3.0 SC Burning Oil

[JohnHickey]

Everyone need advice, 1980 3.0 SC , Did oil and filter change a few weeks back, ran engine for 15 Minutes to check for leaks all ok, Did not start it again til yesterday, lots of smoke on start up which reduced a little but still heaps of oil fumes. Thought maybe on overfill the car so drain a litre or so out (having not started it) . On strart up all appeared back to normal but after a few minutes fumes/smoke returned.
Prior to this the car neither blue smoke or used any oil to speak of,
Help please, am I missing something obvious,
John Hickey

[yelcab1]

Did you drive the snot out of it for a few days?

[JohnHickey]

No the car has not been driven hard, maybe it should??

[rfuerst911sc]

Drive the car gently to get it up to temperature. Once up to temp check the oil level. If it's at the correct level go drive it like you stole it ! Do some hard pulls to redline and have some fun........you'll both benefit from this.

[Joe Bob]

Drive it at night.....

[JohnHickey]

All good info , why do you say at night, cause of the Temp?

[Joe Bob]

Old joke....people that suck oil in the intake are loath to be seen with it smoking....so, drive at night.

[porsche930dude]

did you use the same oil as it had before? Also what brand and grade? Synthetic oil seems to smoke less from my experiences

[Phil Blacklock]

Hi John,
What a coincidence!
I am in WA and have had exactly the same problem with my 79 SC
I overfilled mine a little and had the same problem-drained the tank some and still smoking but only after running for 15-20 minutes.
Stripped the vent hoses and the rubber inlet chamber, found a little bit of oil-cleaned everything, started up-no smoke.
Took it for a run and by the time I got back (30 minures) it smoking again-mosly at idle and on gear changes when its pulling a high vacuum.
Can't work out what is going on-car runs fine. Loath to believe what I am being told that it's rings or guides necessitating a rebuild (at + $10,000).
Only started burning oil after a slight oil overfill.
If you find your answer please let me know.
I have pushed the car to the back of the garage and am trying to forget about it (bought an old MX5 to get around)

Regards,
Blacksox

[FPB111]

Phil,
Idling after it is good and warm will return most of the oil back to the tank.
You don't tell if you checked for clean intake or looked at the oil level, 1/2 way between the marks on the dipstick, after you drained a little out. It could still be overfilled.

[john walker's workshop]

10 quarts with a filter gets it half way between the marks on the dipstick and about 1/2 way on the gauge (if the gauge relates to the stick). that's the recommended level when measured hot, at idle and car level. how many did you put in?

[Phil Blacklock]

When I overfilled it it was about 1cm above max.
Blew smoke.
drained about 4 litres was now below min, so topped up to min level (at idle, warm, level).Blew smoke
Had oil changed by Porsche mechanic, checked exhaust head studs (all ok).
Checked level -about 1/3 way up between min and max.
Blowing more smoke.
Removed rubber air chamber and vent hoses (2) and cleaned all (some mayonaise in vent pipe between dry sump tank and rubber chamber (sorry-don't know it's proper name)-not much about teaspoonful.No oil in intake behind the air filter.
No smoke until warm-now burning less but still burning visible amount at idle and on gearchanges after backing off throttle. Doesn't seem to burn under accceleration (although hard to tell just by looking in rearview mirror)
Ex-Porsche mechanic at work recommends I change oil again with straight 50 grade (our weather is warm mid 30's to low 40s-centigrade). Says they did this at the dealership with older motors and it made a significant difference.
Mileage on motor is unknown-bought car with no history ex-USA, but was not burning oil prior to overfill.
Has had about 2 hours running since overfill was corrected.