Valve adjustments on '91 accord

Does anyone know how often the valves should be adjusted on a '91 accord and
is it even worth while? My accord has around 264,000kms on it and for the 4
years I've had it I have not adjusted the valves, and yes they do make a bit
of clattering sound when under heavy load (say driving up a mountain road)
but wouldn't that be just because it's old? Any tips or ideas?

 

Most mechanics recommend that valves be adjusted every 50,000 miles. Many
people also have their timing belts changed at the same time. Obviously,
there are others that have different points of view. I believe you should
have your valves adjusted ASAP and also change out your timing belt. If
the timing belt breaks while you are going over 50 mph--it can cause
damage that is very expensive to fix. If your vehicle has a timing chain
instead of a belt--change it now if it has never been changed before.

 

Valves should be adjusted after an overnight cold - engine
not run at all. Because dimensions that change with engine
heat will cause improper adjustments.

I have never had valves change more than 10 minutes (on the
clock) over the entire life of a Honda engine. However I did
find one Honda engine where the mechanic so badly backed off
the valves as to require 45 and 60 minute turns of that
adjusting screw. Worst valves were where he would have had a
more difficult time getting his feeler gauge around
obstructions and between rocker arm and valve stem.

I then take valve adjustment one step farther. Run the
engine hot. Measure those new valve lash adjustments for a
hot engine. Any valve that has varied significantly from the
average of all valve lash is then adjusted about half way to
that average. Then confirm those changes have not been
distorted because car has cooled in meantime.

If you adjust all valves by no more than 5 minutes, then it
is not worth while. But those valves that required 45 minute
adjustments were quite loud. How could that mechanic not know
he had screwed up a Honda. Was he deaf?

 

Your "valve clattering" when driving under load up a mountain road could be
pinging. Try using higher octane gas. Pinging can be very destructive for
an engine. On another note, many shops recommend adjusting the valves every
15,000 mi. (24,000 km) However, it's been my experience that this can be
extended to 30,000 mi. (48,000 km).

Eric