New to v-drives, loud buzzing noise while cruising

[hcooperrn]

Hi everybody, my wife and I just picked up a new-to-us 2003 22V and can't wait to dive in. We had an I/O before we had our kids, and now that they can stand on their own, we're getting back into boating to try surfing. It has the Merc 350 Ski Sports with just overt 600 hours, Velvet Drive 1:1 transmission, Walter 1.46:1 v-drive, 537 propeller.

I've spent hours now reading through this site, and since our boat is a bit rough around the edges, I already have a nice, long to-do list ahead of me

We took it out over the weekend to practice driving before our lakes get busy, and I do have a question that I couldn't quite find a description for; probably because I'm just not that familiar yet with what I have.

At cruising, most noticeable above 20mph or so, there's a fairly loud buzzing-type sound, not quite sure how to describe it. It isn't quite as harsh as bare gears grinding, yet still very noticeable, not smooth running noises for sure. Honestly, the best description that I would have is that it sounds like a muffled piston-plane engine. It doesn't really change with turns, only gets quiet and goes away when slowing down. I don't have the feeling of "peeling out", so I don't think it's cavitation, if that's a good description of that. No real vibration feel in the boat, though the sound definitely has a vibration aspect to it, if I'm making sense at all.

I bought it from a local, well-known dealer; during the test drive, he said that it was a normal sound? It obviously isn't so terrible that it turned me off from the deal, I just need to know what to look out for. The PO did some creative wiring with the Taps that I get to sort out; otherwise, the boat seems pretty straightforward, just rough around the edges, it hasn't been babied.

I've checked all the fluids -- levels all good, clear fluid, correct color, no foam or milk. I have not checked alignment yet; that's on the list for this weekend. The prop looks good -- if it has been repaired, then the repair matched the machining marks perfectly. Fins are straight; fins, prop shaft, and rudder are all in a nice, straight line. The engine seems to run smooth, it isn't a Cadillac but not missing or loping either; it has a decent amount of noise around the impeller housing; I'm assuming that's normal though.

What else should I be checking/concerned about, or is this normal? Are v-drives, especially 12 year old v-drives, just noisy in the drive-train?

Thanks in advance -- once I get this sorted out, I've got a small list of questions that I haven't been able to answer through searches, but I won't mix the threads.

[gwhite94]

I would say that most v-drives and direct drives I have more of a whine sound while underway. But if you are feeling a vibration as well that could cause some concern. Welcome to the site and am sure others will weigh in with some more insight. Post up some pics of your boat and where do your ride in the area?

[boatwakes]

Next opportunity you get, determine if it's engine related or driveline related and listen to everything with the engine cover off and the seat removed. Locate the general area and zoom in on the noise when you find it. Your description sounds like an exhaust manifold leak to be honest but let us know.

[hcooperrn]

boatwakes -- Thanks, I'll give that a try, may be able to run it this weekend. It roughly sounded like is was coming from the vdrive area; I'll remove everything so I can be more precise.

gwhite94 -- Thanks for the help, it's not quite a whine; I wouldn't be surprised to hear something like a timing gear sound, but it isn't that high in pitch. Not much vibration, if there is, it's weak. If it isn't busy I'll go to Chatfield, but usually during the summer weekends we head up to Jackson lake; we've been blown off the water a few afternoons before but it's worth it to have our own space on the lake during the morning. Will get some pics taken this weekend after I finish waxing it.

[Thegerman618]

I am with BoatWakes, reason I say this I had to do this on my boat. Mine was the exhaust muffler rattling off the hull, I wouldn't really notice it at idle unless I was listening for it, but at speed yes it can sound like piston airplane (yes I am pilot so I can attest). I say this assuming you have mufflers on your boat, if your the wet exhaust hosing then this is not applicable to you and check all the clamps in your exhaust to ensure you don't have a leak, any water in the bilge after driving around?

[hcooperrn]

Thanks for that, I do have mufflers so I'll pay close attention, that could make sense. Just a few random drops here and there in the bilge after we were cruising around for about an hour, nothing that I could even trace a drip to.

[Thegerman618]

Okay, just a little water in the bilge is OK that is probably from your shaft seal they drip about 1 drop a second or so. Depending how OCD you are you can fix that with a PSS dripless shaft seal in the future, but they are more of a like to have then a must have. Keep us in the loop, I am sure everyone will help out as they can.
Also the way I fixed mine from rattling, I bought PVC the same diameter as the exhaust muffler and wedged it under the exhaust to keep it from rattling just measured the distance from the hull to the exhaust and bough the same wall thickness on the PCV. Cut it in half long ways so it just slides under, the muffles don't get hot so you don't have to worry about melting anything. Ran it all last season no issues.

[IDBoating]

I once had a "sound" in my engine compartment. Two things helped identify it: A mechanic's stethoscope (cheap at Harbor Freight), and recording the sound on my cellphone so I could play it for others who had more experience than me. You could record the sound and upload the MP3 to this site so we could hear it for ourselves. Then, when you're going to start removing engine covers and such, have the stethoscope handy so you can narrow in on where the sound is coming from.

Update: These are $3.99 at Harbor Freight:

[hcooperrn]

Thanks for the help, I have one of those stethoscopes, I will try to isolate the noise from the engine to either the impeller or one of the pulleys, it just isn't as smooth and quiet even during idle up there as I'm used to with my car engines (I've built race cars/motorcycles for years, I tend to be picky about my smooth idle). I'm sure a full tune-up will help that end of things, though I don't think those would be the cause of my louder noise during cruise, the source is definitely lower in the boat and I'll pinpoint that with the seat/covers off.

Thanks for the tip with the PVC pipe -- that was going to be my next question; what to do about it if that's the cause. I'll measure before I head out next and have it ready, if that sounds like it, I can fix and confirm.

Will keep this post up to date (can't stand open-ended forum posts, it doesn't help the next person searching!), they dropped the temps in our forecast, so now I get to run out tonight and drain it, and we'll have to see if I can talk my wife into going out this weekend with the colder temps.

[Heff]

Have you been able to narrow anything down yet? The wife and I just picked up a new to us 24V and having similar thoughts. I had never drive an inboard prior, and thought it was a vibration the first time from about 3500-4000rpm. The 2nd time it seemed noticeably less to the both of us, so we didn't know what to think. One blade on the prop was a bit warped, so I put a new ACME on and just took it out for about 10min. After this time, I'm starting to think it's just resonance, and lack of give in the drive train compared to an OB or IO. I need to check alignment through the strut etc., and plugs/wires. V-Drive oil and transmission fluid have been changed.

Hopefully we're both just sensitive new owners...

[hcooperrn]

Still haven't made it out on the water. I've given the engine a good tune up, the belt was shredding for starters. The alternator looks new, so I'm guessing they did t check for coplaner pulleys. Took the spaces out and things look better.

Also gave it new plugs, cap, rotor, impeller, and IAC muffler. In the driveway, it's nice, smooth, and quiet as it should be.

The mufflers at kind of close to the engine mounts, so when I get out in the water, I'll be checking for the source, paying attention to the mufflers, the shaft seal(still has the dry version on it), and anything else that could buzz.

Forecast for snow tonight...just got back from draining it again...

[Thegerman618]

Sounds like you got all the major annual maint. stuff done. One last thing, if you haven't already is to check the prop and tracking fins any little bend or tweek in the prop will cause some vibration. Just a precaution, I always to a once over on the prop before I drop it in the water, one rock at the right spot will sometimes put a little ding in the prop. HCOOP-HEFF you guys are good to catch that stuff, some people just assume (it will be fine). Best thing is to know your boats little sounds/noises/vibrations. They all respond differently, that way when something new pops up you will notice it. I was the same way when I bought my boat, every stupid noise, buzz, vibration I was posting a question. That's whats great about the forum, even if the advice you get to fix a problem is not the problem at all, you still learn that if something pops up in the future you know to look there, or if you beat us to a posts you can answer the questions as well. GOOD LUCK and HAPPY BOATING

[hcooperrn]

Yep, I've taken a good look at those, and while I didn't get a long straight-edge out, everything is nice and aligned as well as I can see. Prop looks practically new, no dents, bends or nicks. It's frustrating that we got the boat and haven't even been able to take it out yet, looks like Memorial Day is the next chance now.

[River Runner]

Trans has beveled gears for fwd....and straight gears for reverse.

Only noise you should be hearing from tranny is during reverse....this is normal.

Any excessive noise from transmission during fwd operation is a problem.

[Heff]

It appears that we have ridden ourselves of the resonance sound/vibration in ours. After changing to a new prop, swapping fluid in v-drive and transmission, we no longer hear anything in the 3500-4000 rpm range. Next up is motor oil and filter, impeller, spark plugs, air filter, and fuel separator.

We had a bit of a wave in one blade on our prop. Our neighbor (JLG) noticed it, and I wouldn't have thought anything of it on an I/O or OB. Hard saying for sure, since he brought over his pump, and we did the v-drive and trans at the same time.