Starter won't turn engine
 

Hello
I have a 99 jimmy 4x4 with a V6. I have had problems getting it to run. I have a new battery and starter. But for some reason I can't diagnose why the starter hits and try's to turn the motor but can't. I can see the serpentine belt move slightly. Any suggestions would be great

Is the motor locked up? Can you turn it over with a socket on the crankshaft pulley? Remove all the spark plugs and try it again - it could be hydrolocked as well. Be careful don't break the bolt off in the crankshaft.

Thanks for the response. Yes I can turn the crank. I will try removing the spark plugs.

If you can turn the crankshaft with a socket then no need to pull spark plugs.

turn the headlights on. Do they go out when you try to crank the engine with the starter?

The motor was hydro locked. But it's a good thing I pulled the plugs. 4 out of 6 fell apart. I was told they were replaced by the previous owner.

Glad you have it figured out! Thanks for letting us know.