Inconstant Cold Start Up Smoke

[landtoy80]

My 94 Land Cruiser 392,000 mi, has had cold inconstant start up smoke for the last 100,000 miles or so.
That is, some times when starting cold, I get a blue cloud of smoke and other times starting cold there is no smoke. The length of time and outside temp and the same when it does and doesn't produce a blue smoke cloud. Its not a big cloud and it goes away fast.

Could it be that the motor has to stop at a certain location for there to be oil leaking past the valve seal? Assuming its the valve seals that are leaking. Having never worked on valves or heads, could there be a warn spot on a valve stem instead of a worn valve stem seal? Or is it normal for leaking valve stems to only leak at certain points when the motor stops running?

 

[Donald]

Well its likely some but not all of the valve stem seals are leaking. Then depending upon what part of the 4 cycle a given cylinder is on, the oil gets burned or maybe pushed out into the exhaust unburned.

If it bothers you, its not that expensive a job to have them replaced. And you valves will be in perfect adjustment after.

Its likely to become more consistent as they will all probably leak or crack apart.

 

[landtoy80]

I pulled the plugs and put a gun cleaning patch in and wiped it around and all I got was carbon, no oil. Over the last week or so, I have had no start up smoke. Strange.

 

[SteveSRT8]

Check your intake manifold. It is likely full of oil from the PCV.