Can't see oil leak source

Yes .

 

+1

 

Check out the valve cover gasket too—it might be the troublemaker around there. Look for leaks or anything odd. Sometimes, those leaks can look like camshaft seal issues.

You could also try using a UV dye additive in your engine oil. Let the engine run for a bit, then bust out a UV light to inspect the area. It's a neat trick to zero in on exactly where the leak is coming from.

 

The camshaft has a rotary type seal in the seal carrier just behind the toothed pulley which the shaft pokes through and connects to. But just behind that in the cam cover itself there is also an O ring that forms part of the seal of the cam cover to the head, and that can be the source of the leak. This happens as a common leak area at the junction of this O ring to the paper gaskets that also forms part of the cam cover sealing, the paper can cut into the O ring.

Having just dealt with this (I replaced the O ring and cover gaskets successfully curing the leak), I initially sprayed some degreaser to remove the oil weepage, put UV dye in the oil as the other post noted, and then drove a bit to see where more precisely where the leak source was. I too thought it was the camshaft rotary seal, but it was the O ring to paper gasket junction area.

As a last ditch effort, I snugged down the cam cover nuts (not too much, they don't take much torque), which did not solve the leak. I then tackled the cover removal and O ring replacement. Fixed the leak, and the rotary seal was fine and did not need addressing.

The rotary seal replacement requires camshaft removal, and one typically ends up doing timing belts, valve adjustment, etc. The O ring replacement is ideally also done with camshaft removal, but there is a bodge which also works depending on ones goals.

Hopefully you can trace the leak to a trivial cause. But these seals/Oring/gaskets are a fairly common leak source as heat cycling and rubber hardening takes its course as the mileage racks up.

In an ideal world these seals and gaskets are preventively renewed are part of the full "major" services that are called for. But as often they are dealt with when leaks present.

 

There's a modification that can be and should be done around the camshaft seals, it involves drilling a hole with a specialized rig to prevent future leaks, Daniel at Ricambi loans/ rents the kit to perform this modification. From what I understand the factory started doing this mod and you can tell by your serial number if it has been done. I just had a major done on my car including replacing the camshaft seals and a lot of other things and this modification had already been done to mine, worth checking.
Alden

 

This was an ongoing issue when I had my QV. Wade at Merlin - who posts here, had a good technique to keep the seals and gaskets from leaking. I think they used this white sealant that Honda uses - over and below the gaskets? I think. on my car, it worked most of the time... but over time with all the heat trapped by the front of the engine, they tend to weep a bit of oil. what I hated was that haze of blue smoke that wafted up at Traffic lights. I Think Wade goes by Ferraritech here on FChat...

 

Extremely common. and annoying.

 

My 88 328 has had this problem, according to the service records, since it was almost new.
Previous owners/garages had tried that white sealant to support the O ring sealing. It may have worked for a while, but not more than a few k miles.
Folk have also tried to short circuit the repair by cutting then feeding new O rings around the carrier grove (saves removing cams) that the O ring sits in. This also hasn't worked for very long, perhaps because there is white sealant in the underside of the carrier, which can't be removed without taking cam out.
So this time I'm fitting X rings, no sealant in the groove. Just a dab of sealant where the cam cover gasket butt's up close to the X ring. They worked a treat when i replaced the leaking shift shaft seals, so hopefully will fix this issue.
This has been the only area of leakage on mine. The rotary shaft seal and cam cover gasket have always held up well.
I am also replacing the distributor end rotary seal with a Viton one. Hopefully this will extend life of that seal. The nitrile seal that was in there must have been running quite close to its max temp limit.
It takes two people, but well worth removing the hood when doing this repair. Access is opened up an incredible amount!