I have a '90 740 turbo i bought recently. I'm having trouble with the tranny. The fluid is clean, but it seams to stay in gear too long when it shifts then it shifts a bit hard. it'll cruise at 50 mph at about 3000 rpm. It's not really even too big of an issue, but it is quite annoying.

ALSO I believe the engine is running a bit rich, but nothing to major. There was a bit of crud in the tail pipe. The o2 sensor may be to blame, how can i check before replacing it?


any and all replies are welcome. Thanks All

Justus

I have tried to change the kick down cable. I only moved it 1 16th of an inch or so. I will adjust it more this weekend. (my father borrowed the car) But it was pretty tight. Now thinking about it.. I adjusted (tightened) the throtle cable and it DID assist in loosening the kickdown which did smooth it a bit. SO, in turn, i do feel this will correct the issue to a great extent. The fluid is clean.

Thanks ALL for your assistance

Justus

Justus: What Chris is referring to is also called the 'kickdown' cable, which has a disc of its own, right next to the throttle cable; the kickdown cable comes off of that disc. or spool, horizontally, rearward, toward the driver. What is exposed (bare cable) is about 4 to 6 inches long. just behind it, towards the driver, is a nut assembly, for adjusting its tension. it should LOOK like its held straight/flat, but it should NOT be as taut as a piano wire or guitar string: it should just the slightest bit of looseness to it, and you should be able to pull it sideways (=toward you) about 3/4 of an inch: pull it, let it go, it should 'snap' or 'click' when you let it go. If it is looser than that, tighten it. PRAY that it's not the other end of that cable, which is inside the tranny bell housing, and is a B...H to attach if its not in there correctly (it's a 3-handed job in a space where NO hands really fit). Also, the fluid may be clean, but could still be old. If it's been a while since you did a tranny flush, try that, too...hey! give that to your car as a holiday present! Some folks swear by Amsoil, others by other synthetic, and some prefer the VoVo atf: whatever floats your boat.--PD.

It might also be the little blue plastic ball in the trans htdraulic brain. Check the 700/900 FAQ via the 'features' pull down menu.
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Warren Bain - '86 744Ti M46 >282Kmi, '96 965 >97Kmi Wifemobile near Manassas Va

It sounds like the transmission shift control cable is binding. That's the one that goes from the throttle spool to the transmission. There are instructions in the 700/900 FAQ for checking it out. That is typically the problem with the sticky shifting (and delays cause hard shifts under light throttle with the AW transmissions).

I'd check the fuel pressure regulator for leakage too, if you're looking for rich mixture issues. Is the diagnostic unit giving you a code that indicates a rich mixture?

With the turbocharger, you might be seeing a little bit of oil residue or unburnt fuel. The turbo's pipes usually are a little bit on the dirty side after some miles, as compared with the naturally aspirated engines. The tailpipe doesn't indicate mixture problems necessarily. I wouldn't worry about that, or the 02 sensor unless you're having specific problems and a code from the engine computer that indicates trouble.
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Chris Herbst, near Chicago, IL. 93 940, 91 240, 90 240, 88 740, 87 240