Oil leak near head.

[QuattroMark]

My A6 (AUK engine) uses quite a lot of oil - I removed the undertray to see if I could see where it originated from - the tray was soaked!

However, after a week or so of driving and parking overnight there was no sign of oil on the floor but quite a lot on the underside of the car, even though I had received a low oil warning earlier. Its possible it is only losing while driving.

While I was doing a service on the car I noticed that the vacuum pump was covered in oil and grime as were the pipes underneath the pump - I bought a seal kit for the pump and fitted it thinking this was my problem.......unfortunately not! still getting oil warning indications.

After a little more investigation and removing the whole air intake section i noticed that the rear part of the drivers side block was soaked in oil.

Looking at 7Zap there is the rocker cover and a gasket, the camshaft frame and gasket and the head and gasket. Its difficult to see exactly where the oil is coming from, but seeing as though I have no performance issues, water loss, oil in water, water in oil etc I'm thinking (hoping!) that the head and gasket to the block is ok.

I don't particularly want to remove the head, however, I have noticed smoke from the exhaust when I hit the gas after cruising downhill using engine braking only - this I think is valve stem seals letting oil pass - I am presuming that the head has to come off to replace the stem seals?

 

Anybody had experience of camshaft carrier and head removal? - 

 

thanks

 

Mark

 

 

 

[Steve Q]

Think you're just going to have to bite the bullet on this one and remove the head. You may as well changed all of the seals for peace of mind and to prolong the cars life. 

[Magnet]

Hello Mark,

It’s unusual for head gasket failure -in itself - to cause an oil leak, unless the gasket has failed (only) around the oil feed to the head, so personally, I would not go tearing the head off without some independent actual-car inspection. 
The symptom of blue smoke on the overrun is typical of valve stem/ guide/ seal wear, and if you want to rectify this, then yes, the head would need to come off, and seals only, may or may not resolve that, but from your post, it appears that the car may be leaking more oil than its burning, so I would be getting back to basics and getting some on the ground assistance in tracing that first. 
Kind regards,

Gareth. 

[QuattroMark]

Thanks for the replies - 

Looking closer I think the leak is from the gasket between the head and the cam girdle - the question is.....do I take the head off as well while I am there so I can replace valve stem seals...or better left alone - and then also, do I replace top chain tensioners while it is all apart - 

 

This could go downhill very quickly!!

 

Mark

[Magnet]

Hello Mark,

Pardon my ignorance of the layout of your particular engine, but V6 usually equates to two separate cylinder heads. So if you are removing one? - to renew the valve stem seals, what about the other?? 
As I’ve mentioned, renewing seals on their own may result in only a temporary improvement if the valve guides/ valve stems are worn. 
Couple this with the question ( already raised) - how much oil are you leaking as opposed to burning? - would still lead me to question your logic of removing a cylinder head.

Kind regards,

Gareth. 

[QuattroMark]

I get what you are saying - but whatever happens I have to fix the leak on this particular head - and the evidence is there regarding the overrun, so i was thinking it maybe prudent to change stem seals ( and check valves) at the same time considering the amount of stripping down i'd have to do anyway - once that bank is done I would do the other.....the car is an absolute workhorse, close to 200K miles now and it is one of the best Audis I have ever owned - and i'd like to keep her running. 

best,

 

Mark