Chrysler Repair: Is my motor really locked up, diagnosing engine noises, engine rebuilder

Question
I have a 99 dodge intrepid 24 valve dohc we have only had it 2 months it has 88x miles on it it recently died and the oil light came on when we checked the oil it was empty so we put 2qts in it and drove it home the next mornin it fired up just fine no. Knock or oil light so my wife drove it to work it died on her and the oil light came oniy was knockin so she called a shop and had it towed they looked at it and first said the motor was blew but then latter said it was locked up and they wanted 2400 dollors for another motor i drove it home from the shop it is knockin lightly but it run and drives , i didint think a motor would drive if it was locke up?iy doesent sound locked up? It is knockin but do we really need a new motor? How long can we drive it like this? Is there a cheeper way ?what would i need to replace? This is our only vehikle

Answer
Hi Jason,
If it was 'locked up' then the starter motor wouldn't have been able to turn it over. The cause of the knock might be able to be suggested by a shop with experience in diagnosing engine noises.
So if you can get it to an engine rebuilder that person might be able to tell you what he thinks is specifically wrong with it. Once that is known you can get an idea of how much further it would go before it fails permanently and also how much it would cost to repair. That has to be diagnosed on the spot, not at a distance.
Roland