Removal and Installation
Cylinder Head: Removal and Installation
NOTE:
When removing components such as hoses, tubes/lines, etc., cap or plug openings to prevent fluid from spilling.
Removal
1) Release fuel pressure. Refer to [Fuel Pressure Check: QR25DE] Testing and Inspection.
2) Drain engine coolant. Refer to [Changing Engine Coolant] Service and Repair.
CAUTION:
- Perform this step when the engine is cold.
- Do not spill engine coolant on drive belt.
3) Drain engine oil. Refer to [Changing Engine Oil] Service and Repair.
CAUTION:
- Perform this step when the engine is cold.
- Do not spill engine oil on drive belt.
4) Remove intake manifold. Refer to [Water Outlet and Water Piping: Removal and Installation] Intake Manifold Removal and Installation.
5) Remove fuel injector and fuel tube assembly. Refer to Removal and Installation.
6) Remove exhaust manifold and three way catalyst assembly. Refer to Exhaust Manifold and Three Way Catalyst Removal and Installation.
7) Remove water outlet. Refer to Water Outlet Removal and Installation.
8) Remove heater outlet. Refer to [Water Outlet and Water Piping: Exploded View] Water Outlet Exploded View.
NOTE:
Can be removed and installed even when assembled with cylinder head.
9) Remove front cover and timing chain. Refer to [Engine Unit: Inspection After Disassembly] Removal and Installation.
10) Remove camshafts. Refer to Removal and Installation.
11) Loosen cylinder head bolts in reverse order as shown using power tool.
12) Remove cylinder head.
13) Remove cylinder head gasket.
Inspection after Removal
Cylinder Head Bolts Outer Diameter
- Cylinder head bolts are tightened by plastic zone tightening method. Whenever the size difference between (d1) and (d2) exceeds the limit, replace them with a new one.
- If reduction of outer diameter appears in a position other than (d2), use it as (d2) point.
Cylinder Head Distortion
NOTE:
When performing this inspection, cylinder block distortion should also be checked. Refer to Inspection After Disassembly.
1) Using suitable tool, wipe off oil, scale, gasket, sealant and carbon deposits from surface of cylinder head.
CAUTION:
Do not allow gasket fragments to enter engine oil or engine coolant passages.
2) At each of several locations on bottom surface of cylinder head, measure the distortion in six directions.
- If it exceeds the limit, replace cylinder head.
Installation
1) Install new cylinder head gasket.
2) Install cylinder head following the steps below to tighten cylinder head bolts in numerical order as shown.
CAUTION:
If cylinder head bolts re-used, check their outer diameters before installation. Follow the "Cylinder Head Bolts Outer Diameter" procedure.
NOTE:
Apply new engine oil to threads and seating surfaces of bolts.
- Measure the tightening angle using Tool.
3) Installation of the remaining parts is in reverse order of removal.
Inspection after Installation
- Before starting engine, check oil/fluid levels including engine coolant and engine oil. If less than required quantity, fill to the specified level. Refer to [Recommended Fluids and Lubricants [for USA and Canada] [1][2]Maintenance ] (United States and Canada) or [Recommended Fluids and Lubricants [for Mexico] ] (Mexico).
- Use procedure below to check for fuel leakage.
- Turn ignition switch ON (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leakage at connection points.
- Start engine. With engine speed increased, check again for fuel leakage at connection points.
- Run engine to check for unusual noise and vibration.
NOTE:
If hydraulic pressure inside timing chain tensioner drops after removal and installation, slack in the guide may generate a pounding noise during and just after engine start. However, this is normal. Noise will stop after hydraulic pressure rises.
- Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oils/fluids including engine oil and engine coolant.
- Bleed air from passages in lines and hoses, such as in cooling system.
- After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill to specified level, if necessary.
- Summary of the inspection items:
*Power steering fluid, brake fluid, etc.