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Autopapyrus · BYD Denza D9 1.5 Turbo PHEV (2024)
https://autopapyrus.com/guides/byd/denza-d9/intake-manifold-removal-and-installation/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

BYD Denza D9 1.5 Turbo PHEV (2024): Intake Manifold Removal and Installation

The exact procedure for this model and engine is not documented in publicly available service materials. Below is the general principle for an inline 4-cylinder turbo engine with a plastic manifold, as fitted to this PHEV. Check the sequence and fastener locations against the manufacturer's service manual. The engine works together with a high-voltage system, so you must make sure it cannot start accidentally before you begin.

Difficulty: Hard Time: 2-4 hours Steps: 15

Parts

3
№Part
01 Intake manifold gasket set (BYD 1.5T engine)
02 Intake pipe and fuel rail sealsif the rail is removed
03 Intake manifold assemblyif needed

Tools

8
  • Socket set and ratchet
  • torque wrench (5-50 N·m range)
  • extensions
  • Torx set
  • flat-head screwdriver
  • hose clamp/clip removal tool
  • plastic plugs for intake ports
  • multimeter or OBD scanner

Step by step

15 steps
  1. Put the vehicle in the off state and move the key or fob at least several meters away from the cabin. The engine in a hybrid can start on its own, so make sure power is fully shut down. Work only on the fuel system and intake, and do not touch the high-voltage components. If you need to get near the orange HV cables, first disconnect the high-voltage battery service plug and wear 1000 V dielectric gloves.
  2. Wait for the engine to cool down. Disconnect the negative terminal of the 12 V battery and wait at least 10 minutes.
  3. Remove the decorative engine cover and, if necessary, the underbody protection panel under the engine.
  4. Relieve the residual pressure in the fuel system: remove the fuel pump relay or fuse and let the engine run until it stalls, if it starts. On a direct-injection PHEV the pressure in the rail can be very high, so cover the area with a rag when removing the fuel lines, and do not open the rail without relieving the pressure first.
  5. Remove the air filter with its housing and the intake pipe from the turbocharger and intercooler to the throttle body. Unclip the connectors of the air pressure and temperature sensors and photograph the routing of the hoses.
  6. Disconnect the vacuum hoses, the crankcase ventilation hose, the charcoal canister purge hose, and the EGR pipe (if equipped) from the manifold. Label each hose.
  7. Disconnect the throttle body connector and the intake pressure sensor. The throttle body can be removed together with the manifold as an assembly; it is better not to disassemble it separately.
  8. If the fuel rail or hoses are in the way, remove them after first checking that there is no pressure. Plug the open fuel fittings.
  9. Remove the manifold fasteners from the cylinder head, starting with the outer bolts, then working toward the center, then take off the manifold. Do not pull on the plastic. If it does not come off, check for hidden brackets and bolts.
  10. Immediately cover the cylinder head intake ports with a clean lint-free cloth or plugs so that bolts and debris cannot fall inside.
  11. Clean the cylinder head mating surface of gasket residue without scratching the metal. Inspect the manifold for cracks and check the flaps for wear. Replace the gaskets and seals with new ones.
  12. Install in reverse order. Tighten the manifold fasteners with a torque wrench from the center outward in 2-3 passes. The torque for a plastic manifold is usually low, roughly 8-25 N·m (6-18 lb-ft); use the exact value from the manufacturer's service manual.
  13. Reconnect all connectors and hoses according to your labels and check the tightness of the pipe clamps. Torque values for the fuel fittings and the rail, if they were removed, must come only from the manufacturer's service manual.
  14. Reconnect the battery and turn the ignition on for a few seconds so the fuel system builds pressure, then inspect the connections for leaks. Start the engine and check that the idle is smooth, that there are no air leaks (hissing) and no fault codes. If necessary, perform a throttle body adaptation with a scan tool.
  15. After a test drive, check again for fuel leaks and air leaks.

Common mistakes and warnings

  • Working with high-pressure fuel and the hybrid's high-voltage system is dangerous
  • If you have no experience with PHEVs and direct-injection fuel systems, leave the job to a repair shop
  • Do not start the engine with the intake ports open, and keep a fire extinguisher nearby