Change Trans Fluid...or Not
 

My daughter has a 93 E36 325i auto. Car has approx 200K on it. She gets intermittent problems where the Trans warning light will come on, and the car will start out in 2nd or 3rd gear, so she turns the car off, restarts, and all is fine. With this amount of mileage, is it worth changing the fluid?

This is a call for a good shop that can check it out. I have not heard of this particular symptom before, but it sounds electrical (solenoid valve problem) rather than mechanical. The only time my wife's automatic ever started out in a higher gear was when we accidentally bumped the manual mode button.

I would change the fluid and also the filter before doing anything else and see if it helps.

Pelican Technical Article: BMW Automatic Transmission Fluid Change

I would really like to change the trans fluid and filters, but I just want to make sure that will not cause more problems due to the mileage, and not knowing when/if it was ever changed, so you think it would be ok to change it?

I see no reason why it would cause any problems. Look at it this way, if it is the original fluid in the car, how effective do you think the filter is going to be? If clogged, it would impede the flow of fluid through the transmission, perhaps even causing the problems you describe.

Back in the 90's there was all the talk of "lifetime" oil in transmissions. How well did that turn out? Changing the fluid is a normal part of maintenance. It's a GM transmission, so you use Dexron 3 fluid. Many times, changing the fluid on these trannys made them run like new.

The key here is to make sure you get ALL of the old fluid out. I'd even recommend that you change the fluid, drive it for around 50 miles or so, drain the fluid and change the filter again to make sure you get ALL the old fluid (and possible sludge) out.

Follow the steps to re-fill in the article. Oh yeah, make sure your garage is well-ventilated. The stuff that comes out will probably smell awful.

Thx Jared, I'll change it.