Adjusting valve clearances on Vetus M3.10 3 cylinder inboard marine diesel

jameswilson29 said:

Yesterday, I tackled a more challenging maintenance task: adjusting the valve clearances on the Vetus M3.10 inboard marine diesel engine, which the owner's manual recommends every 800 hours. It appeared it had not been done for 18 years, based on the yellow paint on the crankshaft pulley obscuring the marks, which I had to chip off with a screwdriver to locate the marks. The most difficult part was rotating the engine the proper 240 degrees each time to position the cylinder at top dead center for each cylinder. It was interesting to watch the intake and exhaust sequence for the entire engine as it rotates. The engine runs smoother now, especially in idle (less of a rattling sound). Here are my photos and videos:

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Important stuff. If there is not enough clearance the valves do not stay closed long enough to dissipate the heat and can eventually keep the valves from completely closing which will burn them. Timing can also be effected, being slightly retarded. Important stuff, probably ignored by some?

Engine sounds good

Paul T

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jameswilson29 said:

Thanks, I am scrupulous in my engine maintenance.

Yes, I read that in the worst case, without sufficient clearance, the valve may actually contact the piston head. That would probably occur from improper adjustments. With neglect over time, excessive clearance would seem likely to develop. Too much clearance and the timing would be off and the engine would not be operating at optimal performance.

The job was really not that difficult once I started.

As this maintenance is recommended every 800 hours, it is difficult to believe no one adjusted the clearances during the last 18 years. I easily put more than 100 hours on the engine every year.

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