Seafoam is the magic product that stops engine smoking.
Here is the underlying problem. With age the piston rings and piston ring grooves become filled with carbon, and can't expand out. Hence they start burning oil from the poor cylinder wall to ring seal.
Ultimately if you have the time, take all the spark plugs out and put 1/2 a cup of Seafoam in each spark plug hole and let sit for a week.
The Seafoam will soften up the hard carbon and it will start running past the rings into the oil pan.
After a week start it up get it warm and drain out that oil, it's going to be really black.
With fresh oil and new filter Add 1/2 pint of seafoam and drive it for 100 miles. Then change out that oil and go back to your regular oil changes after that.
No more smoke.
If you don't want to go through that professional method, just put 1 pint of seafoam In the engine oil and take it out and drive it for 25 miles. Then let it sit for a week as the seafoam is in there desolving the carbon.
Then fire it up, get it warm and get that black oil out of there. Fresh oil and filter and you are good to go.
Have saved at least 5 oil smoking engines using this method. 2 of them were Diesel Farm tractors.
No more smoke. The rings loosen up and reseat to the cylinder walls.
It is good to know what actually is happening, instead of just pouring it in, hopping it works.
At your local auto parts store.
