I just purchased a used 2002 Monte Carlo SS, 3.8. I've had it for a little over 2 weeks, and only put on 27 miles. Now, it is making a scraping noise in the lower portion of the engine. The mechanic is telling me there is a problem with the crankshaft. I have tried searching the net to verify this, but there isn't anything on symptoms of a bad crankshaft. Can anyone help???

 

ARE YOU GETTING A CEL? (Check Engine Light)

It almost sounds like someone bottomed out the car and the crank is scrapeing the bottom of the pan? (Its a guess)
A video of the sound would also help to make a diagnosis....
But I can honestly say....
I have never heard of that on a 3800.

 

It didn't throw any codes. I went to the mechanic to get some other minor repairs done. This is a mechanic I trust so I believe he wouldn't do me wrong. I'll take a look at the bottom of the car today though, that does sound like a possibility. Thank you.

 

If you need a crankshaft just get a new shortblock, IMO.

 

A grinding or low pitched growling sound is indicative of worn main bearings. If you trust the mechanic then nighthawkjcb's suggestion about getting a short block assembly would be the most cost efficient way to do it. By the time you added up the cost of parts and machining to repair your engine you'd be deeper into your pocket. If you want to freshen up the top end also then go with a long block assembly.

The only other option that would be less expensive would be a used engine from a wrecking yard.

 

I really appreciate everyone's comments. We took it back to the dealership via tow truck. When they opened it up, it turned out to be a thrown rod. Haven't got word back from the dealership mechanic yet as to why, but the consensus so far is that my mechanic let some coolant get into the oil when they changed the intake gaskets and plenum. Guess I need a new mechanic!