DIY oil change-my job failed.

[4zwmb]

Update:

And two, if no leaks will happen, how could a seal from comline do the job and a bosch seal fail like this?

Bosch are like all other manufactures and can make or buy in dodgy components, at least you have sorted it now

Well I can t really be hundred percent sure I have sorted it out now because the first time I put on the bosch seal I drove for 15 miles with no problems at all and then two days later I was driving it again, this time for more miles and ooops, leakage again. Lets just hope history won t repeat itself when I test drive it again in the coming days.

I agree with you that bosch can make dodgy components but I looked in detail at the seal when I was going to replace it with the seal from comline and to me it had no flaws at all.

[flybobbie]

Would be surprised if any well known brand actually make filters.
When you see the cross references on some sites there can be like 30 brands.
Doubt if there's thirty factories in the World that make filters.

Well here's ten, I suppose the World is a big place;
http://top10bestbrands.com/top-best-oil-filter-brands/

[4zwmb]

Thanks for the info and for the link flybobbie. This weekend is going to be sunny so I am waiting to give my z4 another good test to ensure the leakage problem has been eliminated. I will update you guys later on.

[Mike6]

Could someone have overtightened the filter cover and put a hairline crack in it?