5.0 MPI Possible big problems

I was just getting the boat up to speed yesterday and heard a pop... it acted like it came out of gear (alpha drive 2004). I immediately let off the gas and came to a stop. The motor was still running fine, i tried to put it back in gear and nothing happened. The motor was still running fine and would rev up with no issues. I jumped in the water and checked the outdrive it was fine didn't hit anything in the water. Started the boat still ran fine wouldn't go into gear. 20 min later the boat would not stay running and was making a bad clunking sound. It will not rev up and it backfires and dies if you try to rev it up. Where should I begin looking to find my problem? Thanks

Re: 5.0 MPI Possible big problems

ouch.... you might as well check the oil for water first. then pull the plugs and check for water in the cylinders as well as any physical damage to the plugs.
If everything checks out then move on to a compression test. if it doesn't check out you might as well make plans on pulling the motor and tearing it down.

It almost sounds like you either spun your coupler, or snapped the vertical driveshaft in the drive. Either 1 would cause the water pump not to work. Then after your running of the engine for 20 minutes seriously overheated it.
You say there was no physical damage to the prop/drive. Did you happen to be jumping this thing in and out of the water?

Re: 5.0 MPI Possible big problems

I`m with Jason, check the engine oil and fuel sep. Check the oil level and condition in the drive. Blown coupler or shaft above the water pump and you`ll overheat. Pull the drive to isolate the noise