What is an Engine Rebuild?

November 17th, 2015 by


Car Engine Repair Parts


It’s one of the toughest, dirtiest, and most intimidating jobs in car engine repair – lifting an 800-pound chunk of metal out of a hood, figuring out what is wrong with it, and making it work right again. And, if you own a car, you likely may have to have it done.

This, of course, is the infamous engine rebuild.

If you’re looking for a car engine repair shops, it’s a good idea to know what you’re getting into before you see a professional mechanic. 

There are multiple reasons why you might find your engine needs rebuilding, and whatever they may be it is important to have the problem addressed immediately. Otherwise, a small, fixable problem like an oil leak or overheating can become permanent, irreversible damage.

For that reason, it’s good to familiarize yourself with the engine rebuild process. Whether you plan to bring your car to an experienced mechanic or you plan to tackle the task yourself, it’s helpful to know a few of the things that can go wrong with a standard engine, and what can be done to get everything back in working shape.

Car Engine Repair Parts


Why does my engine need to be rebuilt?

There are several reasons your engine might require repair. The most common signs that a rebuild may be in order are loud knocking or grinding noises emanating from under the hood. If it sounds like something is banging your engine with a wrench while you drive, it is very likely a loose rod or a piston is the culprit.

Difficulty starting could mean the cranking is extended which, when coupled with a lack of engine power or rough idling, could be a sign of lack of compression, probably the result of a crack or leak in the combustion chamber. A mechanic can run a compression test to diagnose lack of compression prior to rebuilding the engine, and so it is good practice testing before beginning work.

If it seems like your engine is using oil too quickly, it could be a sign of an oil leakage, which can greatly damage your engine. This could result from stuck oil control rings, worn valve guides, and other things, so it is important to isolate the problem prior to beginning work, if possible.

If you notice any or all of these symptoms in your engine, it is likely that you will indeed require an engine repair or rebuild.


Is repairing or rebuilding an engine even worthwhile?

Obviously, this is up to you and varies on a car by car, driver by driver basis. If your engine already has 300,000 miles and 25 years of driving experience, then it may not be worthwhile to go through a whole rebuild since the cost of the work may actually outweigh the value of the engine. Sometimes, however, this still may be less than the cost of buying a new car, and so for many drivers an engine rebuild is a cost-effective solution to major engine troubles.

However, if your car is under ten years old with only a few thousand miles, then it is very likely that an engine rebuild is the best and most wallet-friendly option, and the sooner it is done the greater the chance of avoiding further damage.

So what exactly goes into an engine rebuild?

Luckily, the process of an engine rebuild can be done in incremental steps, each involving succeedingly more labor for a greater amount of repair. In some cases the only repairs needed do not require the engine to be lifted out of the hood at all; other times, a routine light repair ends up revealing deeper problems that can lead to a more intensive rebuild. It’s best to start simply and look carefully to determine just how in-depth of a repair job your engine requires.

A mechanic will often start with a ring and valve job, a relatively simple procedure that does not require lifting the engine block from out of the hood. The mechanic inspects the head before removing and rebuilding it, removes the pistons and replaces their rings. He or she may also replace the rod bearings and re-hone and re-glaze the cylinder walls. Parts that still meet the manufacturer’s specifications are not replaced, and so the mechanic only fixes the parts most in need of replacement or repair.

If, however, the mechanic discovers further issues while the engine head is off, like excessively worn cylinders with loose pistons, then a full in-house engine rebuild may be in order.

At this point, the engine block has to be lifted out. The mechanic has to be able to reach the cylinders so that he or she can bore and hone them fully, making each properly fitted for a new piston. He or she should also replace several parts like the timing components, the rod and main bearing, the freeze plugs, and any other noticeably worn or damaged elements. The mechanic should also take care of any other needed repairs and deck the block, or square the engine block perpendicular to the cylinders In some cases, the mechanic may need to send parts to a specialist for specific machining and finishing before repairs can be completed.

In many cases, a mechanic will opt for an in-house repair, where parts are repaired and replaced bit by bit as need be. The other option is for a total rebuilt exchange, in which essentially all parts of the engine that can be replaced are, regardless of whether or not they were previously in working order. This is typically the most expensive and most thorough repair job available, but will almost surely get the job done.

hands on chevy engine

OK, so I rebuilt my engine. How long will it last me?

That’s hard to say, but hopefully for quite a while. If the rebuild job has been done correctly and has thoroughly addressed every problem, there is a good chance that with regular maintenance and care your new engine could last for the life of your car. However, if the causes behind your engine trouble have not been resolved, like a clogged radiator or simply bad maintenance habits, then it is very possible that the symptoms will return.

Many rebuilt engines come with a one-year warranty, but be aware that mechanics can tell after the fact if an engine has overheated or run out of oil, which can invalidate that warranty.

A newly rebuilt engine is a big undertaking, but when done properly it can seriously save your car from the scrapyard for years to come.

If you need car engine repair Albany, NY, ask your mechanic if a full engine rebuild is necessary for your car.