oil leak question for experts

[j930]

on my 84 930 with 37K miles I have had every hose that you can get to replaced. I have a small oil leak on the drivers side that drips maybe the size of a quarter. I had a little seepage from the oil tubes so I replaced them last week. now I have a little less oil but still a drip. it appears it is coming from above and it makes it way down between the oil return tubes. my mechanic diagnosed it as the cam tower. any thing else to look for?

[fastfredracing]

I'd be taking a good look at the rocker arm shafts

[JFairman]

most of the time it's a rocker shaft leaking and there are 3 rocker shafts and 6 rocker shaft ends that could leak in each cam tower. no way of knowing without cleaning the rocker shaft ends of any oil and dirt, then driving it a while and going back and looking and feeling the ends for oil.
the ends of the rocker shafts are exposed to air, so the air coolinbg flow can spread the oil around a little if it's leaking from there.

often times the aluminum rocker shaft bores get scratched or scored when someone uses different tools and tactics to pry and push out the rocker shafts to remove them if they are stuck in there and then they leak at those scratches when new or used rocker shafts are back in and running.
overpriced rubber rocker shaft seals can help stop those leaks.

rocker cover removal both times is required and this is probably misdiagnosed alot, and more so by mechanics looking forward to racking up big labor charges.

it could be the cam tower loctite 574 or threebond or whatever sealant/glue between the cam tower and cyinder heads is leaking but alot of cleaning in the area of the leaking and then running the car till fresh oil leaking occurs is required to diagnose it.

[copbait73]

That engine is only 37K miles but it's also 27 years old. Go down to the auto parts store and get a vial of oil leak dye check. Clean the engine as best you can with some brake cleaner and rag. Add the dye, drive it again in a normal fashion. Jack it up and use a black-light to see the new oil traces.

I think with the engine's age you may find the oil is really coming from the large o-ring seal behind the cam sprocket. Those o-rings don't stay resilient forever. It is not logical oil can get out here and go toward the driver but it does because of the airflow and castings.

[JFairman]

the orings that go around the cam thrust plates and seal against the cam holes in the chaincases mentioned in the above post are made of silicone and silicone does stay soft and resiliant for a very long time.
those orings usually don't leak unless they are installed incorrectly or pinched and cut while installing with no silicone oring lubricant, curil T, light coating of hylomar, or grease on them.

if the heads were flycut or spun in a lathe and milled down and the chaincase is not machined down the same amount as the heads where it mounts to the case then the cam thrust plate will be of slightly off center to where it bolts to the cam tower.
moving the thrust plate a little sideways to compensate and bolt to the cam tower with it's paper gasket will squish one side of the oring and the other side will be loose and the loose side may leak oil.

i think supertech makes different thickness shims you can put in between the heads and cam tower to space the cam tower back out to where it was before the heads were resurfaced or machined. That will keep the chain length the same and make it so the chain cases don't have be machined down the same amount as the heads where they attach to the case.
depending on how well those are installed with 574 or threebond they can leak oil too.