no need to risk something else possibly acting up. I know about the battery registration.

Thanks

[JuiceQuadre]

Originally Posted by robygomez

I was having some problems with my tranny with only 35,000 miles so I replaced the fluid and now it´s working as good as new. My car comes with the GM transmission and I used Pentosin ATF 1 when I took out the fluid it was pretty dirty cuase we are talking about a 7 year old car.

In my case that solved the hard gearing problems totally it´s an intirely different driving experience.

My tranny has huge mileage on it so there is definitely some mechanical wear in play here as well.. My fluid has been changed 1 year ago so i dont think that would solve it now.