I'm getting tired of working on Jaguars but I have no other choice. I've got a 2001 Jaguar S type 3.0 v6. A few months ago, my head gasket blew and I've started to work on it after a while (college got me super busy). I marked everything that I took out and I've managed to put in a new pair of head gaskets. After a few days of opening everything up and closing everything, the engine was finally back in one piece. I put all the corresponding electronic connectors back, connected the battery and turned on the ignition, but all I heard was a starter going tick tick tick and that was it. After a further inspection, whenever I turned on the ignition, the crank pulley would just go back and forth in a clockwise manner. I'm suspecting that I may have dropped a screw while I was working on putting in the head gasket or the crank has somehow seized up on me. What should I do? I'm literally stumped and I'm about to call up a junk yard for it.

 

Is the battery fully charged?

 

Two quick thoughts:

The back and forth motion could be caused by a weak battery. If partially discharged, the battery may not have enough oomph to fully overcome compression. As a piston rises on the compression stroke, the starter has to work harder to keep turning the crankshaft. With a weak battery, the starter can stall and if the piston hasn't reached TDC, compression will push the piston back down and briefly turn the crankshaft backwards. Make sure the battery is fully charged before doing anything else.

If still worried about internal binding of the engine, use a socket and breaker bar on the crankshaft pulley nut. See if you can manually rotate the crankshaft. If the required force seems excessive, remove the spark plugs so you're not fighting compression.

 

 

You are not supposed to turn the engine backwards.
So with no plugs you cannot rotate the engine by hand?
Did you have the engine locking tool in place when setting the valve timing? It's not set at TDC.

 

 

I expect that's the problem then your valve timing is probably off.