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-   -   Bizarre Reverse Issue (http://www.bimmerfest.com/forums/showthread.php?t=663385)

jeaux 12-11-2012 04:55 AM

Bizarre Reverse Issue
 
Hi Everyone!
My 1993 5351 (177k) needed a jump because I carelessly shut the trunk lid and it didn't shut all the way and the light stayed on and ran down the battery. I couldn't get it jumped until the next day, and it started right away, it hadn't completely run down as clock had the right time.
As I put it into reverse, a strange thing happened! It felt like I was blocked by something! The highway assistance guy thought my parking brake was on, but no, and he ended up having me put in neutral and pushed me out of my parking spot so I could get home. On the way home at red lights with no one behind me it had no problem going into reverse!
The same thing happened the next morning....and has intermittently continued, once it is warm there is no problem.
I was stuck at work a couple of days later in the garage (it did it again) and I called the shop where I go and they talked me through checking the trans oil level, and it seemed very low although the car was cold. A guy at work gave me some fluid, we put some in and instantly it reversed JUST FINE! I then drove to the mechanic to check it, who said I am now overfilled, and they think the problem would come back tomorrow. BUT WHY? I think it must be an electrical issue since it occurred right after the jump, but what do I know?
So, there was no problem for a couple of days, but now the problem is back again. I can indeed slowly and painfully reverse, then drive and in a few minutes it shifts into reverse as pretty as you please. Sorry for this long explanation, but anyone have any ideas as to what is going on? THANKS so much!

snowsled7 12-11-2012 05:03 AM

The transmission is wearing out. Make sure you have the fluid level correct. The trans will not work properly if the fluid level is incorrect.

I don't usually reccomend doing a service on a failing trans because... they end up failing most of the time anyway. That is why you see people reccomending not to flush an old trans. They do not understand that them failure had already occurred, and the flush was a waste of money. You can do a fluid and filter swap though again, unlikely to fix it.

Sounds like a good time to start collecting parts for a manual trans swap;)

jeaux 12-11-2012 05:11 AM

Thanks snowsled for your thoughts, but how depressing for me!.
Why though did this 'failure' not manifest before I had it jumped, it shifted up and down the SF hills as smooth as silk!
And btw it's an automatic....is that relevant?

snowsled7 12-11-2012 05:23 AM

I suspect the jump start and the trans acting up are not related at all, just coincidence.

Doesn't sound like a shifter issue if you were able to select neutral. I guess it is possible something electrical was cooked in the jump. Reference the Bentley manual, I am not completely familiar with the auto trans on these cars.

I knew yours was an automatic because manual transmission cars do not have those kinds of failures:angel:

jeaux 12-11-2012 04:28 PM

Thanks snowsled. Same thing happened today, hard to reverse at first, car warms up and it reverses just fine. So strange.

BMR_LVR 12-11-2012 05:10 PM

Quote:

Originally Posted by jeaux (Post 7243774)
Thanks snowsled. Same thing happened today, hard to reverse at first, car warms up and it reverses just fine. So strange.

My previous 92 E34 did the same thing at 256K miles. It was not long thereafter before reverse went out completely. I hope yours is something less serious.

robertobaggio20 12-11-2012 05:10 PM

Quote:

Originally Posted by jeaux (Post 7243774)
Thanks snowsled. Same thing happened today, hard to reverse at first, car warms up and it reverses just fine. So strange.

Well, for what its worth, read your error codes, and then delete them, and see if it helps.

And snowy, please enlighten us on what would happen if the transmission is overfilled with oil, if you have a few minutes.

BMR_LVR 12-11-2012 05:29 PM

Quote:

Originally Posted by robertobaggio20 (Post 7243842)
Well, for what its worth, read your error codes, and then delete them, and see if it helps.

And snowy, please enlighten us on what would happen if the transmission is overfilled with oil, if you have a few minutes.

I continue to see you tell people to pull their codes relating to transmission problems. I have reviewed the code list for the stomp test and don't see any relating to the transmission; just the engine.

Please enlighten me/us as to how to pull codes for the transmission and what the codes to look for are.

Thanks.

jeaux 12-11-2012 06:12 PM

yes! please tell this girl how to 'pull codes' and what happens if trans oil is 'overfilled'. I am eager to learn how to keep from being a full time pedestrian again. What do you think of Lucas transmission product? Would it be something worth trying at this point? Thanks to all...

robertobaggio20 12-11-2012 07:09 PM

Quote:

Originally Posted by BMR_LVR (Post 7243880)
I continue to see you tell people to pull their codes relating to transmission problems. I have reviewed the code list for the stomp test and don't see any relating to the transmission; just the engine.

Please enlighten me/us as to how to pull codes for the transmission and what the codes to look for are.

Thanks.

There are the trans program errors, and there are errors related to the solenoid valves and adaptive transmission feature in the gearbox. I have seen these through code readers and some of them on posts as well. They may not all be in the manual but as we all know, the manual is not exhaustive, always user friendly, and sometimes does make errors (which may manifest as ommissions as well).

My greater point when it comes to pulling codes is to (a) see what codes have appeared in the first place, and there may be stuff you wish to see, code pulling if your car allows it should be the first step in diagnosing anything, and (b) delete the codes either via the stomp test or by unplugging the ecu, because that works many times.

As we have seen on many occasions and as I have noticed on my own car, codes which cause problems often disappear and stay away permanently along with the problems they came with. This was the case recently on my ride with the ect...i had bad fuel economy suddenly, read the codes, ect, deleted the codes, fuel economy normal, no repetition of codes. Perhaps the component was only transiently defective, perhaps the car was having a bad day, perhaps the code would have gone away after 60 starts with no trouble, perhaps we just got lucky that the codes stays away. I'm not sure.

Nevertheless, its another simple method to use to deal with anything related to the car that has proven its worth often enough to be in the quick and dirty list. Reading and noting codes and deleting codes via the stomp test or through unplugging and refixing the ecu after a few minutes in any case takes just 10-15 minutes in total so its a painless procedure.

OP, please check out the maintenance sticky thread at the top of these forums for more information on the stomp test and how to execute it on your car. There are also good explanatory videos on youtube about this. Furthermore, please search for and download the Bentley manual for E34s and check the section on transmission servicing. And its good that you're a girl....check out the old bmw commercials on E34s on youtube. :)

I personally don't know if there are any adverse consequence of overfilling the transmission, which is why I asked snowy about it. Of course, if you underfill your transmission, you can expect a whole host of problems, most of which will go away after you fill it up properly.

If you have filled up your transmission and your issues stay away thus proving that low fluid was the problem, you gotta check to see if you have any leaks anywhere. This is very important.

Snowy's point in reply to you is correct. Oftentimes, problems with the car coincide with other problems or their resolutions. They are not related or triggered by the earlier issues. It may take some sleuthing to figure that out. Regardless, whenever I have a problem that happens to come along due to another fix or a problem, I work on the initial assumptions that they are related.



rgds,
Roberto

robertobaggio20 12-11-2012 07:16 PM

Quote:

Originally Posted by BMR_LVR (Post 7243840)
My previous 92 E34 did the same thing at 256K miles. It was not long thereafter before reverse went out completely. I hope yours is something less serious.

It could be the solenoid that controls the reverse gear shift that is busted. New solenoids run you about $50-$100. The service to fix it would be related to removing the valve body and replacing the solenoid, which is similar to replacing a large battery. I believe bmw dis should be able to read if the individual solenoids are alive or dead. Not sure about the stomp test....in fact, from what you say earlier, the stomp test has no tranny codes.

I am of course speculating here, but it does not seem to be a gear or clutch defect if the reverse gear goes out suddenly. The solenoid concerned has to redirect oil pressure appropriately to shift gears (loosely speaking) when required. If the solenoid is dead or defective, you either experience a hard shift or no shift.

Another possibility is a defective transmission range switch. That would be the low hanging fruit. However, that is usually not the case, but its worth checking anyway, just in case..

OP....please delete all of your error codes, preferably by unclamping the ecu for a few minutes. If that doesn't fix the problem (and since you've got enough oil), you probably do have to visit a tranny specialist.



rgds,
Roberto

BMR_LVR 12-11-2012 07:17 PM

Roberto, I think you misinterpreted the tenor of my question. I was not asking sarcastically but seeking information. Take it as you will. I have just never seen codes for transmission problems that could be obtained by a typical owner, especially via the stomp test, of which you have instructed multiple people multiple times.

I'm sure that BMW dealers and/or higher level independent BMW mechanics have a computer system that can query the TCM for codes. I just thought you knew of a code check for the transmission that I was not aware of.

jeaux 12-11-2012 09:18 PM

Wow there is a lot of brilliance on this forum! I plan to carve out some time to read, re-read, and make practical application of your thoughtful responses! Exciting! But...any thoughts about Lucas trans fluid stuff?
I will let you know what I find out when I do these diagnostics...I am determined to get to the bottom of this mystery! Thanks ever so much!

robertobaggio20 12-12-2012 01:23 AM

Quote:

Originally Posted by BMR_LVR (Post 7244187)
Roberto, I think you misinterpreted the tenor of my question. I was not asking sarcastically but seeking information. Take it as you will. I have just never seen codes for transmission problems that could be obtained by a typical owner, especially via the stomp test, of which you have instructed multiple people multiple times.

I'm sure that BMW dealers and/or higher level independent BMW mechanics have a computer system that can query the TCM for codes. I just thought you knew of a code check for the transmission that I was not aware of.

Steve sir, I apologise if I came across as being too defensive. You know that I will sic Bentley's ghost on anyone who dares to offend me, so you wouldn't dream of it. :) In truth, I don't personally like the process of fixing problems by deleting codes. Its too much of a chance factor for me, and even when it does work, sucks, because it shows that the car has weird mood unexplained mood swings etc.

To clarify, there are indeed transmission codes, whether they appear in the stomp test or not. They can be seen on bmw dis and peak readers (and probably carsoft too). I don't know of any other way to extract or derive usable transmission codes at this point.

Sometimes, merely deleting codes fixes a problem, especially one that seems to be unprovoked by any specific action/inaction. Before deleting the codes, they should be read and noted down in case useful information is present. After codes are deleted, the codes should be reread a few days later after some driving in between to see if any codes that appeared earlier are repeated. Codes that are repeated deserve scrutiny and action if they are judged to be important.

Codes should be one of the first things to be pulled in the process of diagnosing or gaining visibility on anything, as they are too easy to do if the stomp test works on one's E34. I forget this too often in my recommendations and so I try to start off with this one first nowadays.

As an aside, I just encountered an android friendly bluetooth OBD2 code reader adaptor on ebay ! The adaptor connects to the car and interfaces with the smartphone through the bluetooth receiver on the phone. The phone has a free downloadable software that can display codes. Hot stuff man !!! Unfortunately they don't seem to have an OBD1 version but I'm positive that its just around the cornere.

snowsled7 12-12-2012 04:56 AM

Your transmission is dying. You have classic symptoms prior to completely losing reverse. Accept it, plan for either a rebuild or a used junkyard trans. This is quite common on auto trans cars of this age.

Overfilling the trans usually only results in the fluid exiting the dipstick tube and making a mess, or leaking from the trans pan seal, making a mess. It is unlikely to harm the trans. I do not know the proper procedure on these cars, mine is a manual. Some models have no dipstick and require you to remove the drain plug while running:dunno: Point being, just make sure it is correct per the manuals procedure.

I would not bother with mechanic in a bottle. It will not fix the problem. You have an impending trans failure, probably a broken reverse band.

robertobaggio20 12-12-2012 05:12 AM

Quote:

Originally Posted by jeaux (Post 7243995)
yes! please tell this girl how to 'pull codes' and what happens if trans oil is 'overfilled'. I am eager to learn how to keep from being a full time pedestrian again. What do you think of Lucas transmission product? Would it be something worth trying at this point? Thanks to all...

These tranny treatment products may help with hard shifting and clutch slippage. I don't think they will help with this situation.

BMWFatherFigure 12-12-2012 06:49 AM

Bottle fixes are done just B 4 you sell the car

jeaux 12-12-2012 06:09 PM

Hello friends!
Again this morning a tough minute or two of reverse and then reverse as smooth as silk. I have an appointment with Hans' german car shop to check and clear all error messages, only 70$ and seems like a place to start. Autozone won't do it in California (heard that they do elsewhere).
I am curious...if indeed the tranny is failing, and I realize that is a real possibility, then why the symptom only when the engine is cold? What is the science behind that phenomenon?
Thanks again...this is really kind of fun.

snowsled7 12-12-2012 06:14 PM

Cold fluid pumping losses requiring more time to build the pressure needed to engage the gearset.

jeaux 12-12-2012 06:16 PM

Oh and I just realized that on my initial post I have a typo! My car is a 1990 535i, not 1993....silly me. Doesn't make a difference with your sage advice, does it?

jeaux 12-12-2012 06:17 PM

Quote:

Originally Posted by snowsled7 (Post 7246378)
Cold fluid pumping losses requiring more time to build the pressure needed to engage the gearset.

This is very interesting. :thumbup:

robertobaggio20 12-12-2012 07:33 PM

Quote:

Originally Posted by snowsled7 (Post 7246378)
Cold fluid pumping losses requiring more time to build the pressure needed to engage the gearset.

So are you speculating that the oil pump in the tranny is busted ? If thats the case then all gear shifts should be affected not just reverse.

OP (original poster), please begin making enquiries for a rebuilt valve body or tranny, and a good used tranny, plus labour and time required. Call a few places and get a baseline. Also check the pricing for a full valve body overhaul with one solenoid changed, or just a valve body removal, general cleanup and reinstallation with one or two solenoids changed. I will try to get you some info in parallel need to check that out for my tranny too.

jeaux 12-12-2012 10:03 PM

Ok Roberto...sounds like a very expensive path lays ahead of me...but I will start checking. I am so hoping that deleting error codes and making sure I have the proper trans fluid level will miraculously solve the issue...you never know....
But I do look forward to your parallel research.
thanks,
joanne

robertobaggio20 12-12-2012 11:00 PM

Dont worry Jo. Lets take it one step at a time.

Steve sir if you can spare a few minutes, would you mind detailing how the reverse gear in your former e34 went out, the leadup to it, and any advice you received from techs about that which you feel is correct. Perhaps it can help us understand this a bit better.

BMWFatherFigure 12-12-2012 11:57 PM

If the tranny slip light has not come on it is not a band or broken component problem. I think you will find it will be a selector / valve body/ solenoid / 'o' ring issue. You need a tranny specialist rather than a BMW specialist. Most stealers don't seem to be either one of those.....


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