Engine and ECU Repair

What is an ECU and how does it relate to the engine?

  • The engine is the heart and the ECU (Engine Control Unit) is the brain of every vehicle. 
  • More often than not, the correct diagnosis by a professional service provider can get your vehicle's engine or ECU unit repaired speedily and in a surprising cost-efficient way!
  • Things like replacing a faulty sensor, resetting faulty engine codes or dashboard errors, reprogramming the ECU to checking the ignition coil, spark plugs, glow plugs and the thermostat might solve the problem. 
  • Find professional help 24/7 in the autorepairdirectory.co.za

Understanding the Engine:

A modern vehicle engine is a collection of advanced parts and systems that provide the driving force. Advanced electronics and materials may have made repairing engines more complicated, but the basic engine layout has not really changed over the years. Regular services that include oil and filter (air, oil, and fuel) changes go a long way to prevent costly repairs such as engine rebuilt or reconditioning of leaves and pistons, replacing timing belts, chains, bent valves, etc.

The best way to understand how your vehicle's engine works and the various parts, are to explore each part's function.


Most engines have 4, 6, or 8 pistons that move up and down in the cylinders. On the upper side of the piston is what is called the combustion chamber where the fuel and air mix before ignited. On the other side is the crankcase which is full of oil. Pistons have rings which serve to keep the oil out of the combustion chamber and the fuel and air out of the oil. Pistons are made from lightweight aluminum alloy and are designed to float in the cylinder without contacting the cylinder walls. They float on a thin layer of oil which is below the rings. If the rings fail, oil can leak into the combustion chamber and you will see grey smoke coming from the exhaust. If the rings wear or you lose oil to the engine, the pistons can score the cylinder walls damaging the engine and requiring a rebuild.

Rings seal the combustion chamber from the crankcase. The rings over time tend to wear out. When they wear they allow the fuel and air to enter into the oil and dilute it. This dilution reduces the oil's ability to lubricate your engine and can cause premature wear. Also if the rings wear down they can allow oil from the crankcase to enter the combustion chambers. This will result in oil being burned and exiting the exhaust as excessive smoke.


The crankshaft is connected to the pistons via a connecting rod. As the piston moves up and down in the cylinder it rotates the crankshaft and converts the straight-line motion into rotary motion. The crankshaft rides on bearings which can wear down over time. The bearings support the crankshaft and also the rods which connect the pistons to the crankshaft. A loud medium pitched knocking noise in the engine points to warn bearings most of the time. This is usually a costly repair and involves removing the crankshaft and either machining the surface where the bearings ride or replacing the entire crankshaft.


The valvetrain consists of valves, rocker arms, pushrods, lifters, and the camshaft. The valvetrain lets air and fuel in and out of the engine at the proper time. The timing is controlled by the camshaft which is synchronized to the crankshaft by a chain or belt. If a vehicle release grayish/white smoke at start-up it might have leaking valve seals. Valve seals keep oil from above the valve from leaking into the combustion chamber. When they wear, they can allow the oil to seep into the combustion chamber and collect there until one starts the engine again. Ya

Timing Chain or Belt:

Another common problem is the timing chain or belt will slip or even break causing the camshaft to stop rotating. Remember the camshaft tells the valves when to open and if it stops spinning then the valves stop opening and closing. This is why most manufacturers recommend changing the timing chain or belt every 80,000 kilometers. Timing belts dry out, stretch and deteriorate over time, therefore changing the belt as per the vehicle manufacturer's recommended schedule

Posted on May 21, 2020 by Auto Repair Directory

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