Question

If blue smoke is seen at the tailpipe when an engine is started, which part(s) is/are most likely worn out?

A thermostat
B valve stem seals
C oil pan gasket
D timing chain

Answer 1

If blue smoke is seen at the tailpipe when an engine is started, the most likely worn-out part is the valve stem seals.

Step-by-step explanation:

If blue smoke is seen at the tailpipe when an engine is started, the most likely worn-out part is the valve stem seals.

Valve stem seals prevent oil from entering the combustion chamber and causing blue smoke. When the seals wear out, oil leaks past them and gets burned in the engine, resulting in blue smoke.

To fix this issue, the worn-out valve stem seals need to be replaced. It is a relatively straightforward procedure that involves removing the cylinder head and replacing the seals.