Corrosion damage of cast water gallery walls adjacent to valve seats was discovered after several 137 hp 6 cylinder diesel engines mounted onto portable drilling rigs started to run roughly and the cooling systems were over pressurizing.
Because the engines were still under warrantee, maintenance Staff conferred with the OEM agents as to possible causes. However according to both the agent and the OEM, due to lack of other similar feed back from the field, the European based OEM could not assist, meaning the operator was faced with trying to sort out the problem.
Due to the workload commitment of the rigs and the uncertainty of the repairs plus the time and expense involved, the operator was referred to Visiscope for professional assistance. With in a few hours the Visiscope technician was “on the job” ready to undertake NDT of a representative of the faulty engines. Using both the boroscope & fibre scope units which were aided by viewing monitors.
Several combustion Chambers highlighted evidence of possible coolant erosion damage of the cylinder Head adjacent to the valve seats. Further investigation via the coolant jacket side of the cylinder head confirmed the seriousness of the problem. Fortunately the Operator was then able to present the OEM recorded video evidence of the failures; accordingly the OEM accepted full liability, resulting in new components and repairs at no cost to the operator.
