This is called an "interference" engine meaning the valves and pistons occupy the same space but not at the same time, ... As long as the timing belt doesn't break. Every manufacturer has some engines like that and they're becoming more common. That, and all of the unnecessary, complicated computers, are the reasons a lot of us will not buy new cars. My newest is a '95 Grand Caravan and my daily driver is an '88 Grand Caravan. None of my 8 cars have interference engines so if a timing belt were to break, I would be sitting on the side of the road in a puddle of tears, but a new belt would be all that was needed. My '88 has 379,000 miles and is only on its second belt. That is asking for trouble, but heck, it ran good yesterday so why fix it today?
The best you can do to prevent future trouble is to have the timing belt replaced well before the recommended interval in the owner's manual. (I think you have a belt, not a chain, but I could be wrong. A chain won't usually break). Older Hondas, for example, had a recommendation to replace the belt every 75,000 miles, and they commonly broke at 60,000 miles. Some vehicles seem to run forever while others have a history of breaking belts.
By "valve alignment", I think they were referring to setting the orientation of the sprockets. That is a part of the procedure on any car. $2000.00 to replace just the belt seems way too high. That same repair on my older van runs less than $500.00. When a valve job is needed to replace bent valves, most four cylinder engines run less than $1000.00. I know GM is very good at separating money from their owners, but $3000.00 seems way too high. Might be time for a second opinion.
The low compression suggests you do indeed have bent valves. Also, don't kick yourself about maintenance. No amount of or lack of maintenance is going make that belt last longer. If you have a chain, they are inside the engine where they get lubricated with engine oil, but even poor maintenance there won't have that much affect on it.
Tuesday, November 30th, 2010 AT 10:16 PM