Has anybody even heard of this happening. It happened to me and I bent pretty much all of the valves. Still wondering why it happened!!!

 

I have not heard of this one.
Where is the bolt located exactly?

 

The bolt is in the center of the crankshaft drive gear. I have yet to hear of anyone else who has ever seen this happen. I am trying to figure out what caused it to break.

 

I am pretty sure that is going to be a fairly rare occurance. You may be looking at this in the wrong direction.

You are assuming that the bolt sheared causing you to lose timing and smash up your valves. It is reasonable to think that something else caused you to lose timing and the bolt shearing was a secondary result. For example, you could have snapped your timing belt or the belt could have skipped a tooth due to a tensioner failure. This will cause the cylinder to smash into the valves and bend them up. If a small piece of something breaks off during this process and lodges itself between the cylinder and the cylinder wall, it could seize up the cylinder. Since the engine is running and you have this catastrophic event, you can get a sudden very high force load as the cylinder seizes which is transmitted to the crankshaft and shears off the bolt.

There are other possibilities as well, but you won't know until you dig into the engine. Anyway, all I am saying is make sure you look around for other problems. The sheared bolt may not have been the origin of your problems.

 

I bought this car with some work done to it and I am trying to correct some things that may have been done wrong. I was told the engine was a 2001 but the head has a ATW code which I believe is a 2000 code. I am taking the head off this weekend I hope to have it repaired. Any suggestions on where to send it? Do you know where to find the engine code on the block? I notice the timing belt tensioner damper is broken which could have been the reason for the broken bolt but I am still not sure, only guessing. The bottom end seems to spin smoothly so it seems like it may not have been anything wrong there but I will look into a broken ring or something of that magnitude.

Thanks for any help.

 

not uncommon at all ( bad job done before hand and bolt not torqued down ) poor mechanical experience to blame but if you can find the garage that did it and it was done in less than 1 year then they have to fix it free because all work carries a 1 year warranty ( at least it does in the UK )

 

Hey Dave,
I would like to know if the correct head is on the car. The head is ATW how would I find out if it is the correct head for the car? Any Ideas?
Car is in the US and the work was done by a shady tree mehcanic.

David