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01 740iL Transmission problem

113K views 96 replies 52 participants last post by  arpad3 
#1 ·
I just bought a 2001 740IL that I love, but it seems to have a transmissin issue. The car has high mileage but a very good service history. It has been serviced by a BMW specialist. At about 40 - 50 mph, in drive, it feels like the tourque converter is trying to lock up and then releases constantly. There is a scraping type noise at the same time coming fron the transmission. If I drive the car in the manual shift mode it does not do this. It seems like it has a bad sensor or the tourque converter might be on its way out. Has anyone else had this same problem? If so , what was the end result? Thanks Bruce
 
#27 ·
Hello everyone. Please read my previous posting and if you have the same issue with your 740iL, I was able to find the problem. It took almost 2 months - the BMW dealers I visited could not figure out what was wrong, as the code did NOT show up (and you know how it is - no code "no problem"). I finally saw a Russian mechanic - during his immigration journey, he worked as a mechanic in Germany and now owns his service center for the past 30 years in US. When he saw my car, he said:

"Don wory - I fix". He said that the scraping noise was 100% NOT transmission, took the computer, connected to the socket under the navigation and started driving my car with the computer in his hand. 10 minutes later he came back smiling "I tell you I fix it - it's yur ABS pompa, when I drive, it's give me code". Who would have thought that a Russian mechanic, who barely speaks English, would have more knowledge and experience that 3 or 4 BMW certified delerships. After he looked up the code, it turned out that the ABS pompa is actually called DSC Compressor (Dynamic Stability Control Compressor) and the part number (for 2001 740iL) is 34516781435. The BMW dealer wanted $854.29 for this part new, I was able to find it used on the ebay for $107 + shipping. Problem SOLVED.

The other funny thing is that I never changed transmission oil and at 160,000 miles asked this Russian mechanic if it is true that you should not change oil, because, as many of you know, the BMW in USA tells you that you do not need to change it. The Russian mechanic (Alex) told me that the BMW person who tell me that, needs to be sent to Siberia. In Europe, the transmission fluid is changed on BMW cars every 30,000 miles, Alex said and "in Amerika zey wont to change transmishan for 5000 dolars, not yur oil for $250". What an experience. So, the moral of the story - if you have the same issue as I described, it is most likely the DSC compressor, and if you never changed your trans fluid - go ahead and do that and replace the filter too. Oh, by the way, do not listed to those who say that your car will not drive after you change it - anothe bunch of garbage ...

Hope I was able to help someone out there.
 
#30 ·
Troubleshoot DSC pump?

I've been plagued by this problem off and on for some time and no one can accurately troubleshoot this to definitively say what the problem is. It's really the only problem the car has but it's kind of a big one.

I was thinking maybe if I turn off the DSC from the dash button would this take the pump out of the loop? My thought is that if the problem disappears, voila that's what we need to look at.

In my case you can be driving along generally fairly low speed 25-35 mph. may or may not feel a slight shudder. Then instant limp mode. Pull over, remove key. wait 20 seconds and then fine again for a while.
 
#36 ·
need help!
I recentlychased a 1997 740il, ran great for the first three weeks then the car wouldnt start! took it to mechanic had diagnostic done and was told the neutral safety switch needed replacing. Replaced it with a used one and the car started and ran great!
Now the car is doing the same thing again except, that the battery light is on, as well as the car not starting and i replaced with another switch , but that hasnt helped? I hooked two wires to the starter so that i can bump it without crawling underneath, which works great! the car starts like that and runs, but only in fourth gear. there are no lights showing on the drive area of the dash(eg: 1st, 2nd...D..) i have ordered a brand new switch but have concerns as to other issues that could be causing this problem. Any help would be greatly appreciated!
I love this car (first beeamer) really want to fix this problem asap.
 
#38 · (Edited)
transmission issue

okay so my 98 740i was slipping in and out of gear, like what most of you have described. so i pulled the tranny out and disassembled it to find that one of the clutch plate baskets had begun to break off and fall in between the clutch plates cause the transmission to slip. so we ordered the parts and seals we needed all for about $1200 dollars. but note that my transmission was going into failsafe mode where the transmission is locked into 3rd gear that was cause by the slipping because of the weakly built clutch baskets. if any of you have questions email me at 12dorr@gmail.com

another note my grandfather owns a body show that works on bimmers so i had access to all of the specialty tools that BMW uses on their cars, so it may be harder for others to fix this issue them selves like i did
 
#39 ·
Problem with my transmission on my 1998 BMW 740i

Hi this is only my third post. I purchased my 740 August 2011 with 120,000 miles on it for $3200. The car had been driving fine until recently when I go between 35 and 40 miles a hour the car hesitates then drives fine. It only hesitates between 35 and 40 then drives fine. Any suggestions on what to do. Thanks for any suggestions. Walter, Conover, N.C.. Buy the way what is a better car the 740 or 528.:)
 
#43 ·
I have a 2000 740 IL with 167k miles. After the water pump was replaced, it now makes lots of noise. In addition, I keep getting a Transmission Failsafe. However, the car still runs. After reading the posts, I plan to DIY the transmission. Can you recommend what type of ATF oil and filter and where to buy it. I normally buy from RoackAuto or Advance Auto parts.
 
#44 ·
Bump since I am having some kind of problem similar to this...sounds like the shaking/shudder/slipping is coming from the rear of the car. Any more info on that? I plan on doing a diff fluid change real soon so I'll check mine driveshaft out for anything abnormal.

Mathpro - what was the shops name that you went to? I'm in the loop so I went to RN Bavarian Motors once for diagnostics for speed sensors...
 
#45 · (Edited)
@gonzo40 and gsoman
Change the filter and fluid in your transmission. Your problem is caused by low fluid pressure resulting in poor torque converter lock up (shudder). Get the OEM filtran filter, 6 quarts of transmission fluid, Lucas trans fix, transmission pan gasket, and filter o ring. The fluid change steps can be found on this forum and can be performed in under two hours. A lot of guys on this forum use Redline D4, Mobil 1 ATF, or Maxlife. I've had great results with Maxlife (red bottle).
 
#51 ·
well 3 years ago I bought my 01 740i sport and had trans problems (trans fail message/no reverse) and had the small time dealer fix the problem. this was at 138k miles. I am now near 165k miles 3 years later and the car today just has no juice/power in reverse. :tsk:

I think I will stop by my indy shop and have them work on this. I am about at the end here on repairs on this car. about 9k in 3 years. I only paid $5k for it but still...
 
#49 ·
From my limited diagnostics I was able to do on my 99 740il I determined the problem I have (same symptoms as Bruce R) is faulty Vanos Adjuster Units. My car has what feels like a perfectly timed misfire/shudder most noticable around 40 or 45 when the transmission is in overdrive and torque converter locked up. The harder you accelerate the harder it pounds and makes that grinding noise. I had noticed on my road trips to seattle for parts that if I shift into sport mode the shudder is gone. Though the shudder is there at higher speeds it seems to be less harsh the closer the rpms are to 2k.

My explaination is as follows. I have had a P01519, and P01522 cam adjuster codes since i bought the car. Reset them and they are back as soon as i start the car up. I diagnosed this as a vanos issue based on some of the characteristics of how the engine runs. It seems to be a little sluggish at low rpms and kicks you back in your seat above 3k. The shudder is gone over 2k which is getting closer to where the vanos system is backing off. At low rpms vanos is fully active and thus the worn out components are slipping the timing and having to be readjusted over and over. I have replaced both vanos solenoids with no change.

My old auto instructor clued me into the "logic" built into these luxury car transmissions. In the case of a large misfire or loss of engine power the transmission computer slips the torque converter clutch to keep the car from jolting. If you pay attention to the rpms you can see when the clutch releases and then locks back up. Some times going up a steep hill with the low rpms i will get a prolonged shudder where the torque converter clutch doesnt reengage because the engine is running too rough.

Now as with everyone else, I am human and I could be wrong but id be willing to wager that im right. I am a newbie to BMW and there was a sharp learning curve but I think im starting to understand some of it now. The internal camshaft adjuster unit on the m62tu is something like 600 dollars apeice so for 750 i bought myself a new engine (102k miles.) My engine has 229k miles and is ready to retire. I have the new engine on an engine stand and am waiting on some new gaskets and seals for it. As soon as I tackle the job and swap out the engine I will be back to post my results. In any case now I got 4 spare vanos solenoids. :p
 
#50 ·
This is my first post and after reading everything on this forum I am still wondering what to do next, My problem with my 740il 2001 with 143k miles is when stopping, slowing down then accelerating it fills like the transmission slips out of gear, rpms go up on engine then suddenly it catches the gear abruptly. One mechanic says fluid is ok and another mechanic says the transmission needs rebuilt.
Please give me some suggestions what to do next, Thanks.
 
#52 ·
here is a flaw in the valve body's reverse check ball. The problem manifests first as a hesitation in engaging reverse. Then, a hesitation in first. Lastly, complete failure by trying to engage the first and reverse gears at the same time. The problem is the check ball for the reverse system is plastic, and wears down over a long period of time. It seems to happen around 150k miles. The only way to fix it is to replace the check ball with another. ZF makes a refit kit
 
#53 ·
Quite an interesting thread, this one, so I shall add my penny-worth.
Wife's E38 750. I had a "noise", scraping type, when I pulled out of an entrance uphill to the right. Nowhere else. Over a few weeks it got worse. I couldn't find anything.
Finally I took it to a very good "indy". He put it on the ramp, and immediatly a mechanic diagnosed a torque-converter problem. It made sense.
He dropped the transmission, and sent the converter off for repair/recon.
Specialist confirmed that the "lockup" clutch inside the converter had failed.
Replaced it all. Started up and the noise was still there! We were all a bit perplexed, and redfaced. I took the car home and put it on it's naughty step (wheel ramps to some), to look at an oil leak.
Whilst underneath I noticed that the fan shroud wasn't properly in it's locating lugs. Took it out and fitted it properly. I noticed marks on the fan blades, and on the shroud. Whoops! Funnily enough, the noise disappeared. I was rather glad the converter had needed the recon anyway!
Mike.
 
#55 ·
Suggests to me that your engine mounts may also be suspect - with a broken RH mount the 'uphill to the right' motion would cause the engine to lean over to the left, thus allowing the fan to come into contact with the shroud - if it was just that the shroud was able to move enough to contact the fan, I would have thought it would do it all the time?
 
#56 ·
The engine mounts are fine. Unfortunately the car was owned by a plonker before I got it. The shroud was not located in any of the slots, and instead of two plastic rivets at the top it was "secured" with two nylon ties! just putting it in properly fixed it. I have found loads of similar issues. The heater core was blocked and an attempt to remove it had been made. most of the console fixings etc. were broken. It's nearly sorted now. Rubber gearbox coupling to change, and "Throttle" error to sort.
Lucky fellow living in Adelaide
Mike
 
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