Odd noise between 58 - 60 mph in 5th gear

[parkerbot]

I noticed a constant medium pitch humming noise (if you've ever been in a truck with large tires, the road noise from them is very similar) when I was driving around the other day with the windows up that occurs between 58-62 MPH with the loudest at 60 mph. The noise as far as I can tell is speed dependent and doesn't change with turning and appears to be coming more from the front then back of the car. Happens in manu-auto mode in 5th gear and in D.

I've also noticed at around the same constant speed (not accelerating) I'll get a slight jerk with a ~300 rpm increase, and found an error in INPA for excessive torque converter slip.

I'm inclined to believe all of these issues are related to possible failing/failed torque converter, but I have about 0 experience with transmissions so I'm turning to you guys to possibly point me in the right direction. I plan on doing a transmission fluid/filter/gasket change this weekend as the car has 109k miles on it and I'm almost certain the PO did not change it prior to my purchasing it. Thanks in advance guys/gals.

2003 330I 109,500 miles
Last 7 of vin: KM30280

[parkerbot]

Bump/jerk happens right around 60 mph @ ~2100rpms and jumps up to ~2300rpms. Occurs once and doesn't happen again until after I've come to a stop and accelerated back to ~60mph. Again these are the symptoms and I'm not sure if they are related but seeing as they all occur at roughly the same speed I'm inclined to believe they are. I'm still due for a transmission fluid change. Had the wrong gasket/filter set for my ZF trans so had to wait for it to come in this weekend. Hopefully it does the trick but we'll see I guess.

Any help on narrowing down the issue(s) would be greatly appreciated.

[dworthy]

Have you cleared to code to see if it comes back? Did you also check in the DME as well?

When was the last time the fluid/filter was replaced? May not have much to do with the slippage other than old fluid just doesn't work very well.

[parkerbot]

Code has been cleared a few times, but comes back. DME only has intermittent lean codes from a PITA vacuum leak. Smoke test is on the to do list but low on the priority list atm.

I'm almost 100% certain the fluid and filter have never been changed. The PO either had no clue what they were doing or had a crappy mechanic as evident by all the rtv used instead of $2 - $4 O-rings and factory plugs still in the car at year 13 @ 100,000 miles. The electrode had receded and burnt channels through the insulator. Was really impressed with the plugs though. Had no indication they were in the shape they were in. Just wanted to pull them and check condition since I'd just bought the car.

Question....is there a less expensive route for the 22 aluminum M6x22 torx bolts for the ZF trans pan than ~$4 apiece? $98 for a set of bolts seems a bit excessive

Edit:
Also I shifted to neutral when experiencing the noise and did not notice a difference in pitch/volume until I coasted below 58mph. If the noise was TC related should it have disappeared? Thinking maybe something else going on in addition to the TC slippage.

[dworthy]

100 bucks would be about right for the filter, gasket, and bolts. Where are you getting your parts from? Here is one of the forum sponsor: https://thebmwminipartstore.com/part...&siteid=218365

I do believe that in YM-03 they made a change for the transmission, so it would be important for you to plug your VIN in realoem.com to ensure you get the correct one. The link I provided is a later YM-03 kit.

I am not a automatic expert, but on some of the older (E-38) transmission they have slippage codes, and shogun (moderator) have given advice on adding a torque magic fluid or something to that nature. Here in Europe, a BMW with an auto transmission in a 3-Series is rare, say around 15% unlike the U.S.

[parkerbot]

I got the filter/gasket, fill, and drain plugs from fcpeuro and ecs tuning for just under 50...the bolts by themselves cost almost $100. This seems a bit excessive since similar m6x22 aluminum bolts at a hardware store are closer to $0.40 apiece vice ~$4. Might just go that route anyway if I can find the right length...if not just buy long and dremel the excess. Not like I need milspec bolts to hold together a chaff launcher...just a pan that has barely hand tight torque on it. Maybe I'm wrong and there is something truly special about the bolts that justifies the high price (other than being for a one off BMW transmission). If so please correct me.

[bmwdirtracer]

Sorry, parker, I'd missed your thread. Bolts are bolts. I do not believe these are aluminum, They just have a Torx head. Most kits come with the bolts, for this trans, but hell, just reuse the things. They're just normal bolts, their worst issue is that the torx hole strips.

I wonder whether you're reading transmission codes? Seems to me you have an issue with the convertor lock-up. It might be worth having the EGS reflashed with newer software. Clear all adaptations. Any codes in the DME?

[parkerbot]

Egs is showing Torque Converter Clutch - too much slip
Abs module showing can timeout and engine torque not adjustable
Dme showing lean codes for banks 1+2 and an error "control unit self-test 3"

EDIT: Those were pulled with bmw scanner 1.4. Below is the error pulled with INPA from EGS. Can't access all modules on INPA yet...think I need to bridge pins 7 and 8 on it. Live data was showing wire L3 and solenoid 3 off/disconnected (vehicle not moving in P).

E R R O R M E M O R Y R E P O R T
-------------------------------------
Date: 05/25/17 19:45:55
ECU: GS8604
JobStatus: OKAY
Variant: GS8604
-------------------------------------------------------------
RESULT: 1 errors in error memory !
-------------------------------------------------------------
48 Torque Converter Clutch - too much slip
Error frequency : 10
Logistic counter: 59
Error occured 1. times at:
Mileage/Km-reading 175870.00 km
Gear: Implausible 0.00 0-n
Gearbox Oil Temperature 95.00 degrees C
TCC closed 2.00 0-n
Error occured 2. times at:
Mileage/Km-reading 176000.00 km
Gear: Implausible 0.00 0-n
Gearbox Oil Temperature 92.00 degrees C
TCC closed 2.00 0-n
Error occured 3. times at:
Mileage/Km-reading 176910.00 km
Gear: Implausible 0.00 0-n
Gearbox Oil Temperature 90.00 degrees C
TCC closed 2.00 0-n
Plausibility
Error activates Fault-Lamp (MIL)
Sporadic error
Error present
================================================== ===========

[bmwdirtracer]

Damn, that's quite a troika. Each issue greatly complicates diagnosis of the others.

I'd personally start with the DME codes, because the DME needs to supply valid torque/airflow measurements to the EGS and DSC, or the other computers become lost.

That said, it would seem like the torque convertor is likely failing, but I'd do the fluid/filter swap, and make the DME happy before throwing the convertor at it, because that's so much work.

CAN timeout is not good, but again, deal with the problems you can see, before attacking those which are possibly symptoms, rather than culprits.

[dworthy]

Yes, get 7&8 done, so you can get to all the modules.

Start with the DME codes first, as that will affect the EGS and set a MIL.

Can you post the DME codes as well?

[parkerbot]

Sure thing. I'll post em when I get home. Was going to post last night but apparently I saved only the two active lambda codes and not the shadow codes which is where the system self test 3 code was sitting. Do remember it saying something about can temp @ 50 degrees celcius...anywho I'll pull again tonight and make sure I save the right ones.