Rattling Sound Coming from middle of engine! Sounds like DIESEL,Advice needed please!

Hey guys, I own a 1991 Ford T-bird reg. model (not an SC or LX) V6 engine, 3.8l.

And I had bought this car for $1,000, mileage 145,000

I know thats alot of heavy mileage but I've heard that these cars run over 250,000 if they are well maintained...

Well anyway what my problem is...

Once I crank up my engine I can hear this RATTLING sound, Like a DIESEL engine. It sounds like the drivebelt not being tensioned, but one mechanic said I need a new alternator and its going soon. Another one thinks its my water pump. I just want to know everybody's opinion on this , If they have been through this before and know what that sound is.

Thank you...

Take a LONG screwdriver and CAREFULLY touch it to the alternator body (not near the wires) and put the handle on your ear. This acts like a stethoscope so you can hear where the noise is coming from. Move it to different places on the engine (waterpump, etc) until you find where the noise is coming from. Be very careful of rotating belts, pulleys and wiring when doing this!

Does it go away shortly after start up or does it continue to be present when the engine is running?

my car made that noise when I overheated it. It happened to me twice. does the rattling increase with RPMs?

A spun bearing can cause the same sound. Is it more of a tick, a tap, a knock, a rattle, etc?

It continues throughout driving. =/

Its definetly a Constant RATTLE, like a DIESEL engine! from the Front Middle end of the engine. I also noticed when I put the car in Neutral the rattling goes away in the engine.

It may be a long shot but check the PCV valve. Those can make some interesting sounds.

Is your oil pressure normal? Sounds like under a "load" condition is when it happens. Could be a bearing or a lifter/valve issue. Pull your valve covers and look/listen for anything unusual

no , it continues throughout driving....its a pretty loud rattle

no it stays the same. its definetly coming from around the alternator though.

it continues when the engine is running. =)

okay i will thanks for the advice