911 smoke on start up

[porcha]

My question is. Is there a way to stop a 911 air cooled engine from smoking at start up? It is just a puff and it clears. The mechanics tell me it is normal. I realize it is a horizontally opposed engine and oil leaks down inside the cylinders. It was suggested to run them a quart low.
I have had 2 911s and 4 944s. 944s never smoke on start up. Please excuse the dumb question. I have been without a Porsche for over 8 years, I am thinking about buying a 964 C2.
Thanks in advance.
CK

[Steve@Rennsport]

CK,

There are several reasons why these engines can emit smoke at startup. One must first determine if the smoke is blue, white, or black in order to begin the diagnosis process.

Your mechanic offered some sound advice IF he gave the context for his statement.

Fact is, very very few people truly understand these dry-sump oiling systems and tend to maintain their oil levels (hot) at or near the top mark on the dipstick. In some cases, people unknowingly overfill the system by not allowing the oil temp to get up to operating temperature before making a decision about oil level. Adding oil when the temps are below 185 deg F is a sure cause for excess smoking.

964's are really good cars and I would recommend availing yourself about these engines and reading up on them (the owner's manual is a great place to begin) so you understand the systems and differences.

One quart is inconsequential in a system that holds 14 quarts.

[mdripley]

Yes over filling your oil will cause smoke and crummy performance.
I had to drain about one and a half quarts of oil. I will no longer use the oil gauge for oil level. Considering this car sat in my dad's garage for a couple of years, I may needed to clean the oil tank level sender or replace it.

[DohertyCM]

Fill the oil tank until it just touches the dip stick....bring the car up to temp and then check it.
Not all are the same...or act the exact same way. Work with it and add a little at a time until you figure what level is good for your car.

Smoking on start up after the car has been sitting awhile is normal. As long as it stops shortly after...if it doesn't stop then you could have issues.

[Scargo2]

Back in the day (80's) it was common to leave out the exhaust side valve oil seals. Reportedly it was an extra 5 HP. If that was done you had a littler more smoke at start up.