|Drop in compression
Question : I drive a Honda Accord CA5. Recently I sent the car for a compression
check, and it seems the result shows that it has dropped from 150 bar to 100
bar. The mechanic told me to grind the valves to get back the original
compression. What are the parts involved in the procedure, and how long will
it last once I grind the valves?
Answer : Unless the mechanic did a proper wet and
dry test, he has no way of knowing if the loss of
compression is because of worn rings and pistons or valve seats. What he probably wants to
do is to remove the head and do a valve job and
then check the pistons for wear and then tell
you the bad news when the head is off. I would
suggest that you be sure of what needs to be
done before taking the head off. If the car has
built up quite a lot of mileage I think the rings
and possibly pistons may need to be replaced.