Checking, cleaning and repairing cylinder head parts [Toyota Corona T190]

1. Clean the piston crowns and the cylinder block surface that mated with the cylinder head.

a) Turning the crankshaft, set the pistons in sequence to TDC. Use a scraper to clean the surfaces of the piston bottoms from carbon deposits.

b) Use a scraper to remove the remaining cylinder head gasket from the cylinder block joint surface.
c) Use compressed air to remove carbon deposits and head gasket residue from surfaces and bolt holes.

Note: When using compressed air, be careful not to get dirt particles into your eyes.

2. Clean the cylinder head.

a) Clean the cylinder head surface from any remaining cylinder head gasket.

Note: Be careful not to damage the cylinder head gasket mating surface.

b) Clean the surfaces of the combustion chambers of the cylinder head with a wire brush, removing any remaining carbon deposits.
c) Clean the cylinder head guide bushing holes with a brush and solvent.

d) Clean the surface of the cylinder head (mating with the cylinder block surface), using a soft brush and solvent.

3. Check the cylinder head.

a) Using a precision ruler and a flat feeler gauge, as shown in the figure, check the non-flatness of the working surfaces of the cylinder head that are mated:

with the surface of the cylinder block.
with the surfaces of the inlet and outlet pipelines.

Maximum permissible surface non-flatness:

gas joint:
- 2S, 2S-T, 3S-GE - 0.20 mm
- 3S-FE, 4S-FE, 4A-FE, 5E-FE, 7A-FE - 0.05 mm
intake manifold mounting:
- 2S, 2S-T, 3S-GE - 0.20 mm
- 3S-FE, 4S-FE — 0.08 mm
- 4A-FE, 7A-FE — 0.10 mm
- 5E-FE — 0.05 mm
exhaust manifold mounting:
- 2C, 2C-T - 0.20 mm
- 3S-FE, 4S-FE — 0.08 mm
- 3S-GE — 0.30 mm
- 4A-FE, 7A-FE — 0.10 mm
- 5E-FE — 0.05 mm

If the value of non-viscosity exceeds the maximum permissible value, replace the cylinder head or grind it.

6) Using penetrating dye, check for cracks in the combustion chambers, intake and exhaust ports and on the gas joint surface. If cracks are present, replace the cylinder head or weld it (with subsequent grinding).

4. Clean the valves.

a) Use a scraper to remove carbon deposits from the valve plate.
b) Use a brush to finally clean the valve.

5. Check the valve stem diameters and the inside diameters of the valve guides.

a) Using a bore gauge, measure the inner diameter of the valve guide bushings.
Inner diameter of the bushing:
- 2S, 2S-T - 8.010-8.030 mm
- 3S-FE, 4S-FE, 4A-FE, 5E-FE, 7A-FE - 6,010-6,030 mm
- 3S-GE — 6.000-6.018 mm

b) Use a micrometer to measure the diameter of the valve stem.
Valve stem diameter:
- inlet valve:
  - 2S, 2S-T - 7.975-7.990 mm
  - 3S-FE, 4S-FE, 4A-FE, 5E-FE and 7A-FE - 5.970-5.985 mm
  - 3S-GE — 5.960-5.975 mm
- exhaust valve:
  - 2S, 2S-T - 7.960-7.975 mm
  - 3S-FE, 4S-FE, 4A-FE, 5E-FE and 7A-FE - 5.965-5.980 mm
  - 3S-GE — 6.955-5.970 mm

c) Using the difference in measurements of the valve stem diameter and the inner diameter of the guide bushing, find the gap between the valve stem and its guide.
- Nominal oil clearance: inlet valve:
  - 2S, 2S-T - 0.020-0.055 mm
  - 3S-FE, 4S-FE, 4A-FE, 5E-FE and 7A-FE - 0.025-0.060 mm
  - 3S-GE — 0.025-0.058 mm
  exhaust valve:
  - 2S.2S-T - 0.035-0.070 mm
  - 3S-FE, 4S-FE, 4A-FE, 5E-FE and 7A-FE - 0.030-0.065 mm
  - 3S-GE — 0.030-0.063 mm
- Maximum oil clearance:
  - inlet valve - 0.08 mm
  - outlet - 0.10 mm

If the clearance is greater than the maximum allowable, replace the valve and guide bushing.

6. If necessary, replace the valve guides.

a) Gradually heat the cylinder head in a water bath to a temperature of 80-100°C.
b) Using a punch and hammer, press out the guide bushing.

c) Use a bore gauge to measure the diameter of the bore for the guide in the cylinder head housing.

d) Select a new size (standard or repair 0.05 mm) outside diameter of the valve guide.

If the diameter of the hole for the guide in the cylinder head housing exceeds:

2C, 2C-T - 13.027 mm
3S-FE, 4S-FE — 11.012 mm
3S-GE - 11.006 mm
4A-FE, 5E-FE, 7A-FE - 11.027 mm

then bore the hole for the guide to the diameter:

2S, 2S-T - 13.050-13.077 mm
3S-FE, 4S-FE - 11.035 - 11.062 mm
3S-GE — 11.038-11.056 mm
4A-FE, 5E-FE and 7A-FE - 11.050-11.077 mm

If the diameter of the hole for the guide in the cylinder head housing exceeds the repair size, replace the cylinder head.

Select the size of the outer diameters of the inlet and outlet valve bushings depending on the diameters of the holes for the guides (see table).

Note: On 2C, 2C-T, 3S-FE, 5E-FE engines, the intake and exhaust valve guides have different sizes.

Guide bushings:

inlet valves:
2C, 2C-T - 46.0 mm
3S-FE, 5E-FE — 38.5 mm

exhaust valves:
2C, 2C-T - 50.0 mm
3S-FE, 5E-FE — 40.5 m

d) Heat the cylinder head in a water bath to a temperature of 80-100°C.
e) Install the valve guide. Using a drift and hammer, install the new valve guide so that it protrudes from the cylinder head by:
- 4A-FE, 7A-FE, 5E-FE - 12.7-13.1 mm
- 2S, 2S-T - 17.3-18.1 mm

g) Using a 6mm reamer (3S-FE, 3S-GE, 4S-FE, 4A-FE, 5E-FE and 7A-FE) or 8 mm (2C, 2C-T), ream the inner hole of the guide to ensure the standard clearance between the guide and the valve stem (see point 5 (c)).

7. Check and grind the valves.

a) Grind the valves until all traces of carbon and scratches are removed.
b) Ensure that the lapped face of the valve forms an angle of 44.5° relative to the plane perpendicular to the axis of the stem.

c) Check the thickness of the valve plate.
Standard plate thickness:
- 3S-FE, 4S-FE, 3S-GE, 4A-FE, 5E-FE, 7A-FE - 0.8-1.2 mm
- 2C, 2C-T
  - inlet valve - 1.41 mm
  - exhaust valve - 1.51 mm
Minimum plate thickness:
- 3S-FE, 4S-FE, 3S-GE, 4A-FE, 5E-FE, 7A-FE - 0.5 mm
- 2C, 2C-T
  - inlet valve - 0.9 mm
  - exhaust valve - 1.0 mm

If the thickness of the cylindrical portion of the disc is less than the minimum allowable value, replace the valve.

d) Check the overall length of the valve
Nominal length:
- Inlet valve:
  - 2C - 105.70 mm
  - 2C-T - 105.50- 05.90 mm
  - 3S-FE - 97.60 mm
  - 4S-FE — 100.60 mm
  - 3S-GE - 105.50 mm
  - 4A-FE, 7A-FE — 87.45 MM
  - 5E-FE — 93.45 mm
- Exhaust valve:
  - 2C - 105.35 mm
  - 2C-T — 105.15-105.55 mm
  - 3S-FE - 98.45 mm
  - 4S-FE — 100.45 mm
  - 3S-GE - 99.55 mm
  - 4A-FE, 7A-FE — 87.84 mm
  - 5E-FE — 93.89 mm
Minimum overall length:
- Inlet valve:
  - 2C, 2C-T - 105.20 mm
  - 3S-FE - 97.10 mm
  - 4S-FE — 100.10 mm
  - 3S-GE - 104.80 mm
  - 4A-FE, 7A-FE — 86.95 mm
  - 5E-FE — 92.95 mm
- Exhaust valve:
  - 2C, 2C-T - 104.85 mm
  - 3S-FE - 98.00 mm
  - 4S-FE — 99.95 MM
  - 3S-GE - 98.85 mm
  - 4A-FE, 7A-FE — 87.35 mm
  - 5E-FE 93.39 mm

If the overall length is less than the minimum allowable length, replace the valve.

d) Check the condition of the end surface of the valves for wear.

If the valve end is worn, regrind the end or replace the valve.

Note: When regrinding, do not allow the overall length of the valve to be reduced beyond its minimum permissible value.

8. Check and clean the valve seats.

a) Using a carbide bur with a 45° cone angle, grind the valve seats, removing a minimum layer of metal only to clean the working chamfers of the seats.

b) Check that the valve is seated correctly in the seat.

Apply a thin layer of white paint to the valve face. Press the valve face against the seat, but do not rotate the valve. Then remove the valve and inspect the seat and valve face.

If paint remains around the entire circumference (360°) of the valve bevel, the valve is concentric. Otherwise, replace the valve.

If the paint shows up all the way around (360°) the valve seat, the valve guide (bushing) and valve seat are concentric. Otherwise, regrind the chamfer.

Make sure that the contact patch is in the middle of the valve working face and has a width of:

3S-FE, 4S-FE, 3S-GE, 4A-FE, 5E-FE, 7A-FE - 1.0-1.4 mm
2C, 2C-T — 1.2-1.6 mm

Otherwise, adjust the chamfer as follows:

If the contact patch is located too high on the valve chamfer, use 30° and 45° cone angle cutters to regrind the seat.

If the contact patch is located too low on the valve chamfer, use 75° and 45° or 60° and 45° cone angle cutters to regrind the seat, as shown in the figure.

3S-GE, 3S-FE, 5E-FE

2C, 2C-T, 4A-FE, 7A-FE, 4S-FE

d) Manually lap the valve and valve seat using abrasive paste.

d) After lapping, clean the valve and valve seat.

9. Check the valve springs.

a) Using a metal square (90°), check the non-perlendicularity of the valve spring as shown in the figure.
The maximum permissible non-perpendicularity is 2.0 mm

b) Use a caliper to measure the free length of the spring in its free state.

Valve spring length:

2G, 2C-T - 47.50 mm
3S-FE, 4S-FE - 40.95-42.00 mm
3S-GE - 44.43 mm
4A-FE, 7A-FE — 38.57 mm
5E-FE — 39.80 mm

If the spring length differs from the nominal length, replace the valve spring.

c) Using a spring tester, measure the force required to compress the spring to its installed length.

Spring elastic force at length:

2S, 2S-T (40.3 mm) - 225-248 N
3S-FE, 4S-FE (34.7 mm) - 164-189 N
3S-GE (34.4 mm) - 201-236 N
4A-FE, 7A-FE (31.7 mm) - 166 N
5E-FE (31.8 mm) - 148-164 N

If the force is outside the specified limits, replace the valve spring.

10. Check the camshafts and bearings.

A. Check the camshaft for bending.

a) Place the camshaft on the prisms.
b) Using a dial indicator, check the runout of the camshaft relative to the center journal.
Maximum runout:
- 3S-FE, 4S-FE, 4A-FE and 5E-FE, 7A-FE - 0.04 mm
- 2S, 2S-T, 3S-GE - 0.06 mm

If the runout exceeds the permissible value, replace the camshaft.

B. Check the camshaft lobe height by measuring it with a micrometer.

2C:
- Nominal cam height:
  - intake - 47.90 mm
  - outlets - 48.35 mm
- Minimum permissible cam height:
  - intake - 47.40 mm
  - exhaust - 47.85 mm
2C-T:
- Nominal cam height:
  - intake - 47.35-47.45 mm
  - outlets - 48.30-48.40 mm
- Minimum permissible cam height:
  - intake - 46.90 mm
  - exhaust - 47.85 mm
3S-FE:
- Height of intake camshaft lobes:
  - nominal - 42.51-42.61 mm
  - minimum allowable - 42.40 mm
- Height of exhaust camshaft lobes:
  - nominal - 40.36-40.46 mm
  - minimum allowable - 40.25 mm
3S-GE:
- Nominal cam height - 41.31-41.41 mm
- Minimum permissible cam height - 41.20 mm
4S-FE:
- Height of intake camshaft lobes:
  - nominal - 34.91-35.01 mm
  - minimum allowable - 34.76 mm
- Height of exhaust camshaft lobes:
  - nominal - 40.36-40.46 mm
  - minimum allowable - 40.25 mm
4A-FE, 7A-FE:
- Height of intake camshaft lobes:
  - nominal - 34.81-34.91 mm
  - minimum allowable - 35.41 mm
- Height of exhaust camshaft lobes:
  - nominal - 41.96-42.06 mm
  - minimum allowable - 41.55 mm
5E-FE:
- Height of intake camshaft lobes:
  - nominal - 41.51-41.61 mm
  - minimum allowable - 41.36 mm
- Height of exhaust camshaft lobes:
  - nominal - 41.31-41.41 mm
  - minimum allowable - 41.16 mm

If the cam lobe height is less than minimum, replace the camshaft.

B. Check the dimensions of the camshaft bearing journals by measuring their diameters with a micrometer.

Diameter of camshaft bearing journals:

3S-GE, 3S-FE 4S-FE - 26.959-26.975 mm
4A-FE, 7A-FE, 5E-FE
- 1st support - 24.949-24.965 mm
- the rest - 22.949-22.965 mm
2S, 2S-T - 27.979-27.995 mm

If the journal diameters are outside the specifications, check the oil clearance between the journal and the bearing.

D. Check the condition of the camshaft bearings for chipping and scratches on their surfaces. If the above defects are present, replace the bearing caps or the cylinder head assembly.

D. (3S-FE, 4S-FE, 3S-GE, 4A-FE.5E-FE, 7A-FE) Check the condition of the camshaft gear leaf spring by measuring the clearance of its lock in a free state.

Clearance:

s and E series engines - 22.5-22.9 mm
a series engines - 17.0-17.6 mm

If the clearance of the lock in the free state is outside the specified limits, replace the pinion leaf spring.

E. Check the radial oil clearance in the camshaft bearings.

a) Clean the working surfaces of the camshaft journals and bearing caps.
b) Place the camshafts in the cylinder head beds.
c) Place a piece of plastic gauge on each camshaft journal.

Note:

(4A-FE, 1A-FE) the arrows on the bearing caps must point towards the front of the engine.

(2C, 2C-T) tighten the bolts in three stages, starting from the inside.

[See the source on the internet resource Toyotaman.ru]

d) Install the bearing caps. Tighten the cap bolts.
Tightening torque:
- s, C series engines - 18 Nm
- engines series A, E - 13 Nm

Note: Do not turn the camshaft.

d) Remove the bearing caps.
e) Measure the width of the flattened plastic gauges at their widest part and calculate the gap.
Radial clearance in camshaft bearings:
- Nominal:
  - motors series A and E - 0.035-0.072 mm
  - c series engines - 0.037-0.073 mm
  - s series engines - 0.025-0.062 mm
- Maximum allowable - 0.1 mm

If the clearance is greater than the maximum allowable, replace the camshaft. If necessary, replace the bearing caps and cylinder head.

g) Remove any remaining plastic gauges.

G. Check the axial clearance of the camshaft.

a) Install the camshaft in the cylinder head bed.
b) Use a dial indicator to measure the axial clearance when moving the camshafts back and forth.

Axial clearance of camshafts:

2C, 2C-T:
- nominal - 0.080-0.18 mm
- maximum allowable - 0.25 mm
3S-FE, 4S-FE:
- Nominal:
  - intake valves - 0.045-0.100 mm
  - exhaust valves - 0.030-0.085 mm
- Maximum allowed:
  - intake valves - 0.12 mm
  - exhaust valves - 0.10 mm
3S-GE:
- nominal - 0.025-0.062 mm
- maximum allowable - 0.08 mm
4A-FE, 7A-FE:
- Nominal:
  - intake valves - 0.030-0.085 mm
  - exhaust valves - 0.035-0.090 mm
- Maximum allowable - 0.11 mm
5E-FE:
- Nominal - 0.045-0.100 mm
- Maximum allowable - 0.12 mm

If the axial clearance is greater than the maximum allowable, replace the camshaft. If necessary, replace the bearing caps and cylinder head.

3. (3S-FE, 4S-FE, 4A-FE, 5E-FE and 7A-FE) Measure the clearance in the camshaft gear engagement.

a) Install both camshafts into the cylinder head without installing the exhaust camshaft drive auxiliary gear.
b) Use a dial indicator to measure the clearance in the gear engagement.
- Nominal clearance - 0.02-0.20 mm
- Maximum gap - 0.30 mm

If the clearance is greater than maximum, replace the camshafts.

11. Check the tappets and tappet bores in the cylinder head housing.

a) Using a bore gauge, measure the diameters of the bores for the tappets in the cylinder head.
The diameter of the bore for the pusher in the cylinder head:
- 2S, 2S-T - 37.960-37.975 mm
- 3S-FE — 31,000-31,018 mm
- 4S-FE — 28,000-28,021 mm
- 3S-GE, 5E-FE - 28,000-28,021 mm
- 4A-FE, 7A-FE - 31,000-31,025 mm

b) Use a micrometer to measure the diameter of the tappet.
Pusher diameter:
- 2S, 2S-T - 37.922-37.932 mm
- 3S-FE, 4A-FE, 7A-FE - 30.966-30.976 mm
- 3S-GE, 4S-FE, 5E-FE - 27.975-27.985 mm

c) Check the oil clearance. Subtract the tappet diameter from the tappet bore diameter in the head housing and determine the clearance.
Clearance between the pusher and the wall of the bore for the pusher: Nominal:
- 4A-FE, 7A-FE - 0.024-0.059 mm
- 2G, 2S-T - 0.028-0.053 MM
- 3S-GE, 3S-FE - 0.024-0.052 mm
- 4S-FE, 5E-FE - 0.015-0.046 mm
Maximum:
- 4A-FE, 7A-FE, 3S-GE3S-FE, 4S-FE - 0.07 mm
- 2S, 2S-T, 5E-FE - 0.10 mm

If the clearance exceeds the maximum allowable, replace the tappet. If necessary, replace the cylinder head.

12. (Except 4A-FE, 7A-FE)Using a precision straight edge and a feeler gauge, inspect the manifold mating surfaces for non-flatness of the mating surfaces.

Maximum non-flatness: