E90 320i oil leak - with a twist!

[vimal32]

Hi,

Need some help please, if anyone can point me in the right direction.


E90 320i,
2008 pre facelift with N46T engine ,
Automatic,
130 000km


I've been noticing some oil (or at least I think it is oil) on the garage floor from last weekend.
Not a lot, maybe the equivalent of 3 to 4 drops per day.
seems to be coming from towards the back of the engine and towards the drivers side.

The twist is that the oil is clean, as if its brand new oil.
The car hasn't been serviced lately (last done end of last year), so the engine oil should be fairly black.

Lifted the car and removed the covers under the engine and gearbox,
covers are bone dry, not a drop of oil on it.

I go under the car to look and cant see anything, everything looks absolutely dry,
checked around the sump nut, sump, gearbox sump, vacuum pump, power steering fluid reservoir, etc, NOTHING!

Oil level, still looks fine and not dropping any faster than normal usage,
Brake fluid level is fine,
power steering fluid level is fine.

I suspected gearbox oil initially because of the location of the oil droplets, but surely that oil will be dirty as well after 130 000km?
Maybe its brake fluid, because that's the only thing that would be clean - but the location of the drops doesn't point to brake fluid, i could be wrong...

Prefer DIY, but probably need to take it to a professional to have a look if i don't find anything soon.

Anyone with any ideas?

 

[Sheldon13]

Hi

There should be a tray above the exhaust manifold.
Check if there is any oil collecting on that.

 

[vimal32]

Hi

There should be a tray above the exhaust manifold.
Check if there is any oil collecting on that.

Hi,

I checked that and around the valve cover gasket too, dry.

 

[Solo Man]

Could be aircon water. Find out where the aircon drain pipe is and see if it isn't blocked which would account for the "drops". Take some compressed air and blow into the drain pipe to clear it. I had this problem on an Opel Corsa where the carpets inside were wet and water would run onto your legs when going round a corner. Googled it and found that the drain pipe clogging up is a common problem. Got under the car and opened the drain pipe which was clogged solid with mud/dirt. Nearly a cup of water ran down on my arms upon opening up the drain pipe. The other place where it could leak out is from the gearbox megatronics plug. Also a well known problem on certain BMw's. On my E53 X5 2005 model diesel it would only start leaking after standing for three days without driving it. My theory is the torque converter which is filled with oil when the car is running, drains back into the gearbox and overflows at the seal on the megatronics sleeve. Bought a new sleeve from BMW and had it fitted (had to drain gearbox oil again to fit it as there is no other way to get to it) and the leak is gone. Hope this helps! Btw, the oil leaking from the sleeve is quite difficult to see as it is above a plastic "pan" that is fitted below the gearbox.

 

[vimal32]

Could be aircon water. Find out where the aircon drain pipe is and see if it isn't blocked which would account for the "drops". Take some compressed air and blow into the drain pipe to clear it. I had this problem on an Opel Corsa where the carpets inside were wet and water would run onto your legs when going round a corner. Googled it and found that the drain pipe clogging up is a common problem. Got under the car and opened the drain pipe which was clogged solid with mud/dirt. Nearly a cup of water ran down on my arms upon opening up the drain pipe. The other place where it could leak out is from the gearbox megatronics plug. Also a well known problem on certain BMw's. On my E53 X5 2005 model diesel it would only start leaking after standing for three days without driving it. My theory is the torque converter which is filled with oil when the car is running, drains back into the gearbox and overflows at the seal on the megatronics sleeve. Bought a new sleeve from BMW and had it fitted (had to drain gearbox oil again to fit it as there is no other way to get to it) and the leak is gone. Hope this helps! Btw, the oil leaking from the sleeve is quite difficult to see as it is above a plastic "pan" that is fitted below the gearbox.

Hi,
Thanks for the suggestions,

It is definitely not aircon water, It feels oily and looks slightly yellow in colour, consistent with new oil or brake fluid.

I will look into the megatronics plug, first time I've heard of this. Will go under the car again to have a look.

Come to think of it, I'm also seeing the drops after a day or 2.

was your repair expensive?
How much for parts and labour?
Is it a possible DIY job?

 

[vimal32]

Here is a link to what I think Solo Man is referring to and could be the solution:
Did anyone else have this problem on a E90?

http://blog.bavauto.com/15022/bmw-a...id-leak-mechatronic-sleeve-ga6hp19z-ga6hp26z/

 

[Solo Man]

vimal32 is correct. In my case i had the oil and filter changed but did not realize the gearbox had a leak as i had cleaned it when i got the car and having driven it nearly daily it did not show a leak when they serviced the gearbox. I had quite a shock when i took the car out after it had been standing for a week. There was quite a big puddle of oil on the garage floor. Cleaned the gearbox and noticed that it was coming from the megatronics plug. Took the plug itself out and cleaned it with engine cleaner and then drove the car but it stayed dry and clean. Left it again for a few days to check and after three days it had overnight left a big puddle again (i had a big cardboard under the car this time) Ordered a new sleeve and had the guys replace it for me. Think the sleeve was about R220. If you are in Gauteng take the car to Nico at ZF. He will do the service and replace the sleeve for you. I also had a problem with the car thumping you in the back when coming to a stop. The service centre reprogrammed the gearbox and it is 99% better now. AS the gearbox learns your driving style i tend to slow down at a stop/red robot and just before the car comes to a stand still i release the brake for a "soft" stop. This helped a lot after the service to cancel out the "thump".

 

[vimal32]

vimal32 is correct. In my case i had the oil and filter changed but did not realize the gearbox had a leak as i had cleaned it when i got the car and having driven it nearly daily it did not show a leak when they serviced the gearbox. I had quite a shock when i took the car out after it had been standing for a week. There was quite a big puddle of oil on the garage floor. Cleaned the gearbox and noticed that it was coming from the megatronics plug. Took the plug itself out and cleaned it with engine cleaner and then drove the car but it stayed dry and clean. Left it again for a few days to check and after three days it had overnight left a big puddle again (i had a big cardboard under the car this time) Ordered a new sleeve and had the guys replace it for me. Think the sleeve was about R220. If you are in Gauteng take the car to Nico at ZF. He will do the service and replace the sleeve for you. I also had a problem with the car thumping you in the back when coming to a stop. The service centre reprogrammed the gearbox and it is 99% better now. AS the gearbox learns your driving style i tend to slow down at a stop/red robot and just before the car comes to a stand still i release the brake for a "soft" stop. This helped a lot after the service to cancel out the "thump".

Thanks @ Solo Man,

I will make arrangements to get it to Nico asap. I have read many good stories on the forum about Nico and ZF.
I'm glad the sleeve is not an expensive part, was getting a bit worried.

thanks for your help and for the info. Will report back to the forum after I've been to ZF.