Interference engine?

Does the 1999 Plymouth Breeze have an interference engine? My friend's Breeze recently broke a timing belt. The timing belt was replaced along with the water pump. Later was told that there was valve damage. Did my friend get hosed?

If there were damaged valves, wouldn't it be difficult to make a full rotation of the crank by hand with the spark plugs out?

 

Yes it is...........You're talikg about 2.4 Mitsubishi engine yes????..........I bought a Neon once with the same problem and had to do a valve job on her......The mechanic SHOULD have known/informed your friend that there was a good chance of deeper issues...........but probably wanted the timing belt job..........or he just was inexperienced and didn't know

 

IS the engine hard to turn by hand?

 

Not really...........and it'll be easier if you have bent valves as the cam will not have to overcome valve spring tension..........The valves will never "close'

 

The Gates catalog shows the 2.4L engine (VIN X) is NOT an interference engine. The 2.0L engine (VIN C) IS an interference engine

 

The gates catalog is an excellent authority on these matters

 

So if you didn't have a Gates catalogue, would you be able to tell if there were valve damage, like maybe a valve or two being way out of adjustment?

 

a compression check would let you know if there is a problem.

 

Can't perform a compression check with a broken timing belt, right?

 

Which engine do you have?

 

sorry, I was thinking you had replaced the belt.

but you can do a leakdown test with external supplied air.

The problem with an interference engine is, if you are lucky (if that is what you would call it) all you have is a bent valve. it could actually break the piston as well.


hey, wait a minute. From your first post:


The timing belt was replaced along with the water pump. Later was told that there was valve damage. Did my friend get hosed?

Why cannot you do a comp test now?

 

The car is not mine. My friend has since sold the vehicle after being quoted on how much it would cost to repair the damaged valves, this is after their mechanic had replaced the timing belt and water pump. The engine would not start after the timing belt and water pump was replaced.

My friend has been using the same mechanic for many years. I've never met this person or seen the shop. I was wondering if this "trusted mechanic" just saw easy money all these years.

So if the timing belt breaks, and you don't know anything about the engine, should a "good" mechanic be able to determine if there are any valve damage before blindly replacing the timing belt?

Maybe it's time to switch mechanic?

 

If I was the mechanic, I would have been very embarrassed to ask for payment, in light of that.

 

but you did not pose that scenario. You asked how to check for damage and you gave the scenario that the belt had been replaced. I answered properly based upon that.


So, how to tell if there is damage prior to replacing the belt? I can suggest several things but the only ones that can assure you that there is no damage would cost more than replacing the belt (on a typical car) and cranking it over.

A valve can be bent so little that it would not appear to not be seating if you measured the valve stems yet it would not seat properly and cause real problems with the engine running.

If you wanted to make a prelim check and keep costs down as much as possible prior to replacing the belt, I would suggest a leakdown test using compressed air rather than spinning the engine to build up pressure. This would give you the best proof of no leaks. This would take an hour or two of labor. Unless yo have one of the cars (like my daughters that calls for a bunch of hours to R and R the timing belt and several manufacture specific tools and LOTS of frustration) it wouls imply be cheaper to replace the belt and hope for the best.

 

I think I understand. Remove the timing belt cover, rotate the camshaft until both valves are closed for that cylinder, pressurize that cylinder with air at the sparkplug opening, then watch guage for pressure drop.
Then do the same to the other cylinders.

The flipside is that it might be quicker to put on a new timing belt and crank it over.

Right? Thanks.

 

you got it now.

Caution must be taken so you do not stick a valve into a piston while doing this though. That would be a bear, no damage until you manually rotate the engine and cram a valve into a piston.