I think my boat is louder now?
 

When we took off from the Marina today I thought our boat sounded slightly louder... I didn't say anything because I knew my wife would get ticked if I mentioned something "could" be broke... as things obviously wear with age.

Unfortunately she noticed it after we got moving. She says " The boat seems really loud, I don't remember it sounding like this?" "Should the motor sound so loud?"

Everything sounds normal per say... but to quote spinal tap, our boat doesn't crank sound out at a 10... it cranks out at 11, 1 sound louder.


This will sound stupid, and I will test it tomorrow... we departed with the convertible top on... this is the first time we've ran it all day. I think the boat was louder because we could hear it due to the lack of wind in our ears? Although it does sound slightly louder at idle.

Another weird thing we noticed.. water spray coming up onto the rear seats and sundeck? I think the convertible top was causing this as well. It only occured at top speed, could this be caused by the air current coming across the convertible top?

Thanks,
Nick


2001 Diablo, 3.0L

Nick

Re: I think my boat is louder now?
 

nglauer,

I don't know about the water spray, but boats do sound loader with their tops up.

Shabah 198SE

Re: I think my boat is louder now?
 

The engine sounded louder because you were sitting in a sound funnel that was pointed toward the back of the boat, which is where the engine is located.

Jim

Re: I think my boat is louder now?
 

Well... we took the boat out today and I can't blame the top. I was really hoping that it just helped to amplify the sound, or make it more noticable. However I don't think that's the problem. I believe i'm noticing some vibration and possibly un-normal mechanical noises.. kinda like clanging/knocking/rough idle noises combined into one (but mild). I did hit a stick back in June/July. It bent my prop slightly, now i'm wondering if it could have done some sort of damage? I replaced the prop the next day (and only logged about 4-5 hours on the mildly bent one) I became paranoid after the incident so I thought I had convinced myself that the boat was making more noise, when it really wasn't. Now i'm wondering if I really did damage something and it's gradually getting worse. It's noticable if the boat is at idle, or running very slow (like in a no wake area). Once I give it some gas it smooths out and sounds fine. So now i'm not sure if the motor is loading up slightly during idle and spark knocking.. or if i'm hearing something in the drivetrain when at lower RPMs? I'd think if something was bent, and out of balance it would amplify at a higher RPM. The only thing I notice when running at a Higher RPM is that the motor seems more loud? I don't have any exhaust leaks.. so it's not the exhaust... Could it be the gasoline? surely a lower octane fuel won't make the motor sound more coarse? and loud?

Perhaps someone with a 3.0 can give me some insight on how their boat idles, and sounds at higher RPMS?

Thanks again guys, I really appreciate the help.

p.s. spotted two other Mariah's on the water today. I haven't seen another Mariah around here until now. I think they were both Barchetta's (not sure how you spell it). One is maroon the other one black, look like mid-late 90's models and both were really nice looking from what I could tell. Wish I could have stopped to talk to the owners, they both gave us the thumbs up when they saw we had a Mariah as well. I'm hoping the next time out I can catch one or both of them and get some information about their boats. Perhaps the owners are already on here... if not I'll let them know about the forum.

Re: I think my boat is louder now?
 

I grounded my 182 Shabah on a sand bar in the mississippi last weekend while going about 20mph.. One channel marker was missing, I was on the wrong side & my lowrance depth finder seems to have a blinking issue. After shoving off the sand in 18" of water I kept thinking there was a strange sound coming from the rear of the boat, I went straight to the ramp and pulled it out to inspect.. I found nothing visually wrong with the outdrive or the prop. I am thinking it was just all in my head!

My 3.0 is pretty loud for the little engine that it is, I've had people in other boats & on shore tell me that it certainly doesn't sound like a 4 cylinder when up on plane. My exhaust bellow is till attached and not torn, the sucker has always been this loud. Mine also has a dieseling issue when I turn it off, higher octane fuel makes no difference, I've just started putting it in gear before shutting it off to prevent it. I may go with 1 range colder on the spark plugs.

Re: I think my boat is louder now?
 

I'm wondering if it's all in my head as well. I'm a first time boat owner, so everything makes me nervous lol. I agree..the 3.0L doesn't sound like a 4cyl when up on plane, or really when idling. I did double check everything and if something is wrong it's completely internal. I did notice some oil around my pvc valve on the valve cover... it wasn't there the last time we took it out, but it was a very light amount (maybe a few drops). I suppose it's from the way I drive the boat compared to the PO. I figure the fluids splash around slightly more with me behind the wheel. I'm thinking about pulling the plugs and checking them this weekend, I think my boat runs a little rich anyways. Perhaps part of the problem i'm having is the fuel mixture. It's alot easier to tell a mild miss on a car.. but I figure it's pretty hard to tell if your getting spark knock on a boat.


Thanks again, I'll keep an eye on mine.... hopefully it's all in my head :)

Nick

Re: I think my boat is louder now?
 

I've noticed a little oily dampness on my valve cover as well, not really any drops, just an oily residue on the valve cover and the side of the head.. I suspect it's from the crappy PCV system that really has no suction since the plastic "hose" just clips to the side of the spark arrestor.. Crankcase pressure can get pretty high when an engine is spinning 3,000+rpm for extended periods of time, I can't see why mercruiser didn't do more about it. I may fashion up a better PCV system before next season.

When the engine is warmed up mine has a little rocker arm chatter at idle, but it's got plenty of oil pressure, must just be the nature of these little 3.0s. Sucker runs great though, and seems to sip gas.:wink_thumbup:

Re: I think my boat is louder now?
 

Mine is more of a residue as well... I was also shocked that the PVC valve was setup like it is. I'm thinking a regular valve breather would work better. I have a few from my old Camaro, perhaps one of those will work. Mine also has a little valve chatter at idle, but carries good oil pressure.

I seem to be getting good gas mileage, maybe a little less now that i'm running a 14x17 3 blade michigan aluminum prop. What prop are you running on your boat? I wonder if the hull on the 182 Shabah is similar or the same as my 180 Diablo?

Do you pull any skiers or tubes behind your boat? have you added a hydrofoil or smart tabs? curious if you've done anything to yours.. before I start my christmas list lol.

Thanks again,
Nick

Re: I think my boat is louder now?
 

I'm running a 14.25x21 Michigan 3 blade aluminum prop.

I don't know for sure if the hulls are the same, but I wouldn't imagine they had two different hull molds for an 18' boat.

I haven't pulled any skiers, I've pulled a 3 person hot dog with a two 9 year olds on it and I had my father fling me around on a tube, the boat didn't seem to have any issues with those loads.

I don't have a hydrofoil or smart tabs.. I wouldn't be able to do the tabs due to my frequent beaching, I'd be afraid I'd rip them off when I shove the boat off the beach. I haven't made any modifications outside of adding some rear speakers, the rest was just repairs/maintenance. I replaced a broken stereo antenna, fixed the grounding issue that was causing all my dash gauges to act erratic, cleaned up and buffed the hull, replaced the water impeller, recarpeted the inner fender boards on the prestige trailer, new trailer tires, etc. I really need to replace/upgrade the stereo, the cd player doesn't work and there isn't an mp3/aux input.. That's going on the christmas list. It's a 1998 and never had the belts replaced and has only had 1 tuneup in those 12 years, so that'll all be on my dewinterizing list for next year.

Re: I think my boat is louder now?
 

I notice sound differences in my boat all of the time. It can drive you nuts.

I've found most are caused by the top up or down, wind direction, who's sitting where in the boat, are you sitting or standing at the helm, and so on.

But when it sounds the least bit different, I always take notice. It's the sign of being a responsible boat owner!! :wink_thumbup: