M30 gearbox oil leak - solved & back on the road!

[Theo]

Disaster struck today on the 335!

I had been suffering from an oil leak on the car, initially suspected it to be rear main seal failure, but after having it checked out by Ant he decided this was not the case. So I thought its more liekly than not just an accumulation of oil in the bellhousing, and sure enough the more I drove it the more minor the leak became.

However when I changed the gearbox oil after noticing it gettting a bit loud, virtually nothing came out, what did was horribly black (just like the engine oil was when i though it was this that was leaking). Anyway, I filled it up with nice new ATF - took it for a drive, looked under the car and it was dripping out nicely again, and was clearly the new ATF.

What makes this even more annoying is that it is on 9 days until I'm driving to Nurburgring

Any advice guys? I'm guessing its the front seal on the gearbox?

Help very much appreciated!

[dazleeds]

take a day off and change the seal is the only solution im guessing

[Theo]

Yup, suppose thats what I'm going to have to do, but the gearbox will be a swine to remove - some of the bolts on the bell housing are even harder to get to than on an 325. F**k.

[eko]

Theo,can you not get access to a ramp?
Thats going to save you loads of grief/time/knuckles etc!

[Theo]

Sadly not eko, i'm thinking it might even be easier to pull the engine and box out together.

[tomson]

Sadly not eko, i'm thinking it might even be easier to pull the engine and box out together.

would probably agree with that!

[Simon13]

and hope the clutch isn't fubared too badly either!

Theo why didn't you check all this before you fitted the engine!

[Theo]

Ahh Simon. Good old hindsight. I had no reason to believe that it was a problem, the seller made no mention of it - lesson learnt I suppose.

[Simon13]

Everyone is having a hardtime with their cars before the trip this time, the worst so far.

I'm not going to jinx it anymore than hoping we all get our cars in good working order before they go

[eko]

Theo,im sure someone on here local to you could spare a weekend to help

Good luck mate!

[DRIFTBOY]

Theo.
Oh dude, I'm feeling your pain!

I'm not sure how you go about changing the front gearbox seal to honest, never had to do it.

Have you got the part / parts to fix it ?

Martin.

[Theo]

Not got the parts yet, only discovered the problem this afternoon

I'm still quite puzzled as to why the oil is coming out as quickly as it is, not as if the gearbox oil is under pressure. The following is the exploded diagram - nice and confusing. Liking the look of no4 coming in at a cool $425

http://www.realoem.com/bmw/showparts.do ... g=23&fg=15

I'm guessing it's no. 6 that's the problem, but maybe it is even worse. Wouldn't suprise me

[ed325i]

the seller made no mention of it

It was not leaking when I had it
If it was it would have been leaking out when you picked it up.
Its got a new oil seal to, the only one I didnt change was the gearbox out put one.

[Theo]

It only leaks when the car is driving, or when it has just been driven.......

[Ant]

Theo, ATF is incorrect dude !

put some SAE80 in there and re-asses.

ATF for later post 92 'boxes mate, and really really noisy Getrag 260s...

As I said to Oz the other day.. the big man upstairs is telling you ALL, this trip is a bad idea

[Theo]

Doh. Thought that ATF was the shizzle for these boxes.

That nasty black stuff that was in the gearbox before made it's way out of there, i think that is what was leaking out rather than old engine oil. Worth a go anyway I suppose.

Dave, Oz and me are all having a 'mare leading up to this trip. If I was religious I would be worried!!!

[gareth]

shiiiiiiiit dude! that's one of my worst dreads with the M30 swap and the reason i splashed out on a new clutch while fitting!

just an idea, the oil breather (part 3) didn't get flattened / blocked or anything duting the squeeze into the car did it? that would possibly explain things...

[Theo]

Well I checked the breather on the gearbox hoping that it would be manky and blocked, it seems fine although it's a really inaccesible. It rotates freely and moves up an down a little, which I assume means it's ok?

Looking like an engine&box out jobby. To make things even more fun, the oil pressure light came on in my 325i last night - so backup car isn't looking promising for the 'ring either!!

[Simon13]

how do you mean?

[Theo]

Eh?

M30 turd - gearbox needs looking at.

Chrome turd - oil pressure issue.

[Simon13]

yes thats what i mean oil pressure problem

light on when driving? light flickering on idle when the engine is warm? light takes ages to go out on start up?

[Theo]

This only happened last night for the first time but, basically all was normal until about 5 miles of normal driving then the light would come on. I noticed that it would stay on when you had the coasting in neutral with the engine on, but if you then put it in gear and used a little throttle it would go out.

I recently replaced the pressure switch because it was leaking badly (with a used one from another engine of mine after bmw gave me the wrong one when I was in a rush for it) but this is the first time I've seen the light come on since having the car. Oil filter was changed over christmas, oil is also pretty fresh as a result of topping it up regularly when my old pressure switch was leaking.

Sorry for the essay!

[Simon13]

hmmm my alpina used to flicker on idle, this was low pressure but with in spec. on mine it's worn pump. Sounds like this could be your problem but don't quote me on it!

[Theo]

I really hope it's not the pump, as thats another bastard job to do.

[Simon13]

ditto!

to be sure get the oil pressure checked before you do anything. Mine was or is in spec even though the light flickers on idle.
if it is too low on idle when the oil is warm then you could raise the idle a touch from the throttle body, it's a bodge but it could buy you some time

[Theo]

Pressure is ok at idle, the light only came on after a few minutes of driving. It was however fine driving from London to Kent at a fair few knots only a couple of days earlier.

Will get a pressure guage on there and see whats happening - do you know what pressure should be and what the tolerances on this figure are?

[Jon_Bmw]

The oil pressure problem sounds worrying. As it doesn't sound like your typical broken wire or pressure switch fault as it only happens at warm idle. On my s4 the cold idle is 5 bar, warm idle 2 bar. Driving on warm engine any load and it shoots up to 5 bar. Can you borrow Andrews new toy that he brought at coombe? But I am not sure if the s14 and m20 pressure switch and the same thread and pitch?

The light out at cold idle is also in keeping with something more serious than the pressure switch and wiring. Bollacks.

[Theo]

Uh-oh. Thanks for that good snippet of news Jon! haha.

The car still sounds fine and runs really smoothly, so hopefully no major damage done just yet. Can't get hold of Demlots guage - Cambridge is a long way away, especially without a functional car.

Can't decide which car to try and sort out....

[Theo]

I woke up today feeling quite active so I decided to take the engine and gearbox out and do something about the leak. Pictures below show the problem, the cover with the six bolt holes was put on wrongley meaning there was a hole which gladly pissed out all the oil whenever the car was running - pics below!




IS there a gasket which sits behind this cover, or is instant gasket ok? Below is the link for the diagram on realoem. Also interested to know if the clutch which has had atf thrown over it is buggered or not? Is it possible to only buy a clutch plate, or are they only sold as a kit?

http://www.realoem.com/bmw/showparts.do ... g=23&fg=15

[ed325i]

Sorry Theo that was me who put that on wrong
It must go at the top ?

[DRIFTBOY]

Crikey Theo, you don't mess about!
Good work dude!


Ed - We've all made errors like that, but it's very big of you to admit it on a public forum! Very honest.


Clutch friction plates can be bought seperately but you mind find it hard to get hold of just that and not a full kit, not sure what the price difference is so might as well to just put a new kit in there.

Did the clutch slip when you drove it ?
Is the plate visibly contaminated with oil ?

Also, how's your flywheel ?
If it's in a bad way (not related to oil, obviously!) I have a spare you can have. Mine isn't like new or anything though.

Good luck mate!

Martin.

[Theo]

The arrow should point downwards - you can see near the 225 stamp that there is a flat surface and this is where that hole which the screwdriver is pointing at should sit against.

Not to worry though, mistakes are easily made and it really wasn't too much hassle gettting the engine out - a mornings work.

[Theo]

Martin - i felt energetic this morning so just got stuck in!

There was some clutch slip before, but only when I was really giving it the beans I was thinking of soakin it in meths? Some oil was evident on the plate.

Flywheel seems ok, but I will give it a closer inspection, really appreciate the offer mate.

[DRIFTBOY]

For the hassle:expense ratio I'd replace it Theo.

Pressure plate could be getting tired too if it's an old clutch, and I've seen the video of how you drive it!

Once oil is on the friction material I doubt you'll get it out and it will probably only get worse - and how often do you feel this energetic ! ?

If your flywheel looks ok then I doubt my spare is any better to honest, just a thought, no worries.

Martin.

[Theo]

Clutch is pretty much brand new, I think the only mileage on it is what i've done, which is under 500 miles!

Just looked.... £140 for a new clutch kit from GSF. Looks like you can get a new clutch plate for around £75 from BMW though.