Engine Health Diagnosis – Explained

Engine Health Diagnosis – Explained

There is no easy way to determine the “health” of a car engine. Traditional methods of checking an engine is to do a physical inspection of its various components – oil viscosity and levels using a dipstick, coolant levels, battery voltage, belt conditions etc. This is largely based on judgement and dependent on the skill / experience of the technician carrying out the inspection and not really scientific.

Cartisan in partnership with EngineCal now provides Engine and Battery Health Diagnosis for your car based on analysis of real engine data (as a supplement to the carrying out physical inspection).

The diagnostics report gives a set of scores to the various sub-systems in the engine and this article details what the diagnosis actually tells you.

Coolant System – The coolant acts as a medium of heat transfer in the engine cooling the engine block. The coolant circulates inside the engine block, absorbing heat and then it dispels it to the atmosphere through the radiator. This score is useful to determine the condition of the coolant system of the engine. If it gives out a low rating, the following could be the problems associated with it:

Low Coolant levels – If the coolant in the system is insufficient, it will lead to overheating of the engine block. Check coolant levels in the reservoir and if found low, top up until it reaches the desired levels, as indicated by demarcations on the coolant reservoir.

Engine oil low – Apart from lubricating the engine, engine oil is also responsible for transfer of heat from parts of the engine to the external atmosphere. Hence, if the engine oil is in poor condition or is at a low level, the coolant system rating could be low. Check the engine oil viscosity and oil level using the tradition dipstick method to confirm the need for an oil change. Oil top ups are generally not recommended as intermixing of viscosities will affect the functionality of the engine oil inside the engine block.

Thermostat Malfunction – The thermostat regulates the coolant flow into the radiator. If the valve is damaged, it can cause excessive heating of engine due to reduced circulation of the coolant. You will need the help of a technician to identify whether the thermostat is damaged and needs replacement.

Radiator Fan Malfunction – The radiator fan forces air to pass on through the radiator which takes away the heat from the coolant. If this fan fails, it will lead to reduced heat extracted from the engine, thereby increasing engine temperature beyond desired values, which in turn can cause inefficient combustion and engine blowout or seizure. An qualified car electrician will need to check if the fan is faulty (motor and wiring) and if found faulty will need repair or replacement.

Radiator Clogging – If the radiator of the car is clogged with dirt and dust, it will cause inefficient transfer of heat from the system to the external atmosphere thereby causing the engine operating temperature to rise. The radiator assembly will need to be removed and cleaned and replaced in order to resolve this issue. If there are any leaks or damages sustained by the radiator, it’s recommended that it be replaced immediately.

Battery System – The key components in a car’s electrical system – The battery, Starter Motor and Alternator. When you start the car, the starter motor draws electrical energy from the battery to crank the engine. While the engine is running, the alternator recharges the battery. A low score here could mean the following:

Old or expired battery – If the battery has run longer than its lifetime, i.e 4yrs +, and is suffering from low voltage, the battery can either be recharged, distilled water can be topped up or preferably, replace the battery (at very low scores). If the battery is relatively new (6 months to 2 years) then the following could be the issues.

Alternator malfunction – The alternator might not be recharging the battery properly once the engine’s ignition is switched on. If the voltage of the alternator does not lie within specified ranges, it can be deemed that there’s a problem with the alternator. Depending on the damage, the alternator can either be overhauled or will need to be replaced. This is subject to dismantling and inspection.

Accessory fittings – There could be aftermarket accessory fittings that are drawing too much power from the car’s battery. Eg: Projector Lights, Music systems, Speakers etc. Identify if any such fittings exist in the car and check their power rating and whether they are equipped with relays or ballasts. If any of these components are damaged in these accessories it can cause excessive power consumption and hence draining of the battery.

Starter Motor malfunction – A starter motor might consume excessive amounts of power from the car’s battery if it sustains damage to any of its components. If the starter motor is damaged, the vehicle will not crank smoothly or will not crank at all. The starter motor will have to be removed, dismantled and checked to identify whether an overhaul or replacement is necessary.

RPM Oscillation analysis – Main causes for a poor rating here could be:

Poor condition of Engine Block Bore – the cylinder bore of the car’s engine can be subject to deterioration caused by
Contamination (sediments, dust) in the fuel injected or air entering into the cylinder,
Poor cooling and lubrication of the engine block because of deteriorated engine oil,
Clogged fuel injectors could result in a misfire in the specific cylinder thereby causing a low rating in the RPM oscillation analysis. This deduced by excessive vibrations or rattling sounds when the engine is in idle, drop in fuel economy and power output. Clogged fuel injectors to be removed and checked. If found clogged, a simple process called injector flushing can be done by adding a chemical called Diesel Injector Flush to the fuel of the car which can unclog the injectors.
Throttle body clogging – if the throttle body is clogged, it will result in improper injection of fuel into the cylinders, thereby causing the engine to misfire. The throttle body can be removed, cleaned and placed back inside the car which will most likely solve the problem. Throttle body clogging can result in drop in mileage, excessive vibrations while idling and reduced power output.

Damaged engine mounts – If the engine mounts, which fastens the engine block in the vehicle body, are damaged, can lead to a poor rating of RPM oscillation analysis. Engine mounts can be checked visibly by inspection from underneath the car as well as a drive test. A physical symptom of a damaged engine mount would be a rattling sound that emanates from the bottom of the engine bay near the front wheels, especially when the car runs into a pothole.

Loose Belts and Tensioners – Belts and tensioners transfer power to various auxiliary components such as the water pump, air conditioning compressor, power steering pump, alternator etc. It is simple to check whether the belt/tensioner is loose by inspection of the engine bay. If found loose or damaged, they would need to be replaced. Typical symptom of a loose belt or tensioner is a screeching sound from the engine when applying throttle. Also, if the surface of the belt develops cracks or looks too slick, it’s time for a replacement. Worn out belts and loose tensioners can also lead to a drop in mileage and power output.

Turbocharger System – for a turbocharged vehicle, a poor rating for the operation of this system can be caused due to the following:

Clogged Air Filter – If the air filter is clogged / dirty, it will restrict airflow into the engine thereby causing lesser boost pressure for the functioning of the turbocharger. Air filter needs to be inspected and needs cleaning / replacement.

Leakage in Ducting – If there’s a leakage in the piping/ducting of the air intake system, it will lead to a loss in boost pressure which would result in a poor rating. Check the ducting leading from the intake to the air filter and from air filter to the engine. Check all clamps to ensure the ducting is fastened properly. If not, tighten clamps or replace ducting, as per inspection. Leakages in ducting can be identified by the sound of high pressure air escaping through cracks in the ducting or loose fittings.

Play in turbocharger turbine – this can be caused due to worn out bearings in the turbocharger. Turbocharger failures are extremely rare and is almost always caused due to rash driving or extreme strain on the engine. If the bearing is damaged, lubricant oil will seep into the compressor turbine which will cause the turbocharger to fail. In this case a replacement is in order or a turbocharger overhaul, which can only be determined based on physical inspection.. Physical symptoms could be loss in power or pick up of the vehicle.

Fuel System – Fuel system will garner a low rating due to the following reasons:

Injector Clogging – if the fuel injector is clogged, it will lead to inefficient combustion. This will result in loss of fuel pressure which in turn means reduced fuel economy. In order to address injector clogging, one can use an Injector Flush. This is a fuel additive and when this fuel flows through the injectors into the cylinder, it will flush out all the contaminants that are clogging the injector.

Fuel Filter clogging – If the fuel filter is clogged, it can lead to restricted supply of fuel to the engine leading to inefficient combustion, thereby loss of power and fuel economy. There is also a risk of decontaminants circulating within the fuel system as a result of a clogged fuel filter. The fuel filter can be removed, inspected and replaced.

Note : in cases of Naturally Aspirated engines, i.e engines that don’t have a turbocharger or a supercharger, the diagnostic report will not show a rating for the fuel system.

Combustion Pressure

In very simple terms, this looks at the pressures inside the engine cylinder during the combustion cycle and determines if the engine is generating sufficient power as rated.

The compression pressure system rating directly depends on the condition of the Fuel System, Air/Turbocharger System, RPM Oscillation Analysis and the condition of the Engine Oil. The combined ratings of these systems affect the ratings of the Compression Pressure system

Diagnostic Trouble Codes (DTCs)

The test will also scan for any kind of diagnostic trouble codes which exists in the car’s ECU. Based on these error codes, one can identify damaged parts/sensors which will provide clear direction in identifying and resolving the problem.

A complete test report is available in the Cartisan app with remarks and a rating out of 10 which will determine the overall health of the car’s engine and battery. The rating also takes into account the severity of the problems in terms of the amount of money that will need to be spent in order to replace/repair the parts in question.