BrianD1973
Seaman Apprentice
- Joined
- Sep 7, 2010
- Messages
- 31
Soooo, check out this video and see what you think this could be? Wondering if someone that has had this issue can easily identify this noise due to the engine and possibly symptoms that may have caused it....
Background - This is a 1986 Mercruiser 170. Have had the boat 34 years (36 years old). Did have the speedi sleeve work done to the camshaft back in 2014 after read info on the common issue and noticed some antifreeze in with the engine oil when checking dipstick... Was investigating antifreeze dripping from engine... I'm suspecting that may have been going on for a little while before noticed/fixed and the results are now starting to appear... The boat only goes out a couple times a year and is stored under cover on land... Thinking crankshaft bearing/s? Recently took to boat mechanic and he had no definite answers but has worked on these engines before. Said engine appears to be harder than normal to turn but other than the sound, runs good and compression checks good... noticed the sound last year and under the engine cover it is barely noticeable... He took drive unit off so do not think the sound is coming from the drive. I thought originally that maybe just the starter pinion gear was rattling against the flywheel. Just happened to stick my head to the back of the engine recently and noticed it's definitely more pronounced with the cover off and ear near the stern. Possibly louder with engine cover on than last year the one time I took it for a weekend trip which maybe caused me to look closer this time?
Related? 2019 heard some starter noises when starting just a couple times. 2020 getting it ready for season and starter definitely broke while attempting. Wrecked the starter, have pictures somewhere... defect in starter or possibly if engine is harder to turn, did that cause the starter issue? Some metallic parts from starter housing, cast aluminum I suspect fell into the flywheel housing. I tried to fish them but yeah, a magnet isn't going to help that situation... I don't think this noise is any of those chipped parts jingling around... definitely sounds like the shaft.... mechanic stated heard a little bit of noise from the front of the engine too.... I have yet to fire up and listen closer there....
Background - This is a 1986 Mercruiser 170. Have had the boat 34 years (36 years old). Did have the speedi sleeve work done to the camshaft back in 2014 after read info on the common issue and noticed some antifreeze in with the engine oil when checking dipstick... Was investigating antifreeze dripping from engine... I'm suspecting that may have been going on for a little while before noticed/fixed and the results are now starting to appear... The boat only goes out a couple times a year and is stored under cover on land... Thinking crankshaft bearing/s? Recently took to boat mechanic and he had no definite answers but has worked on these engines before. Said engine appears to be harder than normal to turn but other than the sound, runs good and compression checks good... noticed the sound last year and under the engine cover it is barely noticeable... He took drive unit off so do not think the sound is coming from the drive. I thought originally that maybe just the starter pinion gear was rattling against the flywheel. Just happened to stick my head to the back of the engine recently and noticed it's definitely more pronounced with the cover off and ear near the stern. Possibly louder with engine cover on than last year the one time I took it for a weekend trip which maybe caused me to look closer this time?
Related? 2019 heard some starter noises when starting just a couple times. 2020 getting it ready for season and starter definitely broke while attempting. Wrecked the starter, have pictures somewhere... defect in starter or possibly if engine is harder to turn, did that cause the starter issue? Some metallic parts from starter housing, cast aluminum I suspect fell into the flywheel housing. I tried to fish them but yeah, a magnet isn't going to help that situation... I don't think this noise is any of those chipped parts jingling around... definitely sounds like the shaft.... mechanic stated heard a little bit of noise from the front of the engine too.... I have yet to fire up and listen closer there....
