Oil Leak

D

darchard

Member
Hi everyone,

My 2003 Z4 has an oil leak from the engine somewhere. I had the MOT done recently and the mechanic said it looks like the leak is from the rocker cover gasket. I'm planning on doing the work myself but a friend suggested I should clean the engine block with a jet wash to check where the oil is coming as it may be something else.

Is that a good idea? I'm worried about getting high pressure water into the engine block or other components. I'm not sure how else to confirm whether its the rocker cover gasket otherwise. Any suggestions?

Also, any advice on changing the gasket would be very useful as I haven't done it myself before.

Many thanks for your help,
David
 
The rocker cover is the prime suspect when oil is high up the engine. The other culprit in the oil filter housing to engine block gasket
 
A common issue among e85 owners unfortunately David but easy enough to rectify.
Get urself a new cam cover gasket, I went for a febi bilstein one, plus some permatex gasket maker for the corners and half moons. Make sure to pattern torque when reapplying fhe cam cover.
Keep the pressure washer away feom the engine. You will risk doing more harm than good.
Usually if its a leal originating feom the cam cover it will be from the back of the engine on the driver side. When cool have a good feel for drips coming from fhe overhang where the cam cover meets the engine block.

Good luck :thumbsup:
 
CAUTION: I recently replaced my cam cover gasket and discovered that, because the rubber hardens over time, it can fracture like brittle plastic when you remove the cam cover (see image below). The shards of "plastic" then like to play hide and seek inside your cylinder head :)

20190321_182554.jpg

In the image above, you can see the spark plug wells. Your new gasket should include two additional gaskets, each one comprising three rings connected by rubber straps. On the left of the picture you can see two exposed aluminium spark plug wells (one is inside the red ring I've added). These were originally covered by one of the spark plug gaskets, but the rubber shattered as I popped the cam cover off. You can see the point of fracture alongside the stud, just inside the right hand half of the red ring.

I'm not saying you shouldn't do the job, I'm just advising that you exercise caution and ensure that you retrieve any remnants of fractured gasket before you start the engine again.
 
Indeed! Was good fun when one bit fell down the side of the camshaft when I did mine. Spent about 30 minutes trying to prise it out with some needle nose pliers and tweezers :rofl:
 
Found an old thread back where I documented all the teething problems I encountered at the start of my ownership; wayward throttlebody, oil leaks, CCV system replacement as well as many many digressions to many many off topic things :lol:.
Maybe of some use to you.....

https://z4-forum.com/forum/viewtopic.php?f=3&t=90194&start=60

Page 5 is where the cam cover gasket fix begins.

And Betty, as it was known at the beginning, has undergone a sexchange and has since become 'Benny' :lol:
 
Guys,

Thanks very much for all the useful info and advice. I’ve had a look at the rear driver’s side of the engine block and there’s plenty of evidence of oil dripping down onto the edges of the engine block (?) and a pool on the top of the suspension arm (?). I’m not sure if that will affect the suspension in any way? Rot the rubber? But I’m hoping not.

20190322_114538.jpg

20190322_114453.jpg

20190322_114612.jpg

I have to do an oil change soon and replace the oil level sender unit so I’ll schedule a couple of days in early April to get it all done. That gives me plenty of time to scour the internet for reassuring videos showing me exactly how to do it :)

Am I right that the only parts I need to order are:-
1. Rocker Cover Gasket
2. Permatex gasket maker
One of the threads mentions getting “rubber grommets, washers and bolts”. Do I need to get these? Which grommets, washers and bolts they are referring to?

I’m guessing I don’t need any special tools, just:-
1. A good socket set
2. A torque wrench
3. Something like a Stanley knife blade to clean the old gasket off?
The thread mentions using brakleen to clean the inside of the rocker cover. Should I do this?

Sorry if the questions are a bit basic; always a bit nervous doing a job for the first time. I’m looking forward to it tho.
Thanks again for your help and advice.
Cheers,
David
 
This is the £33 set I bought for my 3.0i:

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F312038329099

As you can see, it includes the new rubber washers.

You might need some needle nose pliers and a good torch to go hunting for fractured bits of gasket.

Nothing wrong with cleaning the underside of the cam cover, though it has about 150 small pockets molded into it!
 
OP, it's a straight forward job changing the gasket, lots of good advice above :thumbsup:

I have to advise the same caution as some have mentioned, the old gaskets, especially the circular gaskets, become very brittle and can shatter as you remove, take care here! I spent longer trying to retrieve a stray bit of gasket shrapnel than I did changing the whole gasket!

Basic tools and about 60-90 mins is plenty.

There is a good you tube video on this job, by user zed4me

My new gasket was £30 ish from ECP, personally I wouldn't bother cleaning under the cover.
 
I forgot to add: Once I realised the old gasket was shattering, I packed the cylinder head with paper towel to reduce the chances of bits and pieces dropping into it. I would strongly recommend that you do this as soon as you've popped the cam cover off.
 
what i would like to know is why cant bmw make an oil tight engine.. its just ridiculous the amount of oil leaks reported on these cars :thumbsdown:
 
mr.tourette said:
what i would like to know is why cant bmw make an oil tight engine.. its just ridiculous the amount of oil leaks reported on these cars :thumbsdown:
Click to expand...
It probably wouldn't be an issue if the engine weren't canted over at an angle. Maybe we need to fit longer suspension springs on the driver's side to level things out?
 
Hi all,

I thought I’d give you an update and ask your opinion on the bad news I’ve uncovered.

Two days ago I changed the Rocker Cover Gasket and did an oil change. I found oil pooling on the protective covers under the car, oil over the bottom of the engine block, the sump, the suspension arm which goes from one side to the other, pretty much everywhere. I wiped everything down as best I could with newspaper and then did the oil change.

Today I had another look under the protective covers and found they were again pooled with oil. I saw oil dripping from the bottom of the casing of whatever is attached to the the lowest cam on the drive belt (bottom right wheel in this picture). Not sure what it is.

One.jpg

There’s oil on the front (but not the back) half of the bottom of the sump

Three.jpg

And oil dripping from the rubber block just to the front end of the sump

Two.jpg

I looked at the bottom of the gearbox and that looks pretty black and oily as well

Four.jpg

So it looks like I still have one or more fairly serious oil leaks.

What do I do now? Can anyone advise where the leaks may be coming from and whether I can fix them myself? If it's the head gasket it wouldn't be worth getting an indy to do it. She's a 2003 3.0i with 140k on the clock. Hopefully I'm not witnessing the end of her!

Thanks in advance for your help and advice,
David
 
looks as if you've got a front seal gone unless it is just pouring out of the cam cover gasket, and whilst there change that multi rib belt, it's shot!
 
HAve you looked around the oil filter housing gasket to check for leaks there?
I had to replace cam cover gasket as well as the ofh gasket. (note, not the rubber ring where the oil filtersits but where the front end of the block mates with the oil filter. get a torch in there and look for signs of leakage on the honeycomb structure on the passenger side of your engine.

If it isn't this then it could be worst case scenario, as jl-c suggests - your main engine-gearbox seal.
And yes, those belts also look way past their best.

Could also be your sump gasket but I doubt it due to oil still originating possibly at the top end of the engine.

Are you measuring oil-loss. If significant then it could be worth a visit to an indy....

good luck
 
I agree with Chris_D. Take a long hard look at the Oil Filter Housing gasket. First of all you need to clean up to properly see what's leaking. Get some Gunk degreaser, spray on, brush in, hose off and blow it dry with an air line if you have one.
The alternator is mounted on a very elaborate cast bracket that is also the Oil Filter Housingmaxresdefault-1.jpgIt bolts on here, where all the oil is running fromas9.jpgI'm fairly sure all this mess in your photo is coming from this gasketOne.jpg
I replaced mine last year and it's an hour job tops to remove the alternator and bracket and fit a new gasket, and you can replace that shot-at serpentine belt at the same time :thumbsup:
 
Thanks guys,
I've got the gunk now so I'll clean the engine tomorrow and order the gasket and the drive belt.
If that sorts the oil problems I'll be a very happy man :D
I'll keep you updated.
Cheers,
David
 
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