Overhaul of Jenbacher engines, refurbishment of cylinder heads

July 1, 2022by seo es

Within the preventive maintenance tasks of Jenbacher gas engines, one of the most important works to be carried out is the reconditioning of their cylinder heads, overhaul of Jenbacher engines.

The refurbishment of a cylinder head is a type of work that is frequently carried out during the execution of a medium preventive maintenance or a major preventive maintenance (Overhaul). Sometimes, the cylinder heads of Jenbacher engines may need to be overhauled prior to scheduled engine preventative maintenance hours due to unforeseen damages. Therefore, if one or more cylinder heads on an engine are detected or suspected to be in poor condition, it is advisable to replace or overhaul them as soon as possible to reduce the chances of failure or damage to other parts of the engine.


Jenbacher gas engine overhaul

Cylinder heads are parts that normally do not break down on their own if they are frequently controlled and maintained at the hours set by the equipment manufacturer. What does happen most frequently is the wear of its internal components (valves, seats, springs…) derived from the running hours, time, and the accumulated wear after several hours of operation.

Wear can be accelerated if abnormal temperatures are reached in the combustion chamber, water leaks, poor valve adjustment, poor maintenance, use of alternative spare parts or copies when the cylinder head needs to be reconditioned…

In the following lines, we try to summarize the process that our technicians carry out when reconditioning cylinder heads Jenbacher type 3, Jenbacher type 4 and/or Jenbacher type 6:

  1. Once the cylinder heads arrive at RS Motor, our technicians disassemble them to check if their “core” is in good condition or not.
  2. After that, in case all the “head’s core” are in good condition, the next process is to clean all the cylinder heads by introducing them through an ultrasonic cleaning machine. In the event that the “cores” are not good, RS Motor repairs them whenever possible (otherwise the cylinder heads that cannot be recovered are discarded).
  3. Once the cleaning of the cylinder heads is finished, our technicians replace the main wearing parts, such as:


  • Inlet valves.
  • Exhaust valves.
  • Intake valve seats.
  • Exhaust valve seats.
  • Valve guides.
  • O-rings
  • Rotocaps.
  • Valve springs.


  1. Once the assembly of the cylinder heads is finished, a hydraulic test is carried out to verify the absence of leaks.
  2. The last step is to prime and externally paint all cylinder heads before packing them for shipment.


The importance of a good overhaul/reconditioning or refurbishment of cylinder heads (in this case, cylinder heads Jenbacher type 3, Jenbacher type 4 and/or Jenbacher type 6) lies in the fact that these are one of the parts of the engine that break down most frequently due to the stresses those who are subjected. These efforts are derived from the high pressures and temperatures that are reached in them during engine operation.

The reconditioning of the cylinder heads must be carried out when it is detected that the heights of their valves are not adequate, when the manufacturer’s maintenance plan specifies it, or when an anomaly is observed in the operation of the engine that is related to them.

That is why, in order to avoid unscheduled engine shutdowns resulting from poor cylinder head maintenance, there are several factors to take into account:

  • Regular intake and exhaust valve adjustment as specified in the engine manufacturer’s maintenance plan.
  • Installation of quality internal cylinder head components (genuine or OEM). Never use alternative parts or copies.
  • When reconditioning or repairing a cylinder head, it must be taken to a specialist Technical Service that has the specific tools and equipment.
  • Adequate cleaning and decarbonization of cylinder heads when required, allows their useful life to be extended.
  • To avoid unscheduled failures, it is very important to monitor the temperatures of the combustion chambers in order to prevent more important failures that could damage other parts of the engine.