Today, almost every service station offers to pick up a ‘contract engine’ instead of overhauling the engine or even repairing the wear and tear on some components. The arguments are simple: faster, cheaper, warranty. Benefit? But in practice, the situation is quite different.
So, the syndromes are disappointing: smoke coming out of the chimney, no power, soot build up on the plugs, fuel and oil consumption “overstepping” all imaginable and unimaginable limits. Verdict of a mechanic: engine is dead. In confirmation of the words of the mechanic – low compression in cylinders and knocking when working “at idle”. It’s time for the engine to rest.
The decision will be offered at once: why to get hands dirty and spend the extra money, when it is possible to install a new engine quickly and technically? Well, how, new: used, but in good condition. Warranty! The engine is contract. Paperwork, stamps-signatures – everything is available.
The reason for such craving can be explained simply: it is financially attractive operation not only for a “victim” – a contract engine will cost cheaper than overhaul and the more so, overhaul – but also for service. In fact, with good luck, the car will occupy precious lift no more than two-three days, and a mechanical genius will not be needed for such work.
Absence of strong motor mechanics is the reason of mass enthusiasm for contract spare parts: it is impossible to find a good mechanic, and he will ask for his work many times more than a mechanic, languidly chewing biscuit on his salary. Simple arithmetic, the same as a bird in the hand. Just business.
The arguments “for”, which will bring the distressed car owner everywhere are approximately the same: the contract engine is cheaper, it is available, the engine is now legally a part numberless part, the work will take less time. From all aforesaid only the last is true: engine overhaul or, God forbid, complete overhaul takes very long time. In fact, a tired power unit is to be disassembled, defect, choose and find the necessary spare parts, repair the units to be restored, and only then assemble.
This “cheap” story is always a success! Nothing captivates the car enthusiast more than the opportunity to save money.
A really good contract engine, with low mileage will be expensive. Not much cheaper than an overhaul, which in the end guarantees you the best engine: own according to already existing documents and structurally absolutely new.
It is necessary to clarify the difference between overhaul and complete overhaul of the engine. The term “overhaul” is accepted to mean partial intervention, when worn out parts are replaced by nodes: such as replacement of valve guides, valve caps and camshaft. During reassembly, the cylinder-head cylinder head is ground and the gaskets are replaced.
If the engine is about to exhaust its entire life, it needs a complete overhaul: the engine will be completely disassembled, each element will be evaluated for degree of destruction, block and head will be checked for cracks and other traces of use, all clearances will be measured accurately. The cylinder-head will be flushed and grinded, if necessary the cracks will be repaired and welded, camshaft will be renewed or replaced with a new one, valves will be replaced, new hydro-compensators and valve seals will be installed. The cranking mechanism, the most important element in the engine’s operation, will be restored to its original condition. The block will be bored out to fit new pistons and piston rings, liners will be fitted as required, cracks will be repaired and liners will be replaced.
Yes, at the output it will be a brand new engine in its condition and parameters, which still needs to be assembled correctly and, importantly, started up correctly for the first time by adjusting the ignition and combustion systems. It is necessary to do so much, that no professional will be able to name at once the exact cost of such repair.
Both rebuilds and overhauls are expensive operations that can be avoided or, more likely, postponed. The right exploitation and timely maintenance, careful treatment and continuous monitoring will allow even the fragile, highly forced modern engines to please their owners for many thousand kilometres.
If they are “out of control”, then even the legendary engines of the past “millionaires” can’t resist the furious pace of the big city with its traffic jams and abrupt starts from traffic lights, absence of proper warming up and cooling, continuous running at high revolutions and abrupt stops. The iron also wears out. But in the right hands, it can do so extremely slowly.
Our tip: Do maintenance earlier than says the manufacturer, instead of 15-000 km, we recommend to do maintenance of the engine, with 8-12 thousand mileage, if the car is used in harsh conditions, then do maintenance every 7-9 thousand km mileage.
Having spent pair hundreds, once in 10 thousand, km. – It is much more favourable, than to spend pair thousand for major overhaul or replacement of the engine. And the most important, use only the checked up oil and consumables – economy is fraught with other problems.