I was going to change my Timing belt next week while I was on holidays since it has 103,000 km (64,000 miles) on the belt. The engine has 400,000 km (250,000 miles) on it. I guess I waited to long. I pulled out to pass someone on the highway and the timing belt blew. I got it stopped in a couple hundred yards. I've got the front of the engine apart to replace it but ran into another problem I think.
Without the timing belt on, and both cams on their timing marks, I can spin the crankshaft pulley easily by hand. There is almost no compression it seems. I checked with the local dealer and they say the valves don't get damaged when the timing belt goes. If it was a head gasket problem, I would have thought there would be good compression in at least some of the cylinders.
I guess my first question am I right in assuming I shouldn't be able to spin the crank by hand with the timing belt off?
If there is a problem, what could be the cause? If a head gasket blew, some of the cylinders should still be OK shouldn't they? Since the timing belt runs the oil pump, could I have damaged the cylinders in that short of time after the belt blew?
Thanks