The above vehicle was being driven by a friend's son when it simultaneously 
1) let out a plume of white smoke from under the car (not the tailpipe)
2) left a long line of fluid on the roadway as it coasted to the shoulder
3) Slipped out of gear into neutral.

Towed car home.

Will not shift into any forward or reverse gear.

Finally got it up on all 4's to learn/confirm:

1) Orig BMW tranny fluid is indeed honey colored, ending my search for traces of red ATF under the car (remember, 1st BMW I've been under, so the joke's on me)
2) There was a slick of tranny fluid on the underside of the vehicle that stretched 3/4 the distance from the tranny to the rear end.

I think the white smoke was the tranny fluid burning when it hit the cat cons
3) I found the inspection hole for the flywheel (which seems irrelevant, but it felt very gooey in there and below.

Supposedly, there was no indication of tranny overheating at the time.

I'm wondering if a seal on the torque converter or pump let loose, allowing the fluid to spray forward from the pressure, then down and out the car bottom.  Once there, the wind blew it towards the back of the car, burning a bunch on the catcons and leaving a mess
I am yet to pull the drain plug on the pan to see what's left in there but I'm not hopeful.

If it is dry is it a goner?
 

Also, is there ANY way to visually inspect the torque converter/transmission interface without separating the trans from the engine?

I figure the least we could do is drain it. If anything significant comes out, then maybe drop the pan and clean the filter, throw in some proper tranny fluid and 
A) see if it leaks out the front
B) see if the car goes into gear when full of fluid

Also, where is the fill plug on this tranny and is it a hex or a torx? Better yet can someone post me a link to a site with good exploded drawings so I don't have to ask these kinds of mundane questions?
Thanks

Derf

Hi Fred

I'm guessing as you say the fluid is honey coloured that the fault may be with the transmission cooler (which may be part of the engine coolant radiator or a completely separate cooler). If this has burst, then that could be the reason for the loss of fluid and also mixing with coolant (if part of the radiator) resulting in the colour of contaminated fluid - emulsification).

I would check the source of the leak before committing to replacing any parts...probably thoroughly wash underneath with a jet wash and brake cleaner and then fill with cheap fluid and run to see where it is coming from.

Let us know how you get on with it

Cheers   Trevor

Thank you Trevor.

I'll get it cleaned up and check the coolant for contamination/presence of a separate transmission fluid cooler.  Obviously the cooler lines connect to the transmission -- but where? Left or right side or one on each (as sitting in the driver's seat)? I don't have much maneuvering room under there and I can't see much with those undercarriage cover plates in the front.  Was hoping to avoid removing all those but I suppose I will not be that lucky.as a complete cleanup will require removal of at least the one in front of the tranny and the one under the oil pan (has a nice oil leak to boot..

What color should the coolant be for a 2003 BMW 325i (not contaminated)?  The residue under the car seemed pretty clear, but as you indicated, it may have a separate transmission fluid cooler.  I am familiar with the headgasket oil/coolant milkshake but have never actually seen firsthand a coolant+transmission fluid emulsion.

This project is going at the owner's pace so my lack of an immediate answer should not be interpreted as a "one n done" question.

I'm actually a moderator for a Saturn forum here in the US and I do NOT do that when joining other forums.  After 11 years it still bothers me.

I WILL be back

Thanks again 

Derf

Not entirely sure where the lines are but if the ATF has contaminated with coolant then chances are the cooler is part of the radiator (check for coolant level/loss).

If so, then another radiator is required. If it is seperate, then the coolant hoses will be going to it (somewhere near the front lower part of the radiator. 

 

Hi Derf

Doesn't sound like good news I am afraid, I would say definitely a blown seal that has dumped the fluid so looks like a box out job to get at what you need to fix. At least your in the US where an Auto isn't viewed as a box of magic bits and if its opened they escape never to be seen again and priced accordingly.

Take a look at www.realoem.com put in the last 7 digits of your vin and then look at the Auto Transmission file it will at least give you some idea of what your looking for with the exploded drawings. It's a really useful source for part numbers etc for any model.

I am not sure but I think the Z denotes ZF transmission so any competent Transmission specialist should be able to help

Good Luck finding a fix

Dave

Well, I'm back.

 

Tranny fluid found leaking from the front out of he flywheel inspection hole. No signs of transmission fluid cooler lines or the cooler leaking or damaged.

Coolant in radiator surprisingly clear -- may have been changed along he way. No signs of cross contamination with transmission fluid.

Transmission drained.  Maybe 1 quart left.  Didn't bother measuring. Not good.   Decided at this point to NOT drop the pan, as the owner and I did not see he point of throwing money at it for a filter, gasket, and new pan bots.  Not until we had SOME indication this transmission actually wanted to and could go back into gear.  Even a hint.

This was the NASTIEST used transmission fluid I have ever seen in my life.  Deep dark cloudy thick black//brown fluid.  Had to be the original fluid. 

IMHO, BMW was obviously "setting up" their customers for 1 transmission replacement during the life of the vehicle.  To have a transmission (auto) last much above 150k mi with regular transmission service is pretty good.  But if the fluid is any indication, this transmission is on borrowed time after 100K if the lifetime fill is left undisturbed.

In an attempt to get some of this disgusting fluid out and replace it with something functional (Valvoline Max life , met spec for the 325Z transmission  -- right on the label.)  Did two drain and fills, shifting gears after each one to circulate fluid -- but because the gears were not engaging, I suspect this was not actually occurring.

When I did the second drain, it looked pretty much like the first -- maybe a lighter dark brown,  It was at this point that I realized the red fluid we were trying to drain n fill was not really mixing with the existing nasty fluid.  Additionally, the liquid was coming out of the fill hole as pure clear red, another indication that there was no real mixing occurring.

The pump inside the transmission was making awful groaning sounds like a dry pump does.  We shut it down.

Semi-conclusion:  Pump failure and possibly other seal failure, allowing transmission fluid to leak out the front of the transmission.  Seal disintegration may have scattered debris throughout the whole system. Pan drop would verify that, but irrelevant right now.  

Swapping in a used transmission is probably not as costly as diagnosing this one and then rebuilding.  The problem is, you don't know what you are getting in a used transmission--is it as abused from neglect as the one that just failed?

I am trying to convince the owners to sell it as a running engine/nice interior dent free exterior with decent paint---
--  + income from failure vs unknown transplant cost 
--  unknown reliability of the used tranny--unless it has been fully rebuilt already.

Don't know how much a good engine/blown tranny goes for in USD .  Any guestimates?  

Thanks to all for your guidance on this.  I received a total of ZERO responses or suggestions on two US based BMW forums

The typical US BMW owner does not have nor want knowledge of how the car works.  They just want it to run.  Until it fails.  Then take it to the Stealership to overpay for repairs.

The owner of this BMW is DIYer and happily bucks the trend.  But it will all be for naught.

Thanks again.
Derf

Hi Derf

I find it incredible that a Premium manufacturer actually states that the Transmission is sealed for life ??? BMW seem to think the "life" of a vehicle ends with their warranty liability. If you check ZF's web site you will see they recommend changes at 60 to 80000 kilometers, I service mine to ZF guide lines.

Sounds like seal failure and debris has blocked the pump so a box out job to rebuild I am afraid.