If the owner of a new car from the date of purchase strictly adhered to the schedule of routine maintenance procedures (see Section Schedule of ongoing maintenance), performed checks of critical parameters quite often, maintained the required level of lubricating fluids, the engine will very rarely need to perform additional maintenance and refurbishment (beyond the replacement of wear-prone components and consumables).
On the other hand, in the case of a careless attitude to the implementation of regular maintenance procedures and frequent violations of the established deadlines for inspections, the efficiency of the engine's output will inevitably decrease sooner or later. The likelihood of such a situation is especially high in the case of purchasing a used car. In such cases, it becomes necessary to perform a set of settings for the power unit in excess of the amount of work on the current maintenance of the car.
The first step in tuning or troubleshooting an underpowered engine is always to check the compression pressure in the cylinders (see chapter Engine), the analysis of the results of which allows you to assess the general condition of the internal components of the engine and outline a plan for future adjustment and / or restoration work. For example, if a compression test reveals signs of serious internal engine wear, a simple set of adjustments will not be enough to correct the situation, and it will be a waste of time and money. Because of the value of information obtained from a compression test, it should be performed by a suitably experienced and qualified mechanic who has the necessary diagnostic tools.
Below are lists of basic tuning procedures that allow you to achieve maximum efficiency of return from an engine that is in good mechanical condition.
List of the minimum set of checks and adjustments
- Check the levels of all engine related fluids (see Section Checking fluid levels).
- Clean and check the condition of the battery (see Section Checking, maintaining and charging the battery).
- Check the condition and service the cooling system components (see Section Checking the Condition of the Cooling System Components).
- Check the condition of all hoses located in the engine compartment (see Section Check of a condition and replacement of the hoses located in an impellent compartment).
- Check the condition and function of the PCV valve (see Section Checking and replacing the valve of the controlled crankcase ventilation system (PCV)).
- Check the condition of the air cleaner element (see Section Replacing the air cleaner element).
- Check the condition of the spark plugs (Gas engine) (see Section Checking the condition and replacing spark plugs (gasoline engines)).
- Check the valve clearance setting and correct if necessary (see Section Checking and adjusting valve clearances.
- Check idle speed setting (see Section Checking and adjusting idle speed).
- Check the setting of the ignition timing angle, if necessary, make the appropriate adjustment (see chapter Engine electrical equipment).
- Check the condition and tension of the drive belts, if necessary, make the necessary adjustments (see Section Checking the condition, adjusting the tension and replacing the drive belts).
- (see Section Checking the Condition of Suspension and Steering Components).
List of the full range of checks and adjustments
In addition to the checks listed above:
- Check the condition and function of the EGR system (see Section Check of serviceability of a condition of components of system recirculation of the fulfilled gases (EGR)).
- Replace PCV valve (see Section Checking and replacing the valve of the controlled crankcase ventilation system (PCV)).
- Replace air cleaner element (see Section Replacing the air cleaner element).
- Check the correct functioning of the power system and the condition of its components (see Section Checking the status of power system components).
- Replace fuel filter (see Section Fuel filter replacement).
- Check the correct functioning of the ignition system and the condition of its components (see chapter Engine electrical equipment).
- Check the function of the charging system and the condition of its components (see chapter Engine electrical equipment).