Machines break down and moving parts wear out, that’s just a fact of life. Engines are no different and sometimes an overhaul is needed to restore the engine to optimum performance.
So what does an engine overhaul entail?
With so many moving components, there will be inevitable wear and tear that goes on inside the engine. An overhaul means taking the engine out of the car, and taking it apart to get to the insides, particularly the pistons, piston rings, rods and bearings, which all need to be replaced with new parts. The engine is like an air pump, and when the piston rings and bearings are worn out, air doesn’t get pumped as efficiently as it did before.
So how do you know if your car needs an overhaul? Excessive white smoke coming from the exhaust is an almost sure sign the engine needs it. Another sign is that the engine doesn’t idle smoothly and seems like its sputtering, often on high mileage (200,000km +) vehicles.
Our standard charge is P20,000 to take out the engine, take it apart, and put it back into the vehicle. Parts of course are extra.
Here’s a rough typical estimate for an overhaul job:
Overhauling gasket set – P9,000 to P20,000
Once you take apart the engine, all the old rubber gaskets, seals, o-rings can’t be reused and thrown away due to age and deformity.
Piston rings – P900 to P1500/pc
You will need 4 of these on a four cylinder engine (no duh), assuming that the cylinder bore is still within specifications, and that the pistons themselves don need to be replaced with bigger ones.
Pistons – P2,500 to P4,000/pc
Sometimes, the wear on the cylinder is too big already and the piston to bore clearance is way out of spec. A bigger piston is needed.
Cylinder liner – P1,500 to 3,500/pc
If no bigger piston is available, replacing the cylinder liner with a smaller one and then machining out to the correct spec is an option.
Rod and main bearings – P4,500 to P7,500/set
These bear the brunt of the rotating force in the crankshaft so they need to be replaced.
Machine shop – P5,000 to P25,000 per engine
More often than not, the engine is sent to specialist machine shop to be checked for tolerances and perform needed work on the cylinder bores and cylinder heads. The reason for the wide range of prices is because each engine is different and for sure will require different levels of work, from something as a simple honing the cylinder bore to milling out and pressing in new cylinder liners.
An overhaul can also be called an engine rebuild and for the performance oriented person, it involves replacing the stock internals with something significantly stronger like forged pistons and connecting rods to withstand higher levels of power. With the exception of the component costs, machine shop and labor costs are pretty much the same. Follow this article on auto repair and check what options are available if you don't have money for car repair.