Toyota Repair: Blow By- engine, worn piston rings, coolant leak

Question
I hjve a 86 Toyota Camry with 146K miles. Yesterday I discovered I was driving in a cloud of exhaust smoke. White smoke coming from tail pipet. It contiuned for 45 mile commute.
I have it at a mechanic todya- he said it has blow by, and needs a new engine.
What is blow by?

Answer
White smoke indicates that there is a problem with the headgasket or some other coolant leak into the combustion chamber, blowby is caused by worn piston rings or cylinder walls and will produce a blue smoke, in either case it means major engine repairs, I would look for a used engine from a salvage yard, this can save a lot of money, unless you wish to spend thousands of dollars on an 18year old car that may be worth $1000 in good running condition.
A good rule of thumb is don't spend more money on  car repairs than it's fair market value, generally speaking.