I just had my wife's car (92 Nissan stanza) in fr some repairs (fuel injectors, and valve cover gasket). After the repairs were completed, they road tested it, and evidently one of the timing chain guides broke. Now there is 0 compression in all four cylinders due to all the exhaust valves being bent.

I need some insight into just how this would happen (I don't know enough about engine timing mechanisms to understand exactly what happened0, and what other questions I need to ask. Is it possible that something happened during the previous repairs to help cause this? Was the engine pushed too hard? etc.

Thanks for any and all input.

 

Moved to Under the Hood

 

Theoretically - it would be impossible to bend all the exhaust valves since they dont open up at the same time - I dont know the firing order of the 92 Stanza - but worse case, 2 exh and 2 int valves are bent.

This car is quite prevalent in junk yards - if I were you, I'd just pick up a head and bolt it on. I'm fairly confident the block is just fine. You could also pull the head and drop in some new valves - and do a valve job - test the seats. But a remain head is fine.
Get the shop to pay for it

 

I reread your post - I thought the chain broke - it was the guide that broke. I suppose the crank kept turning the cams and all your vavles could be shot to hell. When you pull the head - run a bore gauge and check for scaring on the pistons and cylinder wall. You may also want to pull the pan and make sure there arent any shavings down there.

 

One incident could bend all the exhaust valves, if not during the exact same piston stroke. Say a redline downshift instead of upshift. More than one valve could be damaged before the engine decided to quit. Or if the timing slipped enough in an "interference" design then all the valves could get banged.

 

It doesn't sound like this was likely their fault, though it could have possibly been excited by abuse on their part. Regardless, it would have likely happened sooner or later and you will have a hard time getting them to warranty it or cover it as damage caused by them. Depends on how nice the shop wants to be to you.

I'd recommend a used head, provided the bottom end isn't damaged. Once the head is off they should be able to tell. I'd also try and get them to cut you a deal on the work since it happened on their time.

 

Thanks for the replies.

It look like I can replace the whole engine for about $1400 (labor included). Looks like this is what I'll do.

 

My wife had a '90 Stanza, and the timing chain guide broke on hers as well. This is fairly common on that engine. We were lucky - I recognized the noise immediately, and towed it to the dealer with no damage done. It is definitely an interference engine (bad things will happen if the chain breaks).