Hello guys. I have been searching online for hours now and have not found an answer to my simple question so I don't know if this is something that I am just stupidly overlooking or what but here is my problem:

I have a 2003 Civic LX. It has always been extremely well maintained until the last 25k when I thought I would be scrapping it soon so I ignored the need to change the timing belt. It turns out that I need to repair it and my timing belt just snapped. I am at the step of repair now where I just need to line everything up and put on the new belt BUT I cannot turn the top pulley (attached to the head) which is out of alignment. I know where TDC is and all of that stuff but I just cannot physically turn the top pulley no matter how much I crank on it by hand. The bottom one turns but the top one just doesn't. I don't know if there is some simple solution that I am somehow missing but I can't figure out how to make it turn. I saw one video where someone unbolted everything from the rod so that it could move but that seems like it would defeat the purpose of turning the shaft if none of the components move with it.

Any help would be EXTREMELY appreciated.

 

you should just pull the camshaft to ensure no damage before turning the crank

 

Did you inspect the cylinder head after the belt broke? You need to be sure no valves made contact with pistons and bent - which is likely to happen if the belt breaks while the car is running.
Are you rotating the crank a full 360 degree turn? And you can’t rotate the camshaft? If that's the case there is definitely something wrong with your cylinder head and it needs to be checked for valve damage.

If you know your valves are fine. If the crank is at 1/2 TDC/BDC, where all pistons are at half stroke. Then the camshaft should be able to be rotated without interference.

 

+utn

I have not removed the cylinder head yet because I want to put the new belt on and compression test the cylinders to test for damage. I can rotate the bottom pulley 360 degrees but the top one will not move a millimeter in either direction.

 

I would assume at that point that some of the valves made contact with pistons and are bent.
To diagnose by taking out minimal parts - you could try taking out spark plugs and looking down the plug holes and trying to see if there are any marks on the tops of the pistons from hitting valves. A borescope would be ideal if you have access to one.

Maybe other people have other tips on how to confirm the issue without removing the head.
Taking out the camshaft is not overly difficult and would clearly show you which valve springs do not retract to fully closed (valve is bent). Or you might be 'lucky' by taking off the valve/rocker/cam cover and see if any of the rockers are very loose because the spring underneath is compressed without the rocker compressing them.

Or you could even try to remove the valve cover and with a wooden dowel press down each valve spring manually (it will take a bit of force/body weight) and see if any of them are incompressible.

 

I would remove the valve cover and look for visual damage, like valves stuck down. If there are valves that are stuck down, you will likely have a lot of up and down play on that rocker arm. Also, if your valves are bent, you are likely better off getting a used cylinder head than fixing that one, since a machine shop should really install, grind and test the new valves, which is quite pricey. If the pistons are damaged, you may want to look into just replacing the engine. Replacing the engine on these cars is quite easy if you have the right tools, and may be cheaper than replacing pistons, trying to figure out what else may have been damaged, worrying about clearances, finding a replacement head or repairing the damaged one, and all the other joys that come with repairing damaged engines. Anyways, good luck with your car!