Help lots of smoke

[gold911]

1979 911 SC
While driving down the freeway, if I decelerated for 10 seconds and then accelerated, the car blows a cloud of smoke so large that it engulfs the cars behind me, then stops. It will do this time after time. This issue happen all of a sudden and the car runs great with no power issues. Normal acceleration or startup produces very little smoke if any.
Can anyone assist with figuring out what is going on.

[kodioneill]

Check your oil level with engine warmed up on level ground with the engine running. The oil level should be just above the bottom line about 1/2 inch.

[Targalid]

This sounds like the classic test for valve guide wear. Slow down from high rpm then accelerate to check for oil smoke. If yes, then you likely have worn valve guides with oil sucking down along the valve stems. You will still have plenty of power but ultimately worn guides can lead to uneven valve wear in the valve seats and then burnt valves.

[jmod]

I had the same problem with my 79. Ended up being too much oil. I had to take 2 litres out of the system. Some mechanics don't know how the dry sump works and just fill the system right up to the top line even though there is a nice label that spells it out for them.

There are a few older posts on this subject which are worth looking up.

[Dantilla]

Originally Posted by Targalid

This sounds like the classic test for valve guide wear.

+1.

Lifting off the throttle produces quite a bit of vaccuum in the cylinders, which sucks oil past the valve guides. As soon as you step on the gas, this oil burns, producing smoke.

[Joe Bob]

Carrera 3.2s are mostly known for that....but a few 3.0s have had the issue. I vote the high oil thingy before slitting your wrists. EVEN IF it's guides....you can delay the sting by oil viscosity adjustment.

Synthetic or dino? Multi weight or single....lots of questions before a tear down.....BTDT.

[gold911]

thank you for your replies. Oil level is at the lower end of the dip stick, so not over filled. This issue happened all of a sudden. Is there something that is plugged that would suck oil into the intake. This is a lot of smoke

[Winter]

Originally Posted by Joe Bob

EVEN IF it's guides....you can delay the sting by oil viscosity adjustment.

Synthetic or dino? Multi weight or single....lots of questions before a tear down.....BTDT.

I am fairly certain that I will have to address a worn guide issue, although my smoke problem isn't this bad. However, I'm interested in driving for a bit this summer before dropping my engine, with that in mind, what oil viscosity would you suggest to "delay the sting?'

Thanks in advance for the help.

[Joe Bob]

Try straight 30 or 40w.