Any input on this matter would be appreciated.
 

Hi everyone. I've been lurking around and decided to finally join the forum.

I own a Porsche 911SC (1980). I bought it almost 20 years ago and i had the engine rebuilt about 10 years ago. After that, it just sat in my garage for many years without use(don't flame me). When i tried to start it up recently, it burns oil. A LOT. Blue smoke out of the exhaust and won't stop. Could it be the PCV? Any input would be appreciated..

PS- I was thinking it could also be the valve guide seals.

Most likely over full of oil. Drain or suck some out. Checking oil is done on level surface with engine idling after the engine is fully up to temp. Oil level should ideally be about 1/2 way between the two marks. When the car is running, what does the oil level indicate. If it is all the way up and never comes down to the red, there is too much oil.

Welcome Aboard Brother!

No worries, we are here to help :D

Check the oil when she is hot, on level ground and at idle. After a good drive and hot, get on level ground wait about .5-1 minute to let the oil settle down and check the level at the dip stick. Make sure the e-brake is up and locked.

It must be between the full and low mark, if too much as PP stated drain some out when cold.

http://forums.pelicanparts.com/uploa...1310498189.jpg
Proper Operating Temp would be about 1/8" above first HASH mark 194-200 degrees

Jim

I'm guessing after 20 years of ownership he knows how to check the oil.
I think an Italian tune up will get rid of the smoking. Prolonged sitting will sometimes pool oil in the cylinders.
How extensive of a rebuild was it. New valve guides, head studs?

+1 on an Italian tune-up..run it through.

My brother just picked up a 911 with a rebuilt engine 20 years and only 6,000 miles ago. Took it to the mechanic for checks and pretty much just needed to run out the bad gas

I'm not sure if this can happen with a stock 911, but in my 911 race car the oil from the tank slowly percolates from the tank into the engine sump over time. The result is that oil eventually rises above the bottom of the cylinders, and oil gets past the piston rings and into the combustion chamber. So next time I start it up, it smokes like crazy for about 5 minutes. Once it's running the oil pump empties the sump, and the smoking stops once the oil burns out of the combustion chambers.

There are lots of other things it can be too, but if it's this problem, it will go away on its own after a few minutes of running, so it's easy to check.

Scott

I have let my car sit for months on end and I kill every mosquito in a mile radius when I start it. Takes about 15 minutes to clear and if I use the car more often no smoke at all.

I figure some seepage to the crank case, at start up oil makes it's way into the exhaust and needs plenty of heat to clear it out.

Terry

Wow, great replies guys. It was a pretty heavy rebuild, no new cylinders or pistons, but valve guide seals, piston rings, and a whole bunch of other stuff (I still have the original receipt).

Here's the thing. I didn't say it at first because i wanted to hear some of the replies. But last fall i proceeded with dropping the engine. Took about 5 hours, didn't think it was too bad. I needed to do a lot of other crap anyways, like new firewall insulation, plus the engine AND the transmission case was drenched in oil. The heat exchangers were rusted out so i bought another pair, too. I now have the engine sitting on an engine stand. I have not really begun to get inside of it yet. What do you think i should do at this point?

I'm confused, but I'll comment anyway.

If its on the stand, pull the covers off and check all the head studs. Do a valve adjustment. If you are concerned that the motor is bad you can pull various covers and use a bore scope to have a look inside. Pull the timing chain covers and check the timing. If its all ok put it all back together, fill with 10 quarts or so.

If you have not drained the gas tank you should do that and re-fil with fresh gas and injector cleaner. Make sure the tires have correct air.

Turn it over with a wrench a few time to get some fresh oil in the pump.

Start it.

Check the timing with a timing lite.

Take her for a short spin to get it up to temp. Return to your garage and set the oil to the correct level. Take her for a grand tour of your surounds for an hour or more.

After you have run through 1 tank change your oil again. I have been told that the techron/injector cleaners sometimes sneak into the oil and degrade it. *shrug* could be true... might not be... I'll usually throw some in just before the oil change. YMMV.

many times with long term sitting the rings will get a bit gumed up/ stuck. I got my 71 Targa after sitting in a garage for 12 yrs and a fresh rebuild prior to that.
Agter draining the gas I put in a few gal of fresh premimum and some marval mistery oil that added to the smoke but then filled the tank.
What the car needed was to be driven, after about 500 mi it cleared.
As others reported ocasionally a bit of smoke at start up, buy just a min or so.

Good luck

My first thought. You are probably fine. Do the usual things: fresh gas, fresh oil, whatever things needed doing (valve adjust, seals to fix leak...), turn the motor over by hand. Once you get it running do an "Italian tune-up". For your first trip, take it out late at night so no one sees you crop dusting the neighborhood. If you are nervous, keep a close eye on the oil pressure and temperature for signs of something amiss. If the car has been stored for years with old gas you may have some gumming issues with fuel system. It'll probably take a few trips to get everything to settle back in.

Thanks for the input everyone. Another thing i noticed was that there is oil in the air box. I was wondering, where can i find my PCV valve in my SC? I might as well replace it, just in case. Where else would the oil be coming from into the air box?

You don't have a pcv valve in an SC, the crankcase vent goes to the oil tank. There is an oil tank vent that goes to the CIS boot.