e38 740i Guru's??

[wildeian]

The old man recently bought the 4.4i auto monster above, and has started having probs with the transmission.

After driving off the ABS, DSC and brake warning (!) lights come on. If he stops and switches off and back on again, sometimes they go out.

Shortly after this, the car goes into 'limp home' mode, and the old man has chavs on scooters over-taking him!!

Dealer couldn't help unless buckets of cash were thrown their way!

Gonna change the transmission oil and filter, but any suggestions most gratefully received.

Cheers, Ian

[Ant]

gotta be ABS sensor or gearbox speed related

the ECU is seeing slippage over and above what is expected and will protect the trans with the failsafe mode

needs a proper diagnostic, by someone who understands the systems, and how they all relate to each other.

I had this on a customers car in the summer, they spent £2K @ the stealer with no joy( or refund ! ) the fault was the TPS had failed on the traction control TB and was causing the issue

Dignostic dude, its the only way forward ! whats the miles BTW ?

[Andyboy]

4.4 litre M62 Steptronic wrongness!!

[wildeian]

Not sure on the miles Ant, I can find out.

Gonna try transmission oil and filter change, as that has worked for some people.

The old man has taken it to a guy with a portable diagnostic machine, and to the dealers with no real answers (although the dealer tried to charge £62 + labour for a new seatbelt, because it had turned the other way in the buckle!! )

Is this within your area of expertise, as he lives up the road from you in Chatham?

Cheers, Ian

[wildeian]

Mileage is 127k

[Ant]

Hmm pass my number on, I'll gladly take it on and give it a once over

G/box oil change is always required on these post 100k, lifetime oil my backside

[wildeian]

Cheers Ant!

[wildeian]

Any tips on how to change gearbox oil and filter greatly received!!

I take it the filter is inside the gearbox, and I need to drop the sump??

And what oil does it take!!?? (lifetime??)

[Ant]

yep, sump off dude, be careful !!

filler hole should be marked, if you have TIS you can find the full procedure there

lifetime oil is £Â£Ã‚£Ã‚£Ã‚£ form the stealer, TBH I can see no spec change over normal ATF Dextron 3 apart from the colour.

I always put the correct stuff back in though, the risk is too high, a new box is Mega £Â£Ã‚£

[wildeian]

Cheers again Ant!

[wildeian]

Jesus!!! Lifetime oil is nearly £20 a litre!!

[miniblob]

Let us know if you find the problem - have a similar sounding issue with my 850CSi at times - although i suspect my prob may be a bit more complicated!!

[wildeian]

Quick update:

Went down to the old mans to change the g'box oil and filter, but on the way he phoned and told me about something he read on the TIS he just got. It all pointed to the loom inside the drivers front wheel arch, saying sometimes if it got wet or dirt in it it could affect ABS, DSC, traction control and windscreen washers.

So instead of the service we checked this out. The loom was indeed saturated with water and dirt, and after a good clean, dry and tape up..........the fault was still there!!!

Although now the fault is a bit clearer in my head:

Car starts up fine, all lights go out. If the car is in gear and the handbrake is released, the car as normal will creep forward. Everything at this point still seems normal, until the throttle is pressed and bingo - DSC, ABS and brake warning light (!) come on.

I'm thinking next, while I have the sump off the gearbox to do do the service, I'll change the speed sensors (No. 6 in pic), as as Ant says it seems to be speed related.



I checked the end of the ABS sensor that was near the drivers side front wheel, but didn't have time to follow it to the other end. Can anyone tell me where it ends up??

Not working on it again till next week so all advice greatly received. It gives me something to think about while I change the engine in my Touring!!

Cheers, Ian

[Ant]

Dude, time for another diagnostic on this beasty

you can spend £Â£Ã‚£Ã‚£Ã‚£ on this and still not cure the issue.

[Dan318-is]

My god that diagram makes e30s look like lego blocks! how complicated can you get?

[Andyboy]

Any tips on how to change gearbox oil and filter greatly received!!

I take it the filter is inside the gearbox, and I need to drop the sump??

And what oil does it take!!?? (lifetime??)

Pretty easy if you have a ramp! Only ever use a BMW/ZF filter as the cheap ones from Euros/GSF can collapse. Drain the oil out of the 'box, refit the plug and fire it up for 4-5 secs. This empties a lot of the oil from the torque converter. Drain it again and remove the sump. With the old 310Z boxes (24v E36 and E34) which used ordinary AFT at 10p a gallon you'd run the engine with the drain plug out whilst pumping fresh ATF in to do a complete change - but the Esso oil in the V8's is too pricey for that. Don't be tempted to use Dextron 111 - too many Yanks have tried this and fried the 'box after 100 miles! Dextron 111 is probably good enough but it doesn't mix at all well with the synthetic Esso 'liquid gold'.

Change the filter (and the rubber sump gasket), wash the sump out and refit it. Fill with oil through the refill plug until it starts to run out. Refit the plug and fire the engine up. With it running and it P or N, remove the plug again and top up with oil until it starts to run out.

Now, the BMW/ZF procedure is to get the 'box up to temperature which is between 30 and 55 degrees C (86-131 Fahrenheit) - that means draining some oil into an aerosol can lid and measuring it with a thermometer. To be honest just leaving it to idle in P or N for 15 mins doesa the job. On the ramp, let in run in D and R to make sure all the oilways are full. After 15 mins remove the refill plug and top up with oil, job done.

[Andyboy]

By the way - you need to talk to a company called Automatic Transmissions in Hornchurch - very good guys with the fault code readers and loads of spare parts.

[wildeian]

Cheers Andyboy

Ant, looks like I'll be getting the old man to give you a bell then!!

[wildeian]

Changed the DSC unit on the front of the ABS pump, and it appears to have solved the problem

DSC light is staying on at the moment though, but no ABS/fail-safe problems...