Transmission Problems

[insutantu]

1995 325i - 131K Miles - Automatic, original transmission.

The other day, I took off pretty quickly and the engine revved to around 5K, and I let off the gas and it would not shit up. Then, it knocked really hard and the transmission light came on and went into limp mode. I drove it for a bit then let it sit for a few hours, and drove it some. It now seems to shift fine going into second gear, but it will climb towards 3K RPM before shifting into third even when driving EXTREMELY slow. It will also lurch sometimes going into third. Also, the RPM gauge will sometimes stick at random places and not change.

Anyone have any idea what's going on? Thanks!

Also, in manual mode, it shifts better than my 2003 VW Passat did, so I have no idea what is going on...

[flyfishvt]

All I can offer is a story. I just got this Auto Vert a couple weeks ago. My previous e36 was OBDI and I was curious about how different sensor failure would get reported on my scanner so I hooked it up and disconnected the TPS, MAF and a few other common failure items.

I was surprised to look at the dash and see the tranny warning light was on. I scanned the tranny codes and found that some of those sensors also set a code in the tranny computer. I didn't drive it so I can't say how it would have reacted but your problem may not be tranny related.

Just wild shot in the dark here. Your RPM signal comes from the Crank Position Sensor. If your RPM gauge is acting funny then your tranny may not be getting acurate rpm readings. This could easily cause it to shift at odd rpm's and it could be you have a tranny code that needs to be cleared.

[insutantu]

Awesome, thanks for sharing!

How would I go about clearing or checking for codes? I do have a diagnostic cable that I used with my Passat for Vag-COM, but that software won't work on the BMW. Is there software I can download to use with my existing cable?

Thanks again!

[Spyke]

Not too sure if you could re-use your cable. Most of us use the Peake tool, or laptops.

[insutantu]

Well, the fuel pump went out and I got it replaced. The car is now shifting perfectly.

I took it to a mechanic where he checked for codes and what not. Could it be that the fuel pump was causing erratic shifting? Or, when he cleared the fault codes, could that of fixed it?

Just want to make sure this isn't going to come back, I just don't understand how the odd shifting could have anything to do with the fuel pump.