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Car related

This is about gasoline (benzine in Dutch) cars unless otherwise noted

Always cover the VIN number if it is visible from the outside


5W30Denotes the viscosity of (engine) oil. W stand for winter. The 5 in this example denotes the viscosity at -17 °C (0 °F). The 30 is the viscosity at 100 °C (212 °F)
CGICharged Gasoline InjectionMercedes Benz
ECUEngine Control Unit
EGRExhaust Gas Re-circulation
EPCElectronic Power ControlHas to do with the electronic systems
ESPElectronic Stability Program
MAP sensorManifold Air Pressure sensor

Fuel injection

The different types of fuel injection are explained in this video
GDI (Gasoline direct injection ) is direct injection
FSI (dutch) (Fuel Stratified Injection) is the Volkswagen term for direct injection. However in after a software update stratified injection is turned of in FSI engines. Only Homogeneous charge mode is used

What we do not want in a car

  • A direct injection motor (choose a multipoint injection motor). This can troublesome because of
    • dripping injectors
    • coal on the inlet valves which can lead to burned valves and / or engine knock
  • A lot of electronics. The more features a car has the more can lead to (expensive) repairs

Buying tips

  • If possible bring somebody (payed) with car knowledge to inspect the car
  • Make sure the car has been well taken care of and been well maintained
  • Have the car lifted up to and inspect the bottom
  • Check if the “Check engine light” turns on when you turn on the ignition. If it does not turn on walk away from that car
  • Check with an OBD-II reader if you can read the number of kilometers the car has driven and if it is the same in the dashboard

Avoiding motor damage

General and others

  • Find yourself a good repair shop which knows what they are doing. Who uses the manuals of the manufacturer, components of the manufacturer, torques bolts, spark plugs and others to the right torque
  • When working on the electrical circuit of a car without the engine running use a battery maintainer


  • Check the oil level every 1.000 km. Oil, as does coolant, also cools the engine. A too low oil level can damage the engine
    • Modern cars, with low tension piston rings, use oil. It is considered normal. The usage, even on new cars, can be up to one liter every 3.000 kilometer
    • Do not use motor oil with plasticisers. They might keep the valve seals in good order but also can damage gaskets which can lead to motor damage. For instance coolant in the motor oil
    • Do not use oil with parafine added
    • Use the advised oil. Using thicker oil can result in the oil filter valve to open, especially when the engine is cold, with engine damage as a result
    • When checking the oil level (and adding oil) make sure the engine is fully hot. When the engine is hot the level will be higher than with a cold engine. So the risk of overfilling, which can damage the engine, is less
    • In a car with variable valve timing use the advised oil. Using an other oil type like changing from 10W40 to 0W20 in can result malfunctioning of the valve timing and also in an error code getting thrown
    • Always use the same oil. Even between oil changes. Otherwise the additives can interact in a harmful way
    • It is advisable to change the oil often even if your car has long live oil which has to be changed every 30.000 km. Change the oil every 10.000 - 15.000 km or at least once a year, preferably before winter time.
      • If you drive much short distances, drive much in urban areas, cities, it is advisable to change the oil every 6000 km.
      • Big particles will be filtered by the oil filter (check the oil filter for particles when it is removed. Other contamination stays in the oil and might wear out parts of the engine like the timing chain (if there is one in the engine).
    • Change the oil filter when changing oil. The oil filter can get saturated and thereby not do its job anymore. Resulting in the oil overflow valve to open because of the high oil pressure. This can damage the engine because of the unfiltered oil entering the engine
      • Make sure to use a good oil filter. When the oil filter does not have sufficient capacity to let the oil through the oil pressure can become to high. This can result in the opening of the oil overflow valve. When this happens unfiltered oil is fed to the engine and this can lead to engine damage


  • Oil is bad for rubber parts like hoses

Oil Facts and Myths

Engine parts

  • A timing chain in a well-maintained engine can last up to 500.000 kilometers or more. Check the chain tension every year
  • When replacing parts always check if they comply to the specification. There are a lot of badly manufactured parts now a days even from well known manufacturers


  • Flush the cooling system clean every 60.000 km and replace the coolant. The corrosion protection of the coolant wears out over time

Direct injeciton

  • When driving a car with direct fuel injection be aware that these injectors can malfunction and drip. This can damage the engine. We prefer multipoint injection also called port injection
  • When driving a car with direct fuel injection the input valves are not cleaned by the fuel. Adding a cleaning additive (every 10.000 kilometer) to the fuel can prevent carbon buildup on the input valves

Engine knock

Spark plugs

To avoid engine knock it is important that spark plugs are torqued to the right value
Once torqued to tight they can not be reused again


  • Make sure you use the right fuel. The higher the octane rating the more knock resistant the fuel is
  • Adding a cleaning additive to the fuel every 10.000 kilometers can help to prevent excessive carbon build up

Knock sensor

The knock sensor is mounted on the motor block. You can see it as a microphone. They are fine tuned to the vehicle

It is used for fine tuning the ignition timing. It warns the computer that ignition has taken place before the computer activated the firing of the spark plug. This can happen when the cylinder head is not clean, when it contains coal. The coal stays hot between ignitions. This can lead to pre ignition by the coal. This can lead to engine damage like burned pistons

They can be resistive (old) of piëzo electric (new)
The piëzo type knock frequency is in the 6 to 9 kilo Hertz range. They produces their own electricity
The knock sensor should, mostly, be Torqued to 20 Nm

Bad sensor signs

  • Pinging sound caused by pre ignition
  • Less power, misfires
  • Low kilometer per liter fuel rates
  • If the check engine light is on the computer can have issued knock sensor related code. If so,
    • Check the cable and the connectors for issues
    • Check if there is oil in the connectors
    • Do the sensor test

Sensor test

Measure the resistance. On a Bosch sensor for a Golf IV 1J1 1.6 16v engine the resistance is 4,9 M Ohm

To test a piëzo electric sensor:

  • Disable the fuel pump by removing the relay for it
  • Attach an oscilloscope to the active knock sensor wire (the other one is ground)
  • Start the engine
  • Put it in first gear
  • Put load on the engine by putting your foot on the break and tring to move the car
  • Now the engine should knock


When the knock sensor is replaced it might be needed that the ECU needs to be told, learned, that a new knock sensor is installed

Dashboard indicator

You can use the sensor to make an knock indicator on the dashboard. This might be difficult since probably a DSP (Digital Signal Processor) has to be used to filter out the needed signals
Some background:

Air conditioning

Warning: To avoid damage use the airconditionging every month for at least half an hour at one time. This avoids the gathering of a big part of the oil in the system in the compressor. To much oil in the compressor can damage the compressor because it tries to compress oil, which is NOT compressable, in stead of the coolant gas, which is compresable

The temperature should be beween 5 °C and 10 °C. This temperature should be reached, at an ambient temperature of about 20 °C within 2 minutes when the temperature is set to its lowest value. Mostly indicated by LO

Make sure airflow through the condensor in the front of the car is not blocked, Make sure the fan(s) are working properly

Warning: When you do not use the air conditioning for years the dryer cartridge needs to be replaced. The dryer removes moisture from the system

Warning: Only use de factory default coolant in the air conditioning. Otherwise, in case of an emergency, dangerous situations can occur

At the end of the journey switch of the air conditioning and let the car run for a few minutes with the heater on so the moisture can get out of the evaporator. This can avoid bacterial buildup and thereby smels in the interior of the car


Cars from before 2010 with coollant R134a: Every 2 years
Cars from 2010 and newer with coollant R134a: Every 3 year. By law they may not lose more than 40 gram coollant per year
The new coolant is: R1234yf


  • Using to much additives can damage the motor
  • Cleaning to fast can damage the motor. Dirt can block oil channels


  • Prevent motor wear
  • Make an motor cleaner, remove slam


  • Clean fuel injectors
  • Clean (intake) valves


  • Check the hoses every 60.000 kilometer for wear


  • Check if the catalyst is not broken by nocking on it. If it is broken parts can block the exhaust


It is advised to use the same type of tires with the same speedindex on all wheels. If you mix put the tires with the lowest speedindex on the front axle


Pxxx/yyNzz llS
Example: K205/50R22 87H

PTire classP: Passenger Car, LT: Light Truck, ST: Special Trailer, T: Temporary space-saver spare wheel
xxxTread width
yyAspect RatioWidth (of the tread) / height (rim to tread)
NTire constructionD: Diagonal, R: Radial
zzRim diameterIn inches
llTire load index
SSpeed rating

Tire load index


Speed rating

Indicator Maximum speed (kilometer per hour)

European tire label

Fuel efficencyA to G (D is not used) can make up for 7,5%. So about 1% per step
Grip in rainA to F can make up for 18 meters in brake path at 80 kilometers per hour. So about 3 meters per step. It is also tire dimension dependent
Sound3dB more is double the sound energy

Useful links

Tire code on Wikipedia


  • Do not use copper paste, use ceramic paste. Paste with metal can be harmful for the ABS system


The VCDS Scan Tool takes a long time to read data on cars approximately older than 2005
Software and hardware:


Waring: The ELM327 Bluetooth dongle uses power when the car is off. Do not leave it connected when you do not use it

CAN bus

HS-CAN500 kbaud11-bit messagesELM327 protocol 6
MS-CAN125 kbaud11-bit messagesELM327 protocol B


All apps

  • Free version
  • Have almost only gauges for parameters you already know. Only the payed version has more useful gauges.
Torque Lite
OBD Auto DoctorCan reset trouble codes
OBD MaryRuns the vibration and it can not be turned off. Annoying “Rate me” widgets. Only one interesting gauge at a time

Useful links

Vehicle electricity consumption

ModelYear25km/h90 km/h120km/h
Bicycle 6 Wh/km
Tesla Model S2010 170 Wh/km220 Wh/km

Sensors and meters

  • Battery voltage meter
  • Oil change indicator. Calculates the right time for an oil change depending on where the car has been driven like highway or city rate
  • Oil pressure sensor and meter with audible alarm
  • Oil temperature sensor and meter with audible alarm
  • Throttle position meter

Golf IV 1.6 16V sensors

  • Knock sensor
  • Crank sensor
  • Camshaft sensor
  • Speed sensor
  • RPM sensor
  • Coolant temperature sensor
  • Fuel amount sensor
  • Oil level sensor (2 levels (half (orange light) and bottom (red light))). Between full and half is one liter. The total amount of oil is 3,5 liters
  • Mass Airflow Sensor
  • Throttle body potentiometer
  • Lambda sensor also called oxygen sensor or Air Fuel Ratio sensor. Do not use rust remover when replacing one. This might damage the lambda sensor. It is advised to clean the lambda sensor every 30.000 kilometers. Otherwise replace it when the check engine light turns on and the lambda sensor code is activated
  • ABS sensor
  • Lateral acceleration sensor G200 (only on cars with ESP)
  • Brake pressure sensor G201 (only on cars with ESP)
  • Yaw rate sensor G202 (only on cars with ESP)
  • Steering Angle Sensor G85 (only on cars with ESP)

Turbo charger


  • The engine oil gets more hot and thereby degrade faster
  • There is some lag, time delay, before the extra power is present
  • Less reliable than a super charger

Super charger

German: Kompressor

  • Less efficient than a turbo charger

Cylinder head considerations

When does the cylinder head have to be removed

  • When the cylinder head gasket needs to be replaced. A bad gasket can be caused by
    • an overheating engine
    • bad coolant fluid (replace it every 60.000 kilometers)
  • When the pistons and /or piston rings need to be checked and / or replaced without removing the crankshaft

Removing the cylinder head might make it necessary, if it is warped (too bad), to machine the head to make it flat again. Disadvantages:

  • If to much is machined off the valves can hit the piston
  • The timing of the cams can be retarded so much, the computer can not compensate for it

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car_related.txt · Last modified: 13-09-2023 18:22 by wim