Hyundai Tucson:  Repair procedures

Hyundai Tucson - Fourth generation (NX4) - (2020-2023) - Workshop Manual / Engine Mechanical System /  Repair procedures

Compession Pressure Inspection


If the there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure.

  1. Start the engine and turn the coolant temperature to 80 - 95 ºC and stop.
  2. Remove the engine cover.

(Refer to Engine and Transaxle Assembly - "Engine Cover")

  1. Remove the ignition coils.

(Refer to Engine Electical System - "Ignition Coil")

  1. Remove spark plugs.

(Refer to Engine Electrical System - "Spark Plug")

  1. Disconnect the injector connector (A).

  1. Check the cylinder compression pressure.

(1) Insert a compression gauge into the spark plug hole.

(2) Fully open the throttle valve.

(2) Fully open the throttle valve.

(3) While cranking the engine, measure the compression pressure.


Always use a fully charged battery to obtain engine speed of 200 rpm or more.

(4) Repeat steps (1) through (3) for each cylinder.


If you need to check the compression pressure for more than three times, restart the engine to restore the lubrication condition to be normal and then check the compression pressure again.

Compression pressure

Standard : 1,127.76 kPa (11.5 kgf/cm², 164 psi) (200-250 rpm)

Minimum : 980.66 kPa (10.0 kgf/cm², 142 psi)

Difference between each cylinder : 98 kPa (1.0 kgf/cm², 14 psi) or less

(5) If the cylinder compression in 1 or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (1) through (3) for cylinders with low compression.

  • If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
  • If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket.
  1. Connect the injector connector (A).

  1. Install the spark plugs.

(Refer to Engine Electrical System - "Spark Plug")

  1. Install the ignition coil.

(Refer to Engine Electical System - "Ignition Coil")

  1. Some DTCs may exist after the inspection test and may need to be manually cleared with diagnostic tool.
  2. Install the engine cover.

(Refer to Engine and Transaxle Assembly - "Engine Cover")


     Timing System

     Timing System - Replacement

    Components Variable force solenoid valves Timing chain cover Cam to cam guide Timing chain Timing chain tensioner arm Timing chain tensioner arm Timing chain tensioner Crankshaft sprocket Oil pump chain Oil pump chain tensio

     Timing System - Installation

    Keep the liquid gasket sealing surfaces (timing chain cover, cylinder head, cam carrier, cylinder block, lower crankcase) free from foreign matters, cured sealant, oil, dust, moisture and etc. Spray the cleaner on the sealing surface and


     Seat  heater (Ventilation)

    Components Seat cushion heater (Ventilation) Seat heater (Ventilation) unit Seat back heater (Ventilation) Circuit Diagram Inspection Driver/Passenger Check for continuity and measure the resistance between terminals.


    Opening the hood Park the vehicle and set the parking brake. Pull the release lever to unlatch the hood. The hood should pop open slightly. Go to the front of the vehicle, raise the hood slightly, push up the secondary l