Diagnostic Prior to Overhaul Saved ~$52,000 by Optimizing the Scope of One Overhaul


Diagnostic Prior to Overhaul Saved ~$52,000 by Optimizing the Scope of One Overhaul



CAT engines


Offshore Jack-Up Rig


Engine Condition Monitoring System


Jack Up Rig Operator In India


  • A Caterpillar 3516B engine was due for the 2nd Top End Overhaul as per the OEM recommendation based on the running hours, but the rig owner had a budget constraint


  • Neptunus has been a preferred partner to this customer for engine maintenance across their multiple rigs
  • Neptunus’ expert advised for pre-overhaul diagnostics using torsional vibration analysis. The objective was to optimize the spare parts list, consumables, manpower and downtime of overhaul
  • Neptunus’ team went onboard & carried out the engine health inspection through the engine condition monitoring tool. .
  • The report data showed issues with the fuel injection quality and the crankshaft main bearings. Other health parameters were within acceptable limits. Based on this data, Neptunus recommended only a Top End Overhaul instead of a 2nd Top End Overhaul
  • The diagnostic findings were reaffirmed when the engine was dismantled for a Top End Overhaul. The hatch marks on the liner & cylinder bore dimensions were observed to be in limits as per the OEM recommendation
  • Engine has been running smoothly for over 6000 hours after the Top End Overhaul


  • Direct savings of ~USD 52,000 due to lesser cost of overhaul. This increased the profitability of the rig.
  • We saved 4 days due to the reduced scope (8 days vs 12 days) thus expediting the rig repair project
  • It allowed the rig and technical teams to focus on the core drilling operations rather than worry about the
    uncertainty of engine reliability.