Hyundai Repair: Hyundai Santa fe 3.5, camshaft sprockets, hyundai santa fe

Question
QUESTION: I just did a timing belt on a 3.5.  The back cam slipped and might of hit the piston.  Will it bend the valves when this happens? Could I have gotten any of the cams 180 out?    The cam timing is right on but the car will not start.

ANSWER: This would not have bent the valves as long as there was no attempt to start the engine.  If there was an attempt to start the engine, then all bets are off in regard to whether the pistons hit (and bent or broke) the valves.  Even if this occurred, as long as the engine cranks, it should still start if the camshafts are properly timed; the engine will still run on three cylinders.  If the camshaft sprockets are lined up properly, they cannot be 180 degrees out.

If it's not starting, check the following:
-- Is everything plugged in properly?
-- Did the crankshaft sprocket assembly come apart?  This can occur if the sprocket sticks to the pulley.  If so, the engine probably isn't timed right.
-- Was the crank sensor damaged during disassembly?  This can occur if the sprocket sticks to the pulley.
-- Was the crank sensor removed?  If so, was it reinstalled properly?


---------- FOLLOW-UP ----------

QUESTION: HT,
The crank sporcket tried to come off with the pully.  Is there a way to tell if the crank sensor has been damaged?  What does the engine sound like tring to strat with a bad CPS?  Can the plate that triggers the CPS slip postion? Thanks for all your help.
Best regards,
Peter

Answer
You'll need to disassemble things so you can take the sensor and sprocket off and inspect them.  When the sprocket sticks to the pulley, the plate catches on the sensor, and it typically pulls the plate loose and cracks the sensor.  This can cause the plate to come loose from the locating dowels and slip position.  Expect that you'll need to replace the crank sprocket assembly, and if the sensor is cracked, the sensor too.  

Unfortunately, this may not be the end of your troubles.  I saw a job where a technician was attempting to replace the crankshaft pulley, this situation occurred, the plate slipped, and he didn't realize it.  He knew he had a potential timing belt problem but didn't realize the plate had slipped, and retimed the engine to the incorrect plate position.  When he started the engine, he bent the valves.  As I recall, it needed one cylinder head and all valves.

If the cranks sensor itself is bad, the engine will sound normal when cranking (speed and tone) but will not start.