Cylinder head bolts: common defects and their signs

1. Damaging of thread or bolt break.
   • Cooling liquid consumption increases.
   • The engine looses power.
   • Cooling liquid pressure increases.
   • Emulsion appears on antifreeze surface due to ingress of oil into the expansion tank.
2. Wear-out.
   • Oil leakages appear on the engine or in the areas of cylinder head and cylinder block connection.
   • Engine operation is unstable.
   • Engine temperature increases.
   • Fuel consumption increases.

How to replace cylinder head bolts?

Service life of the cylinder head bolts depends on compliance with the tightening force requirements. For each car engine model manufacturer sets corresponding tightening torque. The broken bolt is irreparable, so when the defects noted above appear, it should be replaced.

Specific skills and equipment are necessary for component replacement, so this job should be entrusted to service station specialists.

Replacement of the cylinder head gaskets kit is performed together with car bolts replacement. Moreover, after 1 000 km after these elements replacement, specialists recommend to perform adjustment of bolts tightening torque, which is also performed at a service station.