Oil smoke only on start up ?

[Americo_Samma]

I have an 3.2 Carrera SC engine freshly rebuild, with about 500 km on it.This engine has 1% leakdown, new pistons,new guides and valves,everything is new.
It starts everyday morning with a blue smoke, only on start , nothing at the rest of operation.Details: I am using 5W40 fully sinthetic oil , level is 3/4 from full on the level gauge , pressure is normal all the way from cold to hot.
Any suggestions?

[ivangene]

I suggest you go back to who did the work and talk to them.......


I would not be overly concerned, but still worth opening some dialog with the builder so if there is something to it he/she is aware of it.

might be a ring issue, seating, a guide or the oil you are using....BTW what oil 5-40 is a funny one...is it Q-Power, most guys here run 20-50 BP or VR1

[wildcat077]

From experience,i would say that a synthetic oil for engine break in is not recommended as you need for all the parts to seat themselves and a regular mineral oil is more adequate for that purpose.
Another thing,i would not put anything less than 15W50 or 20W50 in an air cooled Porsche engine ...
I'm sure some engine experts will chime in and give you some good recommendations !

Cheers!
Phil

[Drisump]

The oil that fill most engines as they leave the factory is not the same as the recommended oil. They are usually filled with a "break in" oil to speed up the process of proper seating between the wear surfaces. You probably have to put a few more miles on her before the exhaust clears up, but as ivangene says, it may be wise to bring up your concerns to the rebuilder. BTW 5-40 is very light for these engines on an ongoing basis, perhaps that viscosity is the preferred break-in oil for your shop. Cheers

[Americo_Samma]

As I have followed and taken photos of all the rebuilding,I can rely in an oil fault.I will first do an oil change and put 20W50 mineral oil , as I agree that 5W40 is a very light one for an air cooled engine or even for an old spec. engine.

[hbf]

A long shot and a problem that I have never seen discussed here, but I raise it:

I have the same problem on my 2.4. Blue smoke only on start-up. But only if car has been standing overnight. Oil consumption within specs. Compression and leak down within tolerances. The only other thought is that there must be a leak from an under-piston cooling nozzle. If my thought is correct then a little oil will accumulate in a cylinder after the engine is stopped and will burn off immediately after start-up.

Such a problem is the opposite of a clogged nozzle, which seems to be a common issue. Perhaps the opposite can occur.

[john walker's workshop]

smoke on start-up= you own a 911. be happy, and go for the 20/50.

[Flat Six]

Originally Posted by Americo_Samma

. . . level is 3/4 from full on the level gauge . . . Any suggestions?

Yes: don't rely on the gauge to determine oil level -- use the dipstick (idling, on level surface).

[ivangene]

"As I have followed and taken photos of all the rebuilding,I can rely in an oil fault."

was that meant to be understood?

I hate to put the brakes on your changing of the oil.... but you seemed to jump right on the "mineral oil" without a thought....

again, I recommend TALKING to the rebuilder (unless it was you) then since it has some miles on it, consider going to the more common oils as suggested here

[nesslar]

All sounds good. I would suggest trying to let the car idle for maybe 10-15 seconds before shutting it down. Seems to help some folks. +1 on JWW....lol, I might add.

[lindy 911]

Your smoke could also be a rich start up condition which has nothing to do with oil. Might want to check the settings.

Lindy