My 97 Prizm (AKA Toyota Corolla) only has 150K miles on it and the engine is getting loud. I was wondering if this was a symptom of the valves clearances needing adjusted. I read that this should be done at 60K mile intervals and has never been done on my engine. Also, should I be changing my timing belt?
Just trying to do some preventative maintenance to prevent future breakdowns.
Thanks!
Sounds like it's too late to call it preventative.
By your reckoning, the valves should have been adjusted twice by now, but were not. I'd say that the timing belt is probably overdue as well. Likleyhood is that a failure of the belt will cost you an engine rebuild, as the valves are likely to be struck by the pistons if they are held open by a non rotating camshaft.
When you do the valves, have a look at the tops of the stems. If the clearance has gotten out of hand, the lash adjussters will beat the tops of the stems, doing them damage. If they are damaged, adjusting them is not going to have any lasting benefit. If they are chewed up, it's either new valves and adjusters ($$$) or grinding the tops to dress them, and new adjusters. Of course you could always adjust and clean everything and find yourself a good deal at the carlot to trade it in on.
Cheers Trevor Jones
Check this out.
I have had excellent results using the product as I described in the engine after a flush. The lifters quiet down very quickly, and stay that way. Everything runs smoothly, and I have seen NO evidence of foaming in the oil. Oil pressure stays good - even up a bit in some cases. Air entrapment will cause lower oil pressure. Used in hydraulic systems it quiets noisy pumps - and usually air causes pumps to be noisy. I think the fine tooth gears and high speed of the test are not real-world conditions.
I'll continue to use it and recommend it for this purpose.
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