Question : OF late, the engine of
my Mazda 626 is starting to sound like a diesel engine.
Though it runs great, the sound is annoying and worrying.
Answer : Sounding like a diesel engine may mean that your timing chain
is loose because the tensioner is not working or else the valve clearances have
become very large and you are having what is known as "valve clatter".
In both cases, you need to check the engine and all the timing and valve