Never a dull moment... (or a good, exciting one.)

[Memphetic]

Was driving at a leisurely pace yesterday to get the low-load (-14 to 0 psi range) tuned on the AEM in my car. Everything was going well and starting to smooth out nicely, and I was decelerating using the engine down a hill when suddenly there was a disgusting sound from the engine bay. The car stalled. The sound didn't last very long, so I wasn't too sure of what had happened. I attempted to start the car again, only to hear the starter grind against the flywheel. I then tried pop starting it, because maybe the starter had locked up; same sound.

Pulled the starter today... a couple of teeth on the starter are chipped, but it operates properly. No damage on the flywheel. I then rotated the crank assembly by hand with a breaker bar at the crank pulley - the crankshaft rotates, but the cams don't, and you can feel it skipping the teeth on the belt. Place your bets on what's fucked.

[stealthee]

Obviously the cams were spinning properly before, so that has to leave out the cam caps bieng the right ones and being in proper location.

[Memphetic]

Removed lower intake plenum; intake valves aren't bent. I suppose the next step would be to remove the timing belt, place the crankshaft at TDC, and attempt to move all of the camshafts by hand. Or perhaps remove the valve covers to see if perhaps a rocker fell off and jammed one?

[RealMcCoy]

You can't tell if the valves are bent just by looking at the back of them... You need to do a leakdown test. Looking at the back of them will only tell you if they are REALLY bent...

Put the crank 4 teeth back from TDC to turn the cams. That puts all pistons as far from the valves as they're going to get. If you turn the cams at TDC you'll hit #1 and #4.

[JGreenwood238]

Put the crank 4 teeth back from TDC to turn the cams. That puts all pistons as far from the valves as they're going to get. If you turn the cams at TDC you'll hit #1 and #4.

I don't mean to go off topic, but that's very helpful info. I was wondering where the safest place to leave the crank would be when I replaced my lifters, I ended up just leaving it at TDC and tried to be as careful as possible when I reinstalled the cams. Thanks though, I'm going to keep that in mind for next time.

[RealMcCoy]

I don't mean to go off topic, but that's very helpful info. I was wondering where the safest place to leave the crank would be when I replaced my lifters, I ended up just leaving it at TDC and tried to be as careful as possible when I reinstalled the cams. Thanks though, I'm going to keep that in mind for next time.

It's just math... There's 24 teeth on the crank gear, so each tooth is 15 crankshaft degrees. There are two pistons at TDC every 120 degrees. If you turn the crank 60 degrees, you'll have all the pistons as far from TDC as they're going to get.

[Memphetic]

Even if they were bent, it wouldn't PREVENT the cams from turning.... that's the weird part...

[stealthee]

But if they bent and threw rockers...

[CoopKill]

Froze water pump, or pulley. Is exactly what mine did at 50 mph. Thought I f-d all the valves, but the crank spun in the belt. Only slightly bent 2 valves, not enough to prevent a seal. Bearing from pulleys everywhere as when one froze the rest were nuked. the belt welded to the water pump, and prevented the cams from turning.

[RealMcCoy]

I would just proceede to check out why the belt spit... Just because the cams aren't turning doesn't mean there's anything wrong up top. If the belt has a bunch of teeth torn off around the crank gear, or if the belt tension is gone, it's not going to turn the cams...

It's extremely rare to spit a belt on one of these cars and NOT bend valves... If you did, my advice is buy a lottery ticket.