M54 - Oil line to cam-chain tensioner ???

[clipper]

I have put my 525i into a trusted local indie today because I just can’t see where it’s leaking oil from (apart from a rocker cover weep which drips on the manifold, but there’s a bigger leak somewhere else), admittedly I haven't looked that hard....

They have come back saying that there is a ”asignificant”a leak from a pressurized oil feed to the cam chain tensioner and it needs a new hose.
I’ve seen this kind of set up on other engines (on my GSXR 750 for example) but I didn’t think that an M54 has this? I reckon they are referring to the oil feed to the VANOS unit.

Does it sound like a reasonable cause for a car to drip 7 or 8 drops of oil after being parked 45 minutes?

[Simon13]

yes the vanos functions through having high oil pressure feed, if you get a leak in this area your going to know about it!

[clipper]

I've suspected for a while that the Vanos wan't working properly. I even almost bought a seal repair kit, but I'm glad I didn't now. I'll wait and see if this new hose fixes both the oil leak and the Vanos operation!!

Just to confirm though, there is no oil hose to the cam chain tensioner is there?

[bss325i]

No!

[DanThe]

Ive never known a vanos oil feed hose to leak!

[bss325i]

Ive never known a vanos oil feed hose to leak!

I was going to say that.

[Demlotcrew]

I have seen two vanos hoses leak at the vanos side! (where they are crimped).

[bss325i]

Interesting.

[B7]

Oil pump housing? More common ailment on thes.

[DanThe]

Ive seen rusty and slightly damp ends, but never a leak as in drip drip drip

[Ajsingh]

Ive never known a vanos oil feed hose to leak!

+1

The M54 is a great engine and the ones iv worked on have hardly any or no leaks

[bss325i]

The most common oil leak on an M54 is the cam cover gasket and normally starts at the back.

The rubber seal goes hard like plastic!

[clipper]

The car went in for a service a year ago and they checked the oil filter housing seals becasue it was dripping oil, but that was all OK. At the time they said that the filter had been poorly tightened and was causing the drip.

After the service it didn't drip for a while. Then I noticed the famous oil burning smell from drips onto the manifold and shortly after small puddles on the floor again. That's why its gone in again.

They say that the filter and housing are still OK but the cam cover is weeping (I knew it was) and that the oil hose is leaking, causing the drip.

They should have fixed both issues by end of today, I'll ask them for the old hose to see where it has failed.

Thanks for all the help (I hardly do any work on the E39 as it's my wifes daily and we can't afford for it to be off the road from one weekend to another for lack of time / parts /tools) which often happens with my E30 and motorbike !!

[clipper]

It was indeed the high pressure feed to the Vanos which was leaking, but through the crush washers. The pipe itself was not replaced.

Cam cover gasket also replaced and it appears to be virtually oil-tight again !