The steps below are shortened from the Vauxhall TIS pages for the Speedster. The VX220 shares the same engines and most of the car, but check anything unusual against your own car. The TIS pictures and the full wording aren't reproduced, so use the workshop manual if you are doing the job. We haven't seen owners' accounts of this job, so there are no owner tips here.
Engine-out or head-off work. For the timing belt itself see Turbo cam belt change. The torque and clearance figures are on Torque values and Turbo engine data.
Other jobs from the same factory chapter: Camshafts, pulleys, oil seal and sensor (Turbo).
Valves: removal
Turbo (Z20LET) only.
Install
- Special service tools required:
- Assembly tool set KM-6215, installation/removal set MKM-6086
- Note: All attaching parts such as camshaft(s) and hydraulic valve lifters are removed.
- Attach side mounts KM-6215-5 for lever KM-6215-4 to assembly device KM-6215-1. Attach lever KM-6215-4.
- See operation "Cylinder head, disassemble", "Cylinder head, assemble".
Valves: replacement
Turbo (Z20LET) only.
Remove
- See operation - “Cylinder Head, Attaching Parts, Remove and Install (Z20LET)”
Install
- See operation - “Cylinder Head, Attaching Parts, Remove and Install (Z20LET)”
Valve installation height check
Turbo (Z20LET) only.
Measure
- Special service tools required:
- Caliper Gauges, KM-419 (OHC I), KM-512 (OHC II), Measuring Bridge KM-301, Dial Gauge MKM-571-B
- Preconditions:
- Cylinder head sealing surface and valve heads are cleaned.
- The installation height of the valves can be checked from both the underside and from the upper side of the cylinder head.
- Valve indentation can be determined using Measuring Bridge KM-301 and Dial Gauge MKM-571-B.
Assemble
- If the valve indentation cannot be determined, the extension provided should be inserted between dial gauge shaft and probe.
- Measurement from Underside of Cylinder Head (Valve Indentation)
- If the valve indentation cannot be determined, the extension provided should be inserted between dial gauge shaft and probe.
Clean
- Position Measuring Bridge KM-301 on cleaned sealing surface, insert Dial Gauge MKM-571-B under pretension, fasten and adjust dial to Zero.
Inspect
- Position Dial Gauge MKM-571-B with Measuring Bridge KM-301 at valve head and measure indentation of valve.
- The specified valve indentation and the dimensions can be found in the "Technical Data".
- The installation height of the valves should be measured from the upper side of the cylinder head using the depth gauge of a caliper gauge. The measurement is taken from the valve shaft end to the cylinder head.
- The specified valve projection and the dimensions can be found in the "Technical Data".
- Measurements are made using Distance Gauge KM-512.
Install
- If dimension is exceeded, insert new valve and check valve stem projection again. If the valve stem projection is too great despite replacement of the valve, the cylinder head must be replaced.
- The specified valve projection and the dimensions can be found in the "Technical Data".
Cylinder head: flatness check
Turbo (Z20LET) only.
Clean
- Remove gasket residues and clean sealing surfaces.
Inspect
- Cylinder head dismantled.
Measure
- Check length and width of cylinder head sealing surfaces for deformation and diagonals for warpage - use straight edge.
- Caution
- Resurfacing of the cylinder head is not permitted.
- Measure height of cylinder head (sealing surface to sealing surface): dimension - 134 mm.