No oil pressure observed at startup of Detroit 16V71 engine

What happened

Technicians had commissioned a couple of Detroit 16V71 engines, along with their gearboxes. At the time of commissioning a zero oil pressure from one of the engines was observed. A commissioning engineer was paying close attention at the time of the test and was able to shut the engine down within 20 seconds. The engine was fully overhauled and bench tested the engines, all witnessed by DNV. It had been sat dockside for a few months since the overhaul but was well protected. It's vital to ensure that critical performance information is constantly monitored when starting an engine, to ensure everything is as it should be. The first thing to check was the gauge, to make sure it was giving reliable information. To do this, it was swapped over from the other engine. The engine was restarted, but no change, so again it was quickly shut down and the feed pipe to the gauge checked for blockages. None were found. Looking back over the oil system from the pump, it went through the filters, then cooler, so the next step was to remove the oil filters. Checking them, there was evidence of oil passing through, but not as much as expected. Refitting the filters and restarting the engine, the pressure went straight up to 40 PSI.

Root cause

There was an air in the system that was released during the removal of the filters. When starting an engine, make sure there is no air in the lube oil system, because if this engine had been run without oil circulating, it would have seized up, causing significant issues.

Submitted by Bartech Marine Engineering