Engine 00 Prizm troubles

00 Prizm troubles

Ok, I have a few questions for you guys.
Basically, my troubles started with my 00 Prizm when it wouldn't start. I had to have it towed, and it was determined the timing chain broke. put a new timing kit and did some other small work, but it won't start still.
The mechanic has said that he is convinced a valve was 'sucked up' and is stuck in the head, and it needs a valve job, or a new engine. My first question is if there is a stuck valve, wouldn't a simple comression test show that? rather than just assuming thats what the problem is. Second, he said that if i am going to do new valves and stuff, I'll need to do bottom end as well, otherwise there will be too much stress on the bottom end and it will fail within a few thousand miles. Does this make any sense to you guys? I just don't want to spend a pile of money on this car and have it still not running. I'd like to get the car running and sell it, since its still a nice car, but I don't want to lose a bunch of money on it. I'm just surprised that this much damage would have happened when the car wasn't even running it was trying to start, and its suppoed to be non interference.

Well if the timing chain broke while you were driving, its possible that the valve got stuck. But as far as rebuilding the bottom end of the engine, I don't think you need to do that. When you rebuild the top end it should have the stock compression, and that is what you were running before, so it shouldn't damage it.

Would you think it would be unlikely for that to happen if the car wasn't actually driving? I was just trying to start it when this all happened, it was just starting to crank over, made a bang, then quit. I'm also curious, even if a valve were bent or stuck, wouldn't it still turn over and run or would that completely stop it from starting. I'm not an expert, but if a valve is stuck is it possible that maybe a stuck valve could stop the cam from turning thus not allow it to start. I have seen a site somewhere selling a rebuilt ready to install head for 350 shipped. I'm think if I installed this it should fire correct? The real problem is I don't know exactly whats wrong, and I don't want to blow all sorts of money trying to fix what I don't know is broke. Am I correct in thinking a compression test would identify a valve problem

I guess it could be a stuck valve, but I'm no expert either

Here's another question, my father in law for some reason thinks it could be a broken crankshaft, but that sounded unlikely to me, any thoughts?

Unlikely, the 1ZZFE crankshaft is pretty tough. Even if you purposely hydrolock the engine - you'd bend a rod before you damage the crank.

If the valve is jammed into its seat and made a perfect seal - a compression test will not really show it. But if the valve is jammed in such a way and letting air through - you would definitely see this in a compression test. I'd do one anyway to make sure all is well. Won't be the ideal test - as you generally need to warm the engine up> but you should be able to hold some pressure - if in doubt, a little motor oil in the cylinder can help make the rings seal up against the cylinder walls and not affect the valves as much.

You can take the valvecover off and take a peek - see if something is obviously bent or damaged - as this is a pretty easy job. If you are careful, you could even reuse the old gasket, though I'd recommend against it.

Bottom end work is only needed if the valve dropped and got chewed up by the piston. Then, you need to double check that the cylinder is quare and within spec. and that no other problem is suspected. If he wants to double check the crank - just pull the oil pan and have a look see. Pulling the oil pan and valvecover + compression test should get you 90% of the information you need - for determining if you need to rebuild or swap.

thanks fish, thats kinda what i thought, I'm thinking there couldn't have been a massive amount of damage, it wasn't even running. I was just trying to start it. I found a good price on completely rebuilt ready to install heads online, so I might just have him pull the head and make sure he doesn't see any other major damage and we'll drop another head on it and hopefully get it running again. I should be able to get the rebuilt head to my door for 350, then its just a matter of a crapload of gaskets and waiting for him to finish her up.

One more question, Several people have mentioned that in their opinion, even with a stuck valve the car would start, but might not stay running or might be real rough, but they thought it should start, where this car won't start, what do you think?

If it was just that one valve (other cylinders are fine) and depending on how it broke - I would assume that it should check fire at least once. Kind of like disconnecting the sparkplug on one cylinder - it will still kind of run, but not very well or for long.

Any weird noises when you crank it over? I'm hoping the valve didn't jam in such a way that caused the cam to lock up on you. That could mean a broken timing chain or damaged teeth. In some really bizarre cases - maybe a broken camshaft - but that is as likely as a broken crank.

I'm also assuming that the mechanic has checked the basics - fuel and fire. Engine cranks over OK just doesn't catch? Should pull the plugs and see if they are "wet" with gas. Injectors working? Listen for that telltale ticking noise with a stethoscope or noid like on injector harness. Ignition hot? Check for spark - old school works OK to just test. Take an old plug - jam it into the coil on plug unit - set the ground strap of the plug to a good chassis ground, crank it - should see a spark. I'm also assuming that the timing is OK - as it is real easy to get timing off by 180 degrees, at least that was my problem back in the day.

Otherwise - it could be as simple as a missed connector or a bad sensor (crank or camshaft position sensor) that tells the ECM when to fire. Could be something with the VVT-i solenoid or assembly. There is a plug that you can pull that will disable the VVT-i system - at least it should do something different. At the very least trip a new CEL, so that you see that the ECM is alive. Good Luck.

Timing was screwed up, that I knew. Harmonic Balancer broke completely off, cam sprockets were shredded, guide rails were pretty hosed, etc. I bought a full timing kit and had it installed, now it cranks but won't start. Mechanic says he hears something in the head, but I haven't heard it myself. I'll have to try to get over there this evening after work. If it turns out to be a problem in the head, like I said, i can get a full ready to install head for 350, but I want to be sure thats what it is first obviously. I'll have him check the basics and if there's fuel and spark, then I'll pull the head and put a new one on i guess.

Ok, well, here's the update, although its not a good one. Engine is shot, or at least need to be bored, rebuilt all that good stuff. I don't really want to spend the money to buy a new engine either, cause everything I've found so far has been pretty pricey for an engine. So unless i find a great deal on a running engine, the Prizm will go up for sale as is, and if there are no takers, she goes to the scrap heap