BMW X5 4.4i Transmission lags or slips

Time for a transmission rebuild

Odd question

You have a vehicle barely 6 years old with
a failed transmission & now can not use it at all

Once they slip your done
Has to be rebuilt

Did you not change the fluid ever 3 years?

That may cost you $3500 verse $80 for a fluid
change 3 years ago & again now

Can't change it now it slips,it will get worst

Sounds like your transmission has come to the end of its life. You can try getting the transmission flushed , and an additive I.E. No Slip added. That might cure some of the problems but obviously if its slipping the clutchs inside are worn out and transmission needs an overhaul.

If the transmission seems to be slipping, check the fluid level for the automatic transmission.

If the engine stalls on acceleration, the tps or throttle position sensor may be bad, or the engine is in need of a tune up.

to check oil start vehicle in park and let idle, open large allen bolt [normally 17mm] on g/box sump, oil should spill from aperture. if not top up until it does. this must be done at a temperature of less than 30 degrees celsius as oil expands at higher temperatures.

the computer may be making the transmission shift into low gear this would make it seem like the transmission is slipping

sounds like you have slipping clutches in the transmission , it needs to be overhauled

its either low on fluid or the clutches & bands are worn or need adjusting!
DONT REV IT!
get itserviced QUICK SMART! & check for leaks!

If your engine is getting hot, check your radiator for transmission fluid; the radiator has a small heat exchanger that cools the transmission fluid it is located inside the radiator bottom; the transmission lines attach there; also, the leak into the radiator of transmission fluid can "starve" the transmission causing delay in shifting, slipping and, more throttle being needed to engage and, shift.

Putting it in four wheel drive does not eliminate the transmission. Honestly, it sounds like the transmission is on it's way out. A 4l60e in one of cars was acting the same way. It required a rebuild.