Toyota Prius: Cylinder Head

• Precaution
• Disassembly
• Inspection
• Reassembly
• Repair

Precaution

PRECAUTION

Disassembly

DISASSEMBLY

CAUTION / NOTICE / HINT

The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during engine unit removal/installation are shown below.

Necessary Procedures After Parts Removed/Installed/Replaced

Replaced Part or Performed Procedure	Necessary Procedure	Effect/Inoperative Function when Necessary Procedure not Performed	Link
*: Even when not replacing the part, it is necessary to perform the specified necessary procedures after installation. *1: Also necessary after performing a tire rotation. *2: It is not necessary to perform this procedure if the tire pressure warning valve and transmitters are installed to the same location.
Replacement of ECM	Update ECU security key	Toyota Prius Vehicle Control History (RoB) are stored
	ECU configuration	-
	Perform Toyota Prius Vehicle Identification Number (VIN) registration	DTC is output
Replacement of throttle body assembly Replacement of cylinder head sub-assembly Replacement of camshaft (for intake or exhaust camshaft) Replacement of camshaft timing gear assembly Replacement of fuel injector assembly Replacement of spark plug Replacement of ignition coil assembly Replacement of EGR valve assembly Gas leak from exhaust system is repaired Replacement of knock control sensor	Inspection after repair	Poor idle, etc. Engine start function, etc.
Replacement of inverter with converter assembly	ECU configuration	-
	Resolver learning	DTCs are stored Slight vibration at a Toyota Prius vehicle speed of 5 km/h (3 mph) or less Shock or vibration during acceleration
Replacement of hybrid vehicle transaxle assembly	Resolver learning Initialize resolver	DTCs are stored Slight vibration at a Toyota Prius vehicle speed of 5 km/h (3 mph) or less Shock or vibration during acceleration
Suspension parts	Rear television camera assembly optical axis (Back camera position setting)	Parking Assist Monitor System
	Parking assist ECU initialization	Panoramic View Monitor System
		Advanced Park
Tires	Initialization*1*2 Tire Position Identification*1*2	Tire Pressure Warning System	Refer to Procedures Necessary When Replacing Parts (for Tire Pressure Warning System) table below
	Rear television camera assembly optical axis (Back camera position setting)	Parking Assist Monitor System
	Parking assist ECU initialization	Panoramic View Monitor System
		Advanced Park
Replacement of front bumper assembly*	Front television camera view adjustment	Panoramic View Monitor System
		Advanced Park

HINT:

When the cable is disconnected / reconnected to the auxiliary battery terminal, systems temporarily stop operating. However, each system has a function that completes learning the first time the system is used.

CAUTION / NOTICE / HINT

COMPONENTS (DISASSEMBLY)

Procedure		Part Name Code
1	VALVE SPRING RETAINER ROCK	-		-	-
2	VALVE SPRING RETAINER	-	-	-	-
3	INTAKE VALVE COMPRESSION SPRING	-	-	-	-
4	EXHAUST VALVE COMPRESSION SPRING	-	-	-	-
5	INTAKE VALVE	13711	-	-	-
6	EXHAUST VALVE	13715	-	-	-
7	VALVE STEM OIL SEAL	-		-	-
8	VALVE SPRING SEAT	13734		-	-
9	NO. 1 STRAIGHT SCREW PLUG	11117E		-	-
10	INTAKE VALVE GUIDE BUSH	11122		-	-
11	EXHAUST VALVE GUIDE BUSH	11126		-	-
12	RING PIN	-	-	-	-
13	STUD BOLT	-	-	-	-

●

Non-reusable part

-

-

PROCEDURE

1. REMOVE VALVE SPRING RETAINER ROCK

(1) Using SST and wooden blocks, compress the inner compression spring and remove the 16 valve spring retainer locks.

SST: 09202-70020

09202-01010

09202-01020

SST: 09202-00021

2. REMOVE VALVE SPRING RETAINER

3. REMOVE INTAKE VALVE COMPRESSION SPRING

4. REMOVE EXHAUST VALVE COMPRESSION SPRING

(a) Perform the same procedure as for the intake side.

5. REMOVE INTAKE VALVE

6. REMOVE EXHAUST VALVE

(a) Perform the same procedure as for the intake side.

7. REMOVE VALVE STEM OIL SEAL

(1) Using needle-nose pliers, remove the 16 valve stem oil seals.

8. REMOVE VALVE SPRING SEAT

(1) Using compressed air and a Magnet Hand, remove the 16 valve spring seats from the cylinder head sub-assembly by blowing air onto them.

9. REMOVE NO. 1 STRAIGHT SCREW PLUG

NOTICE: If coolant leaks from a No. 1 straight screw plug or a plug is corroded, replace it.

(1) Using a 10 mm straight hexagon wrench, remove the 3 No. 1 straight screw plugs and 3 gaskets from the cylinder head sub-assembly.

10. REMOVE INTAKE VALVE GUIDE BUSH

(1) Heat the cylinder head sub-assembly to 80 to 100°C (176 to 212°F).

(2) Using SST and a hammer, tap out the intake valve guide bush.

SST: 09201-10000

09201-01050

SST: 09950-70010

09951-07100

11. REMOVE EXHAUST VALVE GUIDE BUSH

(1) Heat the cylinder head sub-assembly to 80 to 100°C (176 to 212°F).

(2) Using SST and a hammer, tap out the exhaust valve guide bush.

SST: 09201-10000

09201-01050

SST: 09950-70010

09951-07100

12. REMOVE RING PIN

13. REMOVE STUD BOLT

Inspection

INSPECTION

PROCEDURE

1. INSPECT CYLINDER HEAD SUB-ASSEMBLY FOR WARPAGE

(a) Using a precision straightedge and feeler gauge, check the surfaces which contact the cylinder head sub-assembly and manifold for warpage. Maximum Warpage: Item Specified Condition Result Bottom side 0.05 mm 0.00197 in. mm in. Intake manifold side 0.10 mm 0.00394 in. mm in. Exhaust manifold side 0.10 mm 0.00394 in. mm in.

*a Bottom Side *b Intake Manifold Side *c Exhaust Manifold Side

(b) If the warpage is more than the maximum, replace the cylinder head sub-assembly.

2. INSPECT CYLINDER HEAD SUB-ASSEMBLY FOR CRACKS

(a) Using a dye penetrant, check the intake ports, exhaust ports and bottom surface of the cylinder head sub-assembly for cracks.

(b) If cracks are found, replace the cylinder head sub-assembly.

3. INSPECT INTAKE VALVE

(a) Using a vernier caliper, measure the overall length of the intake valve. Standard Overall Length: Minimum Overall Length Specified Condition Result 108.84 mm 4.29 in. 109.34 mm 4.30 in. mm in. (1) If the overall length is less than the minimum, replace the intake valve.

*a Overall Length

(b) Using a micrometer, measure the diameter of the valve stem. Standard Valve Stem Diameter: Specified Condition Result 5.470 to 5.485 mm 0.215 to 0.216 in. mm in. (1) If the valve stem diameter is not as specified, check the intake valve guide bush oil clearance. HINT: Click here

(c) Using a vernier caliper, measure the valve head margin thickness. Standard Margin Thickness: Minimum Margin Thickness Specified Condition Result 0.5 mm 0.0197 in. 1.0 mm 0.0394 in. mm in. (1) If the margin thickness is less than the minimum, replace the intake valve.

*a Margin Thickness

4. INSPECT EXHAUST VALVE

(a) Using a vernier caliper, measure the overall length of the exhaust valve. Standard Overall Length: Minimum Overall Length Specified Condition Result 107.75 mm 4.24 in. 108.25 mm 4.26 in. mm in. (1) If the overall length is less than the minimum, replace the exhaust valve.

*a Overall Length

(b) Using a micrometer, measure the diameter of the valve stem. Standard Valve Stem Diameter: Specified Condition Result 5.465 to 5.480 mm 0.215 to 0.216 in. mm in. (1) If the valve stem diameter is not as specified, check the exhaust valve guide bush oil clearance. HINT: Click here

(c) Using a vernier caliper, measure the valve head margin thickness. Standard Margin Thickness: Minimum Margin Thickness Specified Condition Result 0.5 mm 0.0197 in. 1.0 mm 0.0394 in. mm in. (1) If the margin thickness is less than the minimum, replace the exhaust valve.

*a Margin Thickness

5. INSPECT INNER COMPRESSION SPRING

(a) Using a vernier caliper, measure the free length of the inner compression spring. Standard Free Length: Specified Condition Result 58.52 mm 2.30 in. mm in. Specified Condition Result 58.90 mm 2.32 in. mm in. NOTICE: Inner compression springs come in 2 different lengths. Make sure all inner compression springs are the same length when replacing them.

(b) Using a steel square, measure the angle of the inner compression spring. Maximum Angle (Reference): 2° (1) If the deviation is greater than the maximum, replace the inner compression spring.

*a Angle *b 40 mm (1.57 in.)

6. INSPECT VALVE GUIDE BUSH OIL CLEARANCE

(a) Using a caliper gauge, measure the inside diameter of the valve guide bush. Standard Valve Guide Bush Inside Diameter: Specified Condition Result 5.510 to 5.530 mm 0.217 to 0.218 in. mm in.

(b) Subtract the valve stem diameter measurement from the valve guide bush inside diameter measurement.

Standard Oil Clearance:

Item	Maximum Oil Clearance	Specified Condition	Result
Intake Side	0.080 mm 0.00315 in.	0.025 to 0.060 mm 0.000984 to 0.00236 in.	mm in.
Exhaust Side	0.085 mm 0.00335 in.	0.030 to 0.065 mm 0.00118 to 0.00256 in.	mm in.

HINT:

Oil clearance = Inside diameter - Valve stem diameter

(1) If the oil clearance is more than the maximum, replace the valve and valve guide bush.

7. INSPECT VALVE SEATS

Pre-procedure1

(a) Apply a light coat of Prussian blue to the valve face.

*a Width

(b) Lightly press the valve face against the valve seat.

NOTICE:

Do not rotate the valve while pressing it.

Procedure1

(c) Check the valve face and valve seat.

(1) If Prussian blue appears 360° around the entire valve face, the valve face is concentric.

(2) If the valve face is not concentric, replace the valve.

(3) If Prussian blue appears 360° around the entire valve seat, the valve seat and valve face are concentric.

(4) If the valve face is not concentric, resurface the valve seat.

HINT:

Click here

(5) Measure the width of the contact area of the valve seat and valve face.

Standard Width:

Item	Specified Condition	Result
Intake Side	1.0 to 1.4 mm 0.0394 to 0.0551 in.	mm in.
Exhaust Side	1.0 to 1.4 mm 0.0394 to 0.0551 in.	mm in.

Post-procedure1

(d) None

Reassembly

REASSEMBLY

CAUTION / NOTICE / HINT

HINT:

Perform "Inspection After Repair" after replacing the cylinder head sub-assembly.

Click here

CAUTION / NOTICE / HINT

COMPONENTS (REASSEMBLY)

Procedure		Part Name Code
1	SPARK PLUG TUBE	-		-	-
2	RING PIN	-		-	-
3	STUD BOLT	-		-	-
4	INTAKE VALVE GUIDE BUSH	11122		-	-
5	EXHAUST VALVE GUIDE BUSH	11126		-	-
6	NO. 1 STRAIGHT SCREW PLUG	11117E		-	-
7	VALVE SPRING SEAT	13734	-	-	-
8	VALVE STEM OIL SEAL	-		-	-
9	INTAKE VALVE	13711		-	-
10	EXHAUST VALVE	13715		-	-
11	INTAKE VALVE COMPRESSION SPRING	-		-	-
12	EXHAUST VALVE COMPRESSION SPRING	-		-	-
13	VALVE SPRING RETAINER	-	-	-	-
14	VALVE SPRING RETAINER ROCK	-		-	-

	N*m (kgf*cm, ft.*lbf): Specified torque	●	Non-reusable part
	Adhesive 1324	★	Precoated part

PROCEDURE

1. INSTALL SPARK PLUG TUBE

HINT: When using a new cylinder head sub-assembly, the spark plug tube must be replaced.

*a	Application Width	*b	1.0 to 13.0 mm (0.0394 to 0.512 in.)
*c	Protrusion Height	-	-

(1) Apply adhesive to the area of a new spark plug tube shown in the illustration.

Adhesive:

Toyota Genuine Adhesive 1324, Three Bond 1324 or equivalent

Standard Application Width:

1.0 to 3.0 mm (0.0394 to 0.118 in.)

(2) Using a wooden block and hammer, tap in the spark plug tube to the specified protrusion height.

Standard Protrusion Height:

122 mm (4.80 in.)

NOTICE:

To avoid tapping in the spark plug tube too far, measure the protrusion height while tapping it.

2. INSTALL RING PIN

(1) Using a plastic hammer, tap in 2 new ring pins to the specified protrusion height.

Standard Ring Pin:

Item	Height	Width	Protrusion Height
Ring pin	11.7 to 12.3 mm (0.461 to 0.484 in.)	12.0 mm (0.472 in.)	6.5 to 7.5 mm (0.256 to 0.295 in.)

3. INSTALL STUD BOLT

*a	Intake Manifold Side	*b	Exhaust Manifold Side
*c	Cylinder Head Rear Side	*d	55 mm (2.17 in.)
*e	13 mm (0.512 in.)	*f	26 mm (1.02 in.)
*g	24 mm (0.945 in.)	*h	49.5 mm (1.95 in.)
*i	20 mm (0.787 in.)	*j	42 mm (1.65 in.)

(1) Using E7 and E8 "TORX" socket wrenches, install the 9 stud bolts to the cylinder head sub-assembly.

Torque:

9.5 N·m {97 kgf·cm, 84 in·lbf}

4. INSTALL INTAKE VALVE GUIDE BUSH

*a

Height

-

-

(1) Using a caliper gauge, measure the intake valve guide bush bore diameter of the cylinder head sub-assembly.

Standard Intake Valve Guide Bush Bore Diameter:

10.285 to 10.306 mm (0.4049 to 0.4057 in.)

New Guide Bush Selection Chart (STD or O/S 0.05):

Bush Size	Bush Diameter
STD	10.333 to 10.344 mm (0.4068 to 0.4072 in.)
O/S 0.05	10.383 to 10.394 mm (0.4088 to 0.4092 in.)

(2) Heat the cylinder head sub-assembly to 80 to 100°C (176 to 212°F).

(3) Using SST and a hammer, tap in a new intake valve guide bush to the specified protrusion height.

Standard Protrusion Height:

9.9 to 10.3 mm (0.390 to 0.406 in.)

SST: 09201-10000

09201-01050

SST: 09950-70010

09951-07100

(4) Using a sharp 5.5 mm reamer, ream the intake valve guide bush to obtain the standard oil clearance between the intake valve guide bush and valve stem.

Standard Oil Clearance:

0.025 to 0.060 mm (0.000984 to 0.002362 in.)

5. INSTALL EXHAUST VALVE GUIDE BUSH

*a

Height

-

-

(1) Using a caliper gauge, measure the exhaust valve guide bush bore diameter of the cylinder head sub-assembly.

Standard Exhaust Valve Guide Bush Bore Diameter:

10.285 to 10.306 mm (0.4049 to 0.4057 in.)

New Guide Bush Selection Chart (STD or O/S 0.05):

Bush Size	Bush Diameter
STD	10.333 to 10.344 mm (0.4068 to 0.4072 in.)
O/S 0.05	10.383 to 10.394 mm (0.4088 to 0.4092 in.)

(2) Heat the cylinder head sub-assembly to 80 to 100°C (176 to 212°F).

(3) Using SST and a hammer, tap in a new exhaust valve guide bush to the specified protrusion height.

SST: 09201-10000

09201-01050

SST: 09950-70010

09951-07100

Standard Protrusion Height:

11.15 to 11.55 mm (0.439 to 0.455 in.)

(4) Using a sharp 5.5 mm reamer, ream the exhaust valve guide bush to obtain the standard oil clearance between the exhaust valve guide bush and valve stem.

Standard Oil Clearance:

0.030 to 0.065 mm (0.00118 to 0.00256 in.)

6. INSTALL NO. 1 STRAIGHT SCREW PLUG

HINT:

If coolant leaks from a No. 1 straight screw plug or a plug is corroded, replace it.

(1) Using a 10 mm straight hexagon wrench, install 3 new gaskets and the 3 No. 1 straight screw plugs to the cylinder head sub-assembly.

Torque:

44 N·m {449 kgf·cm, 32 ft·lbf}

7. INSTALL VALVE SPRING SEAT

8. INSTALL VALVE STEM OIL SEAL

*a	Intake side	*b	Exhaust side
*c	Gray	*d	Black
*e	Correct	*f	Incorrect

(1) Apply a light coat of engine oil to 16 new valve stem oil seals.

NOTICE:

Pay attention when installing the valve stem oil seals. For example, installing an intake side valve stem oil seal to the exhaust side or installing an exhaust side valve stem oil seal to the intake side can cause installation problems later.

HINT:

The intake valve stem oil seal is gray and the exhaust valve stem oil seal is black.

(2) Using SST, push in the 16 valve stem oil seals.

SST: 09201-41020

9. INSTALL INTAKE VALVE

*a

30 mm (1.18 in.) or more

-

-

(1) Sufficiently apply engine oil to the tip area of the intake valve shown in the illustration.

(2) Install the 8 intake valves to the cylinder head sub-assembly.

10. INSTALL EXHAUST VALVE

(a) Perform the same procedure as for the intake side.

11. INSTALL INTAKE VALVE COMPRESSION SPRING

NOTICE: Install the inner compression spring with its tapered side facing upward (towards the valve spring retainer). Install the same parts in the same combination to their original locations.

12. INSTALL EXHAUST VALVE COMPRESSION SPRING

NOTICE: Install the inner compression spring with its tapered side facing upward (towards the valve spring retainer). Install the same parts in the same combination to their original locations.

13. INSTALL VALVE SPRING RETAINER

14. INSTALL VALVE SPRING RETAINER ROCK

(1) Using SST and wooden blocks, compress the inner compression spring and install the 16 valve spring retainer locks.

SST: 09202-70020

09202-01010

09202-01020

SST: 09202-00021

(2) Using a plastic hammer, lightly tap the valve stem tip to ensure a proper fit.

Repair

REPAIR

PROCEDURE

1. REPAIR VALVE SEAT

(a) Using a 45° cutter, resurface the valve seat so that the valve seat width is more than the standard.

(b) Using 30° and 75° cutters, resurface the valve seat so that the valve contacts the entire circumference of the valve seat. The contact should be in the center of the valve seat, and the valve seat width should be maintained within the specified range around the entire circumference of the valve seat. Standard Valve Seat Width: 1.0 to 1.4 mm (0.0394 to 0.0551 in.)

*a Valve Seat Width

(c) Hand lap the valve and valve seat with an abrasive compound.

(d) Check the valve seating position.