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Autopapyrus · Lada Granta 1.6 8V VAZ-21116 (2012)
https://autopapyrus.com/guides/lada/granta/valve-lapping/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Lada Granta 1.6 8V VAZ-21116 (2012): Valve Lapping

Lapping is needed when the valves no longer seal properly: loss of compression, misfire on a cold engine, rough idle. On the 21116 engine it means removing the cylinder head. This is an interference engine (the valves bend if the timing belt breaks), so mark and set all timing marks with extra care.

Difficulty: Hard Time: 1-2 days (cylinder head removal, inspection, lapping, reassembly and valve clearance adjustment) Steps: 17

Parts

10
№Part
01 Engine gasket set (head gasket, valve cover gasket, seals)
02 Cylinder head bolts (new)set
03 Valve stem seals (set)8 pcs
04 Timing belt with rollersset
05 Coolant
06 Engine oil
07 Oil filter
08 Valve keepersif worn
09 Valve springsif worn
10 Valvesif worn

Tools

11
  • socket and wrench set
  • torque wrench
  • valve spring compressor
  • drill or low-speed screwdriver
  • lapping compound (coarse and fine)
  • suction cup or rubber hose lapping tool
  • feeler gauge set
  • caliper
  • marker
  • kerosene or parts cleaner
  • cylinder head bolt socket

Step by step

17 steps
  1. Before disassembly, check the compression in each cylinder and make sure the cause is the valves and not the rings. If compression barely rises after adding 15-20 mL (0.5-0.7 fl oz) of oil to the cylinder, the valves or head gasket are at fault. Start work on a cold engine.
  2. Disconnect the negative battery terminal. Drain the coolant from the block and radiator. Remove the air filter housing with its ducts, then disconnect the throttle cable, sensor connectors, ventilation hoses, and fuel lines (relieve the pressure in the fuel rail first).
  3. Remove the downpipe or disconnect the exhaust manifold from the pipe, then remove the intake receiver with the fuel rail and injectors, and the exhaust manifold. Remove the valve cover and the timing belt guard.
  4. Set piston No. 1 to TDC using the marks on the camshaft pulley and the crankshaft pulley (the marks on the pulley and the belt cover must line up). Loosen the tensioner roller and remove the timing belt. Do not turn the crankshaft or camshaft with the belt removed.
  5. Remove the camshaft pulley, the camshaft bearing housing with its caps (the caps are marked; keep their order and orientation), the camshaft, and the valve rocker arms. Lay out the rocker arms, adjusting bolts, and supports strictly in order. They have worn in as matched pairs and must go back in their original positions.
  6. Loosen the cylinder head bolts evenly, in the reverse of the tightening sequence (from the edges toward the center, in several passes). Remove the head. If it is stuck, do not pry on the mating surface; rock it gently or tap it loose with a rubber mallet. Replace the gasket with a new one.
  7. Place the head on a clean bench with the combustion chambers facing up. Clean the carbon from the chambers and inspect the seats and valve heads. Only minor pitting and ring-shaped wear are acceptable. Deep pits, burned valve edges, cracks, and bent stems mean valve replacement or seat machining, not lapping.
  8. Compress the valve springs and remove the keepers. Number each valve together with its springs and retainers by cylinder, then pull the valves out. Remove the old valve stem seals (always replace them with new ones when lapping). Check the stem play in the guide: noticeable side play means worn guides, and lapping will not fix that.
  9. Apply a thin layer of coarse lapping compound to the valve face. Seat the valve in its own seat, fit a rubber hose or suction cup on the stem, and rotate it back and forth (about half a turn each way) with light tapping, lifting the valve periodically to redistribute the compound. Repeat until an even matte band without pits appears on the valve face and seat (usually 5-10 minutes per valve).
  10. Wash off the coarse compound, apply fine compound, and repeat the lapping for a shorter time (1-2 minutes) until you get an even matte-gray ring without shiny spots. Do not lap longer than necessary, or the seat will sink and the valve will sit too deep.
  11. Clean the seats and valves of compound with kerosene or parts cleaner, and rinse the ports and valve guide wells. Check the lapping quality: draw several pencil lines across the valve face (the lines should wear off when the valve is rotated in the seat), or pour kerosene into the port with the valves installed and make sure it does not seep into the chamber for several minutes.
  12. Lubricate the stems with engine oil and install each valve in its own position. Fit the new valve stem seals (carefully, through the protective sleeve so the stem end does not tear them), then the springs and retainers, and compress the springs to install the keepers. Make sure the keepers have seated in the grooves (tap the valve tip lightly with a hammer through a drift).
  13. Wipe the block and head surfaces and make sure they are clean, dry, and flat (check the head for warpage with a straightedge). Install the new gasket, the head, and the new head bolts. Tighten strictly following the manufacturer's sequence, from the center outward in several passes. As a guide: initial tightening about 20 N·m (15 lb-ft), then 68-85 N·m (50-63 lb-ft), then turn an additional 90° and another 90° (verify the exact values and sequence against the service manual for the 21116 engine).
  14. Install the rocker arms and camshaft in their original positions, tighten the bearing housing caps (torque around 15-20 N·m (11-15 lb-ft), per the service manual), then fit the camshaft pulley and the timing belt according to the marks. Tension the belt to specification using the tensioner or roller, turn the crankshaft two full revolutions by hand, and make sure the marks line up again and there is no resistance.
  15. Adjust the valve clearances on a cold engine. As a guide, about 0.2 mm for intake and 0.35 mm for exhaust (measured with a feeler gauge between the rocker arm and the camshaft lobe, with the lobe's base circle facing the rocker arm). Adjust with the bolt and locknut on the rocker arm. Verify the values against the engine service manual.
  16. Install the valve cover with a new gasket (tighten to about 5-8 N·m (4-6 lb-ft)), then the intake and exhaust manifolds with new gaskets. Reconnect all hoses and connectors, refill the coolant, and bleed air from the cooling system. Change the oil and filter.
  17. Start the engine, warm it up to operating temperature, and check for leaks, seepage, and unusual noises. After 500-1,000 km, check the oil and coolant levels and, if necessary, recheck the valve clearances.

Common mistakes and warnings

  • The 21116 is an interference engine: if the timing marks are misaligned or the belt breaks, the pistons will hit the valves, so check that the marks line up before every belt installation and again after turning the engine two revolutions
  • Cylinder head bolts are torque-to-yield and must never be reused
  • If you have no experience working on a cylinder head, leave disassembly, inspection, and seat machining to a repair shop