Rebuilt Engines

My '94 Maxima is getting pretty old so I have two options:

a) buy a new car

b) buy a rebuilt engine

I want to know what a rebuilt engine is and the advantages/disadvantages of it.

Does a rebuilt engine restart the miles on your car to 0? Any information about rebuilt engines would be nice.

This really depends on what kind of money you want to drop into your maxima. A good engine will cost you a pretty penny ($1,000 - $3,000). Do you really want to spend that much for a rebuilt engine and possibly more if you get a different engine type and having to buy a new transmission also?
There really isn't any advantages to having a rebuilt egine since it is just like a regaulr engine just fixed what needed to be fixed.
But there is a couple disadvantages to having a rebuilt engine. Namely you don't know how the engine was run in the past and depending on how many miles are on the engine it might be ending it's engine life soon.
To your last question, No putting an new engine into your car doesn't reset the odometer to 0 because the mileage reflects the whole car like the body, the axles and everything else has been there for X amount of miles.

Hm. So I should just go and purchase another used car then?

If it is just a car just to get from point A to point B, that would probably be the best thing because depending on the mileage on the car if the engine is about to go or went probably alot of other things are ready to cause you hell soon and that would mean putting more money into a car that is only worth about $2,500. I would sell it (check kbb.com for good private sales pricing) and you can get another good car for about $3,000 in the newspaper. I just can't see spending upwards of $3,000 into a car that isn't even worth that much and having it run for maybe another 50k miles and completely dieing on you.

Well, a little bit on rebuilt engines. Engines from the factory are cast in raw form and then machined to their final specs. When you rebuild an engine, it is just machined again to a larger specification and different parts are used to fit the new parameters. So, depending on how good the machine work is, a rebuilt engine can be worse, as good as, or better than an original assembly. Typically they are somewhere between "worse" and "as good as."

Do some research and find some prices. One of the best engine rebuilders I've ever experienced is Jasper Engines. Some may disagree, but I was impressed with the facility.

There is a balance to be weighed here. There is the "if it isn't broke don't fix it" idea, but then there is the other side of the coin. Right now, your car has nothing wrong with it which means you can get a fair market value for it. If you keep driving it and it has a massive failure, you suddenly have a $100 car.

Is there anything particularly wrong with it? Does it still run well and provide good transport, or is it a constant money pit?

Nothing wrong with it really. My friend's told me to look into another engine. Although whenever it gets fairly cold, my car won't start up without a jumper.

Nothing wrong with it really. My friend's told me to look into another engine. Although whenever it gets fairly cold, my car won't start up without a jumper.
Don't rebuild an engine unless it has obvious problems, such as burning oil, low compression, poor power and fuel economy AND these problems can be specifically traced to worn engine components.

There are tests that can help determine the condition of your engine:
1. Compression test
2. Cylinder leak down test.
3. Engine oil contaminent test

Sometimes, a part of an engine can be worn, which can be replaced without rebuilding the entire thing. It is common for some engines to wear out the cylinder head components first, such as valve seats, guides, and valve gear, such as camshafts and rocker arms.
Sometimes a rebuild cylinder head can be installed, which can restore the engine performance at a fraction of the price of a new engine.

The key point here is to do some diagnosis. Consider paying a mechanic to do a thorough inspection and test of the car first. Often, hard starting is caused by something other than a worn engine, such as an ignition or fuel- related problem. Please note that a rebuilt engine on its own will NOT fix electrical or fuel delivery issues.

Good advice from MagicRat. A leakdown test would provide the most accurate and detailed picture of your engines condition and where any problems may lie, as long as the shop administering it knows what they are doing. They aren't as common as compression tests however, and cost more to have performed. They are still far cheaper than a complete rebuild though.