NatedoggAZ

Hello,

I drove my car home with no issues last night and no engine sounds at all. This morning when I started the engine, there was a horrible sound! It sounded like a rock or a marble bouncing and tumbling around inside my engine! I turned it off real quick, and then started it again with the same sound present. I let it run for a few seconds (probably no more than 30) when I opened the hood to see if anything was visibly wrong – but there wasn’t. I didn’t have much time to look into it because I had to go to work. I am not driving it now, it is parked until I figure out what the problem is.

Does anyone POSSIBLY have any reasoning for the cause of the sound? It is hard to tell where the sound was coming from – it sounded like it was coming from all over the engine.
Should I pull off the belt and run it to see if the noise is still there? I guess that would eliminate quite a few things?

I really appreciate any feedback or suggestions on this ASAP.

1998; 4.6L; 150k

Thank you very much!

ND

JC316

Pull the belt, make sure that it isn't an accessory. If it's still doing it, there are a number of things in can be. Timing tensioner, collapsed lifter, spun bearing, bad oil pump, etc. My money is actually on either the alternator bearing or the A/C compressor.

NatedoggAZ

Thank you for your suggestions and feedback! I HOPE you are right, that would be an easy fix. I just dont have the $$$ to spend on tearing open the engine or any kind of rebuild on this car...

T.Richardson

Could be the timing belt?

NatedoggAZ

OK - so I started the engine yesterday and the sound was still there - but not as bad.

I ran for a few seconds and turned it off.
I removed the belt and started it again - this time there was no sound!
So the sound is not coming from inside the engine....

Where could it be coming from? Did not sound like alternator.
Could it be the water pump bearings or something? That has a pully in front...

Thank you!

Nathan

NatedoggAZ

...I also put the belt back on, restarted the engine and the sound went away after a little while. I let it run for about 5 minutes and the sound was totally gone at idle RPMs....this one has me stumped. If it is the water pump, seems easy to change out hopefully since it is right up front..?

MZR160

Power Steering Pump, Belt Tensioner or Idler pulley. With Great Care you can use a long screwdriver like a stethoscope to possible determine where the noise is coming from.

Rokgtar

The 4.6 v8 has no timing belt, just dual chains with tensioners...

NatedoggAZ

Argh - I have to wait until the sound comes back now... Just went out and started it again and the sound was still not there. If it happens to be the water pump, is it bad to drive it with it making that noise? Like if I drive it to work tomorrow with no issues, and it starts making noises again on my way home....will it break anything?

JC316

I highly doubt it's the water pump. Easy way to check is to see if there is play in the impeller shaft. Just grab the pulley and try to move it around, it should be solid. Usually if it's the pump, it will be leaking.