I own a Mitsubishi Pajero 3.8 GLS Petrol.

In December of 2015 it went for its 180 000 km service and within approximately 1 300 kms later it developed a misfire and a sudden clucking sound from the engine. The vehicle was towed to the nearest agent who discovered that the butterfly on the one port had broken up and landed in the engine

On reporting this they also further stated that the bolt for the inlet manifold adjacent to the port where the butterfly broke was missing and which meant that the inlet manifold was not sealed correctly.

Is it possible that the lack of this bolt could lead to air being sucked in to this port resulting in excessive air being brought into this port from a different angle (from the side instead of above) with force causing the butterfly to break up from erratic operation and fall into the engine.

Could anyone confirm this. I have had a positive response from a Mitsubishi Expert but a different opinion from other general technicians.

 

Can you explain what was done during the 180k service?
Fault does sound very suspicious but doubt if you will be able to 'prove' anything regardless of investigation.

jim

 

The normal service which included the changing of the spark plugs and fitting a new cam belt. To change the spark plugs on this engine one has to remove the inlet manifold.