Due to the wear of the hinges, the chain stretches over time. In addition to the chain, the sprockets of its drive also wear out. Together, this leads to a decrease in chain tension and, as a result, a shift in the valve timing.
The tension of the chain is adjusted by loosening the cap nut of the plunger tensioner installed under the outlet pipe of the cooling system.
To visually control the operation of the tensioner, we adjust the chain tension with the cylinder head cover removed (see "Cylinder head cover gasket - replacement"). If there is no doubt about the serviceability of the tensioner, the cover does not need to be removed.
Execution sequence
1. We prepare the car for operations (see "Vehicle preparation for maintenance and repair").
2. socket wrench by 13 mm loosen tensioner cap nut ("unloading" tensioner), while his shoe should move, pulling the chain.
3. If the shoe does not move, the reason is the plunger jamming in the collet lock. To fix the problem with a hammer, apply a few light blows to the nut to release the tensioner plunger.
4. Key at 38 mm turn the crankshaft clockwise by 1.5-2 turns and stop it at the moment of greatest resistance to rotation, keeping the shaft from turning in the opposite direction.
5. Tighten the cap nut of the tensioner and install the cylinder head cover.
6. We start the engine and check the operation of the circuit by ear.