I sail 1988 Catalina 30, Universal M18 Diesel (14 Hp) We have noticed an increase in Motor Noise. Motor hour meter shows 370 hours. We have just owned RECESS since since spring of 2007. We changed oil and fuel filters and have put 55 hours on motor. We have experienced no trouble except the motor has definitely gotten louder. From condition of boat in general, we have no reason to doubt the hours. Motor starts quickly. No smoke, no oil usage, no fluid or oil leaks, runs cool,. starts easily whether cold or hot. warms to about 150 to 165 degrees,. motor doesn't appear to have ever had a wrench on her, paint is like new. When standing on the dock, we could hardly hear her run. Lately, she sounds like a gremlin is down below and hitting the hull with a 2 X 4. On the lake, we hardly noticed the noise while in the cockpit, how it is hard to visit with others. It is 19 years old and I am wondering if it could be the water/muffler? We have about 30-40 cruisers on our lake and no-one seems to know much about diesels. We run her 1600-1800 rpms to 2200-2300 rpms. She seems to feel best about 1900 to 2000. I could use some advise. What could it likely be besides water/muffler?
Diesel motor Noise
- Thread starter Digger
- Start date
- Status
I've a universal 16 hp
And it's noisy.. sounds like jack hammering at certain low rpms.. All the diesel "experts" say its because it's a 2 cylinder engine. We had some problems with the raw water pump not moving enough water which turns out the pump cover plate was loose and had a thick gasket. It never over heated though! It is quieter now with more water in the muffler system. I think Catalina mufflers are pretty large and seem to go bad quite often. so I'd ck your pump. It's most likely an overdorfer 202m-7 Although there are many Universal engines with sherwood pumps out there too. good luck Denise
And it's noisy.. sounds like jack hammering at certain low rpms.. All the diesel "experts" say its because it's a 2 cylinder engine. We had some problems with the raw water pump not moving enough water which turns out the pump cover plate was loose and had a thick gasket. It never over heated though! It is quieter now with more water in the muffler system. I think Catalina mufflers are pretty large and seem to go bad quite often. so I'd ck your pump. It's most likely an overdorfer 202m-7 Although there are many Universal engines with sherwood pumps out there too. good luck Denise
noise sources
Dave It goes without saying you won't be sneeking up on anybody with that engine - they are inherently noisy typically from the exhause due to the fact it is a 2 cylinder. Having said that, any increase in noise level could be due to engine vibration - check the motor mounts (most likely source from your description of the vibration); exhause leak - check waterlift muffler or exhaust hose; valves needing adjustment; exhaust elbow leak (not likely or you'd notice it. If you don't figure it out, come back with a better desc of where the noise appears to originate
Dave It goes without saying you won't be sneeking up on anybody with that engine - they are inherently noisy typically from the exhause due to the fact it is a 2 cylinder. Having said that, any increase in noise level could be due to engine vibration - check the motor mounts (most likely source from your description of the vibration); exhause leak - check waterlift muffler or exhaust hose; valves needing adjustment; exhaust elbow leak (not likely or you'd notice it. If you don't figure it out, come back with a better desc of where the noise appears to originate
After 50 hours you could change the oil
and oil filter and see if that mellow the sound out a bit. Old engines like to have their oil changed often and 50 hours is mentioned in Nigel Caulder's "Boatowners Mechanical & Electrical Manual" as a good changing point for diesels. You can also put in a cup or so of MarvelMystery Oil (3W) with the fresh oil. If it still seems loud then I would check everything else that has been mentioned (engine mounts etc). Make sure your new oil is made for compression engines. Most oils are manufactured for spark ignition engines (cars) and carry an API code of Sx while those made for diesels (compression) carry an API code of Cx (CC, CE, CF-4 etc). This designation will be on the label somewhere. My boat has an atomic 4 gas engine that still runs pretty quiet (after 38 years) compared to most diesels. I was on a friends boat recently which has a Universal 5430 or such 3 cylinder engine which gives off much more vibration than my A4 does but I still like diesel engines even if they vibrate a bit. Good luck.
and oil filter and see if that mellow the sound out a bit. Old engines like to have their oil changed often and 50 hours is mentioned in Nigel Caulder's "Boatowners Mechanical & Electrical Manual" as a good changing point for diesels. You can also put in a cup or so of MarvelMystery Oil (3W) with the fresh oil. If it still seems loud then I would check everything else that has been mentioned (engine mounts etc). Make sure your new oil is made for compression engines. Most oils are manufactured for spark ignition engines (cars) and carry an API code of Sx while those made for diesels (compression) carry an API code of Cx (CC, CE, CF-4 etc). This designation will be on the label somewhere. My boat has an atomic 4 gas engine that still runs pretty quiet (after 38 years) compared to most diesels. I was on a friends boat recently which has a Universal 5430 or such 3 cylinder engine which gives off much more vibration than my A4 does but I still like diesel engines even if they vibrate a bit. Good luck.
Motor mounts
Already mentioned, but I would start there as they are easy to check. i would also sit beleow with the engine running and the engine covers off and just watch and listen for a few minutes. You may see the problem or at least be able to narrow down where it is coming from. I doubt an oil change is going to make your engine quieter.
Already mentioned, but I would start there as they are easy to check. i would also sit beleow with the engine running and the engine covers off and just watch and listen for a few minutes. You may see the problem or at least be able to narrow down where it is coming from. I doubt an oil change is going to make your engine quieter.
I agree with motor mounts
Is it louder when your in gear? When I bought my boat and was moving it to its new home I noticed a loud noise that did sound like a bearing or a knock and investigated it while under way and figured out that it was coming from the drive tran, thougt for sure I had a bad bearing in the tranny but after a lot of research (and not able to remove the tranny but thats another story) it was the alignment of the engine and some soft motor mounts. I replaced the mounts,had the prop balanced, checked the shaft and spent a lot of time aligning the engine prop flange to specs which are within 002 or 004 of an inch and now all is quiet.
Is it louder when your in gear? When I bought my boat and was moving it to its new home I noticed a loud noise that did sound like a bearing or a knock and investigated it while under way and figured out that it was coming from the drive tran, thougt for sure I had a bad bearing in the tranny but after a lot of research (and not able to remove the tranny but thats another story) it was the alignment of the engine and some soft motor mounts. I replaced the mounts,had the prop balanced, checked the shaft and spent a lot of time aligning the engine prop flange to specs which are within 002 or 004 of an inch and now all is quiet.
Check the alternator belt
Check the alternator belt. A possible source of noise is a loose, slapping alternator belt.
Check the alternator belt. A possible source of noise is a loose, slapping alternator belt.
mounts ...
If your mounts are worn or saging, then this could cause the shaft to knock against the bottom of the log. I had this problem on my '87 Legend 35. It was particularly bad at low rpms and especially when slowing down quickly. In addition to proper shaft alignment, the shaft should be centered fairly accuratly in the shaft log hole. For me, I had to raise the engine about 3/16" to account for the mount sag. I really need new mounts. Chris
If your mounts are worn or saging, then this could cause the shaft to knock against the bottom of the log. I had this problem on my '87 Legend 35. It was particularly bad at low rpms and especially when slowing down quickly. In addition to proper shaft alignment, the shaft should be centered fairly accuratly in the shaft log hole. For me, I had to raise the engine about 3/16" to account for the mount sag. I really need new mounts. Chris
- Status