2001 Sebring 4dr engine knocking

Engine knocks during idle and while driving at low rpm it makes a high pitch sound and the car hasnt been taken care of well.

Mechanic says Engine replacement and he said it will lock up?

What should i do and is this true

PLEASE HELP

i got this off the net: http://encyclopedia.thefreedictionary.com/Engine%20knock

Knocking (also called pinking or pinging) in internal combustion engines An internal combustion engine or piston internal combustion engine is any engine that operates by burning its fuel inside the engine. This can be contrasted with external combustion engines such as steam engines and Stirling engines, which burn their fuel outside the engine. Jet engines and gas turbines use internal combustion, but the term 'internal combustion engine' normally refers to engines in which combustion is intermittent and there exists reciprocating machinery.
Occurs when fuel Petrol (in the U.S. and Canada, gasoline) is a petroleum liquid mixture consisting primarily of hydrocarbons used as fuel in internal combustion engines. The term gasoline is primarily used by the general public in English-speaking North America to refer to such a mixture and is also the common usage within the oil industry, even within companies that are not American. Often the term Mogas (short for Motor Gasoline, for use in cars) is used: to distinguish from Avgas, used in light aircraft. The public in most of the rest of the English-speaking world use the term petrol for such car-fuel, and other terms for other fuels, from the generic fuel itself to more specific names such as kerosene for aircraft.
In the cylinder is ignited by the firing of the spark plug A spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed aerosol gasoline by means of an electric spark. Spark plugs have an insulated wire which is connected with a induction coil or magneto circuit on the outside, and forms, with another terminal on the base of the plug, a spark gap inside the cylinder.

Spark plugs are typically designed to have a variable spark gap. The spark gap may be adjusted by the technician installing the spark plug. A spark plug gap gauge is used to set the gap. The simplest gauges are a collection of keys of various thicknesses which match the desired gaps and the gap is adjusted until the key fits snugly.
but burns too quickly, combusting completely before the optimum moment during the compression phase of the four-stroke cycle

The four-stroke cycle of an internal combustion engine is the cycle most commonly used for automotive and industrial purposes today (cars and trucks, generators, etc). It was invented by Nikolaus Otto in 1876, and is also called the Otto cycle. The cycle is characterized by four strokes, or straight movements in a single direction, of a piston inside a cylinder:

1. intake (induction) stroke
2. compression stroke
3. power (ignition) stroke
4. exhaust stroke

The resulting shockwave collides with the rising piston, creating a characteristic metallic "pinging" sound. The fuel is normally ignited slightly before the point of maximum compression to allow a small time for the flame front of the burning fuel to expand throughout the mixture, so that maximum pressure occurs at the point of maximum compression. It is only when this flame front arrives too early, for whatever reason, that the knocking effect occurs. If allowed to persist, knocking can cause vibration and damage to engine parts.

You could be getting pre-detonation, like the post before mine explains. However, your mechanic could be right. Your mechanic seems to think that you have a case of rod knock. Inside your engine you have the pistons which are connected to the crank shaft with connecting rods. There are bearings on these connecting rods. When there is room between the bearing and the crankshaft then you get what is called rod knock. The sound you could be hearing is the play between the connecting rod and the crankshaft. This causes the rotating assembly to be unbalanced and at higher engine speeds can cause the affected connecting rod to snap and send a piston through the wall of your engine.

I honestly can't tell you which you have unless I was to listen to the sound in person. Rod knock is usually cause by not changing your oil as frequently as you should. If you do have rod knock you don't need a new engine, you just need to have the engine rebuilt and new bearings installed.

My suggestion would be to get more than one opinion on what the sound is. The best way to find out if it is rod knock is to drop the oil pan and try to move the connecting rods. If any of them have excessive play, then you need a rebuild.

My Sister has this in her 2000 Sebring. Is this common?? What is suggested?

Fly Guy-- Personally, I would suggest to sell it and buy something different. My personal choice would be honda/toyota.
From what I've seen these sebrings aren't great in the reliablilty/longitivity area, although they do look good.