YeOldeStonecat
Active Member
- Jun 10, 2018
- 332
- Boat Info
- '97 300 DA "Me-Shell"
- Engines
- Twin 5.7 V-Drive
So as I'm tweaking things on the second summer of our "new to us" boat (the '97 300DA)....I'm getting bothered by what I think is high oil consumption on the starboard engine.
Brief history/background.
*Purchased boat Spring 2018.
*Last summer, and this summer, the starboard engine is still thirsty for oil. Last year I noted the original owner has used 10-40 oil. I changed oil twice last year with 25-40 Quicksilver oil...hoping the thirst for oil would slow down with the proper thicker stuff. It didn't.
Plus look OK. No drips in the bilge, it's not a leak.
Engine hours, ~570 port, ~660 starboard. 5.7 260 hp Mercruisers.
I topped off oil before a trip to Greenport LI a few weeks ago, when we returned, the ~4 hour cruise consumed 1/2 qt of oil in the starboard engine. Probably not even an 1/8th of a qt in the port engine. My cruising speed for most of it was 3300-3400 rpm. I rarely take her about 4k rpm...probably twice this summer, and not for long.
Engine temps decent...165-170.
I have read that PCV valves can affect oil consumption. I "think" mine are just elbows there with a hose to the flame arrest/air intake...but will check.
She gives nothing visible for exhaust...no smoke.
No oil sheen in exhaust water existing.
There is a very slight blackening around the starboard engines above water exhaust exit...very slight, compared to the port side which is nice 'n clean white.
I'm fearing valve seats I suppose? Not sure what a top end job runs. ugh.
Until THEN..has anyone in a similar situation found some relief in going with a thick straight weight? We don't run her in cold weather, she's not year round up there...up on the hard during winter.
Brief history/background.
*Purchased boat Spring 2018.
*Last summer, and this summer, the starboard engine is still thirsty for oil. Last year I noted the original owner has used 10-40 oil. I changed oil twice last year with 25-40 Quicksilver oil...hoping the thirst for oil would slow down with the proper thicker stuff. It didn't.
Plus look OK. No drips in the bilge, it's not a leak.
Engine hours, ~570 port, ~660 starboard. 5.7 260 hp Mercruisers.
I topped off oil before a trip to Greenport LI a few weeks ago, when we returned, the ~4 hour cruise consumed 1/2 qt of oil in the starboard engine. Probably not even an 1/8th of a qt in the port engine. My cruising speed for most of it was 3300-3400 rpm. I rarely take her about 4k rpm...probably twice this summer, and not for long.
Engine temps decent...165-170.
I have read that PCV valves can affect oil consumption. I "think" mine are just elbows there with a hose to the flame arrest/air intake...but will check.
She gives nothing visible for exhaust...no smoke.
No oil sheen in exhaust water existing.
There is a very slight blackening around the starboard engines above water exhaust exit...very slight, compared to the port side which is nice 'n clean white.
I'm fearing valve seats I suppose? Not sure what a top end job runs. ugh.
Until THEN..has anyone in a similar situation found some relief in going with a thick straight weight? We don't run her in cold weather, she's not year round up there...up on the hard during winter.
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