1977S engine oil issue

Joeaksa · 08-17-2010, 06:37 AM

Have a friend helping someone with a 1977 911S. His email below tells the story. He is more of a water cooled mechanic but is a very good tech guy.

Why is the oil not in the tank? Scavenge pump not working?

Thx,

Joe A

~~~~~

1977 911S Engine supposedly rebuilt 25k miles ago 2.7L

This engine runs well but positively BILLOWS blue smoke when started, which
clears after 15-20 minutes. The engine is started only every few weeks.
The owner has tolerated the problem because the car is used so seldom

Hold that thought....

The owner asked me to adjust the valves on general principles. In doing so I
came across something odd. During the course of the day the cam covers were
off and seven quarts of oil drained from the left side of the engine ...but
only a few drops from the right. Is that normal? The car was on all four
wheels on level on the ground while adjusting the valves.

I have to wonder if the left side lower cam cover/cylinder head is literally
filling up with with engine oil and swamping the valves. I don't know how
valve seals are arranged/designed on these engines but I can't imagine them
coping with being submerged in oil for several weeks at a time

Any thoughts on this?

ossiblue · 08-17-2010, 08:02 AM

Thoughts on this (just thoughts.)

If a car is sitting for several weeks, the oil will "flow" back into the engine from the oil tank--liquids seek their own level. There was a thread about this a while back. If this is the case (pardon the pun), the oil would be settling over the sump plate by the scavenge pump and would likely escape from the left bank valve cover rather than the right. From what is described, the amount of smoke seems excessive (valve guides, rings?) but the fact there is oil in the engine is not unusual, IMO.

Joeaksa · 08-17-2010, 08:51 AM

LJ,

Thanks for the comments. I am just surprised that there is that much oil in the one side of the engine. I would think that if it were level that they would get oil out of both sides and not just one valve cover?

Agree on the valve guide or valve seals.

Thx,

Joe

1982911SCTarga · 08-17-2010, 09:11 AM

Joe, is it possible the engine is being routinely overfilled by an inattentive owner?

Also, isn't it possible to run into odd scavenge issues if the sump plate is incorrectly positioned such that the pickup is partially blocked?

Brian

carrera turbo · 09:36 AM

this is not uncommon for the oil to drain out of the oil return tubes while rocker covers are off. the oil doesn't stay in the tank when cold at least not all of it, this is why you check the oil while hot and while running. to keep oil from draining out during a valve adjust simply jack up the side of the you are adjusting to let oil run the other way then the same for the other.

as far as the smoke goes if the car hasn't been run much and sits alot and is started with out coming up to temp. the oil could be thinned from moister intrusion from random starts and not bringing car up to temp every time. or you have some oil seeping by one of the oil rings when she sits for a long time. or as stated above valve guide seals.

cheers ed

E Sully · E Sully's Garage

Quote:

Originally Posted by carrera turbo

this is not uncommon for the oil to drain out of the oil return tubes while rocker covers are off. the oil doesn't stay in the tank when cold at least not all of it, this is why you check the oil while hot and while running.
cheers ed

As Ed stated, make sure the engine is fully warmed up and idling when checking the oil. If not done with a running engine it will definitely be overfilled. Most only fill it to halfway between the marks on the dipstick to reduce oil burning. Valves are usualy adjusted at the same time as an oil change because oil will flow out when the valve covers are off.

Joeaksa · 08-22-2010, 01:49 PM

Thanks for the ideas guys. Am working with the gent who is laying hands on the car trying to find the issue.

RoninLB · 08-22-2010, 10:44 PM

a good chance that once you see the car you'll pin the oil issue

from a leaking breather gasket to oil dripping inside the heat exchangers etc

or he could psi clean the engine and use an oil dye that lights up with a black light

pete3799 · pete3799's Garage

If the left valve cover was removed first,the majority of oil would drain out that side.
I bet if the right side was removed first the reverse would happen.
I have to ask.... how did he get under the car to adjust the valves with all 4 wheels on the ground? Is his name slim by any chance?