Oil leak from number 1 cylinder oil return

[bmw320iSE]

hi guys i got a m20b20

bought it with an oil leak a few months back

at first thought the oil was coming from front camshaft seal so replaced it and it was still dripping oil so then moved on to headgasket replaced that and it was still leaking from same place just under the cylinder head on number 1, the corner of the block running down the front and dripping off the sump (also changed the belt and tensioner this time around)

so after a couple of weeks of putting up with leaving oil puddles everywhere i stripped it all again, bought all new gaskets required, had the head skimmed, new bolts it was fine for 2 weeks and now its leaking oil in exact same place

im beginning to get a bit fed up with this now

could the block have warped or something??? i cant see it has but ive had the head skimmed new gasket,bolts, correct torque and its still leaking so only leaves block in my book.

Losing faith might just go buy some euro diesel shitbox

[Brianmoooore]

What make of head gasket did you use? This is a common place for leaks to occur with less than top quality gaskets.

[bmw320iSE]

What make of head gasket did you use? This is a common place for leaks to occur with less than top quality gaskets.

Goetze, looked of good qaulity

[daimlerman]

What about the 'half moon' shaped rubber thingy's at the ends of the rocker shafts?

BTW,an M20 that does not leak oil,is an M20 with no oil in the sump...

[Ajsingh]

Rocker cover gasket changed?? Its a basic thing item but can cause this issue.

A front crank main oil seal, im not sure if these are an issue on e30's as haven't really heard about it on e30's. Could be a possiblity tho

[bmw320iSE]

What about the 'half moon' shaped rubber thingy's at the ends of the rocker shafts?

BTW,an M20 that does not leak oil,is an M20 with no oil in the sump...

Checked them there flush with the top of the head and pushed down as far as they will go and are in good nick

Rocker cover gasket changed?? Its a basic thing item but can cause this issue.

A front crank main oil seal, im not sure if these are an issue on e30's as haven't really heard about it on e30's. Could be a possiblity tho

Havent changed the rocker cover gasket and i am pushing my luck with it but dismissed this as it all stopped leaking for 2 weeks when i changed the head gasket

crank seal is alot lower than the top of the block unless anyone knows of oil traveling up instead of down then i cant see this is the problem

i changed the oil for 5-40 fully synthetic castrol edge oil after i thought i had fixed the leak, it was fine for 2 weeks so cant see this is the problem either??

thanks for replys much appreciated

[daimlerman]

I attach the rocker cover gasket with 'No Nails' to the cover and I use 10w-40 oil.

I had a 25litre barrel of 5w-40 on the go for the beniefit of a more modern car a while back and found that the M20 spat it out in disgust...with 10w-40 it drops perhaps half a litre between changes.These engines are rarely either silent in operation or completely oiltight,so unless it is dripping an unaceptable amount do not worry too much.

[bmw320iSE]

unfortunately im leaving too much of a puddle everynight to leave it

[daimlerman]

unfortunately im leaving too much of a puddle everynight to leave it

Then we have to fix/reduce to an acceptable level.

When you had the head off,did you have it skimmed?

[Rav335uk]

I attach the rocker cover gasket with 'No Nails' to the cover.

Are you OK malcom using that, surely a new gasket should seal everything nice and tight

[daimlerman]

I attach the rocker cover gasket with 'No Nails' to the cover.

Are you OK malcom using that, surely a new gasket should seal everything nice and tight

I'm a known tight git,rav,this seals the gasket to the cover(then you wipe off any surplus,of course)and allows the gasket to seal to the head properly.
It also allows the seal to be broken repeatedly to allow for rocker adjustment without the need to replace the gasket because it has stuck to both the rocker cover and the head,in different places,and therefore split!

[Rav335uk]

Mine has never split will doing what you have

[bmw320iSE]

unfortunately im leaving too much of a puddle everynight to leave it

Then we have to fix/reduce to an acceptable level.

When you had the head off,did you have it skimmed?

some how missed this reply sorry

yes I had the head skimmed done everything by the book so not too happy ATM what Bout 20-50 oil or something?

[daimlerman]

Not sure that will help,after all,it's leaking when cold as well as when hot,so a thicker oil will only reduce the dribble/leak when cold?

at the front end of the head there are oil joints;
head/block
head...rocker shaft ends
head/rocker cover
head/front end of cam

My gut feeling is that we need to be certain of exactly which of these is the culprit,then decide the best way to seal it.

[spic]

where did you get with this ?

[bmw320iSE]

I gave the head bolts another half a turn on all - carried on leaking when got up to temp

so left it for while and after driving to my girlfriends (15 mile drive) it dropped a rather considerable amount of oil outside her house

so i got it home took the cam cover off checked all seals degreased the the cam cover gasket "hylomar'd" it all up, then noticed oil all over the other side of the block underneath the intake mani so took the intake boot off to gain acces and cleaned everything up bolted it all back together and fired it up and watched the oil spilling out from the crankcase breather pipe

now i havnt had a chance to take it off but ive only ever had it off when Ive took the head off, im assuming you can get this off without taking the inlet manifold off? and im guessing its just an o ring thats failed? or are the other common problems?

thanks for the help.

[daimlerman]

I have had this as well!

You will have to remove the inlet manifold to effect a proper repair.

You need a pair of 'O'rings(top and bottom of the tube)and the big washer that fits at the bottom,over the 'O' ring.
Compress the spring with a couple of cable ties and fit up the lower end,letting the tube sit low in the crankcase.
Re-fit the inlet manifold with nice new gaskets.
Cut the cable ties and carefully guide the top of the tube into it's location.

Do make sure that the breather tube is spotlessly clean inside and out.

[bmw320iSE]

I fitted a breather filter to my cam cover and blocked off the tube on the Tb before my oil leak

could this have been the problem with the oil leak ?

[daimlerman]

I fitted a breather filter to my cam cover and blocked off the tube on the Tb before my oil leak

could this have been the problem with the oil leak ?

Try reverting to standard and see if it stops,but this is the point in the oil breather that a 'catch tank' is fitted by the racing lot,I think....so I cannot see why a filter would increase crankcase pressure enough to force the stuff past the O rings.

[bmw320iSE]

I fitted a breather filter to my cam cover and blocked off the tube on the Tb before my oil leak

could this have been the problem with the oil leak ?

Try reverting to standard and see if it stops,but this is the point in the oil breather that a 'catch tank' is fitted by the racing lot,I think....so I cannot see why a filter would increase crankcase pressure enough to force the stuff past the O rings.

This was my thinking about the pressure pushing past the o ring

Anyway i have drained the old fully synth 5-40 oil, sealed the crankcase breather o ring at the bottom, reverted back to original breather pipe linked back up to the TB and put new 15-40 part synth oil in and no major leaks as of yet, it will be getting a 30 minute drive later this evening so will find out then but so far so good

And then i gave it a massive clean and a little polish for being so kind

One slight problem which is kinda big i dont think the fans working whats the best way to test this without doing any damage? its a viscous of course.

[kman82]

I've got a similar issue with oil leaking down my oil return pipe. I'm going to take off the inlet mani to see if i can put it right. I remember stripping all this down a few years back to change my injectors so its a fault i've introduced. Cant see what i would have done wrong though.

can anyone give me some tips on how to locate the top of the pipe properly to get a good seal. I will be making sure everything is spotlessly clean. Should the O rings be wiped in oil first maybe? I'm struggling to picture it all at the moment but should the O rings be fitted to the pipe first or located on the u/s of inlet mani?

cheers

[DanThe]

I fitted a breather filter to my cam cover and blocked off the tube on the Tb before my oil leak

could this have been the problem with the oil leak ?

Yes, 100%

The breather is piped to the intake to put a vacuum on the crankcase, by removing this you now have pressure

[kman82]

I've got a similar issue with oil leaking down my oil return pipe. I'm going to take off the inlet mani to see if i can put it right. I remember stripping all this down a few years back to change my injectors so its a fault i've introduced. Cant see what i would have done wrong though.

can anyone give me some tips on how to locate the top of the pipe properly to get a good seal. I will be making sure everything is spotlessly clean. Should the O rings be wiped in oil first maybe? I'm struggling to picture it all at the moment but should the O rings be fitted to the pipe first or located on the u/s of inlet mani?

cheers

No one got any tips for me?

[Brianmoooore]

New O rings, make sure they are well lubricated when fitting, and check that the top of the pipe goes fully in - just basic good practice.

[kman82]

Gaskest and new O-rings arrived today. Should i lubricate O-rings with wd40?

[daimlerman]

Gaskest and new O-rings arrived today. Should i lubricate O-rings with wd40?

I would 'borrow' a saucer or an eggcup from SHMBO and soak the O rings in engine oil for an hour or two.


Do make sure you remove all traces of oil before returning your borrowed gadget!

[Brianmoooore]

Should i lubricate O-rings with wd40?

No - will probably evaporate before you get things together. Use engine oil, or better still, a smear of silicon grease.

[kman82]

Thanks. Shmbo lol