Started boat today, i have a hiss sound coming from the motor? normal?

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
So i hooked up the muffs and started the boat today and i have a hiss like sound coming from the engine, its sounds like its under the carb. Is this normal?
sounds more like a vaccum, but the engine sounds good,
07 merc 3.0 alpha 1
 

WizeOne

Commander
Joined
Mar 23, 2008
Messages
2,097
Re: Started boat today, i have a hiss sound coming from the motor? normal?

Do you hear this hiss with the motor cover off or on or both?

Remove the spark arrestor and see if the hiss goes away. I'm not sure if your model uses a PCV valve, which operates off of manifold vacumm but check for any loose hoses around the intake and the carb.
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

I will remove that today when i give her an oil change, I checked the oil and it was black. so i figured I should change it. I will also change the gear oil today too. I hope to get her in the water tomorrow. But i need to figure out this sound first. Thanks for the reply.


oh, i hear the sound both. i have seen a few people say it just does this till it warms up. but im not sure, i have not really let her run very long.
 

scipper77

Commander
Joined
Sep 30, 2008
Messages
2,106
Re: Started boat today, i have a hiss sound coming from the motor? normal?

Check the power steering reservoir. You may be pumping air.
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: Started boat today, i have a hiss sound coming from the motor? normal?

I think 'people' are referring to the choke being partially closed til it warms up. If it's not that, getting a shall hose (3/8" will do) and pass one end around the carb and other places with the other to your ear. An intake leak can be a very bad thing for your engine.
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

so should i just take it to a mechanic and ask them to take a listen for me. I mean its like a car engine right. It should not make this hiss noise. i do not think i have power steering, so if its an air leak whats outcome.
 

scipper77

Commander
Joined
Sep 30, 2008
Messages
2,106
Re: Started boat today, i have a hiss sound coming from the motor? normal?

You don't think you have power steering?? If you can feel feedback in the steering you do not have power steering. Otherwise you probably do.

The reason I say to check is because I had a PS leak from a cracked hose and the reason I found is was because the engine was hissing like what you describe.
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

Well i have not taken the boat out yet. I also read that the bayliner 175 does not have power stearing. now i read this and i have not confirmed it yet, i am at work now and well like us all counting down the minutes till i can leave.
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

i looked it up, it has rack and pinion steering.

i am also wondering since its a 2007 could it still be under warranty. i know that could be a long shot.
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

so my dad come over yesterday and he took a listen, said its just the carb sucking air like its supposed too. Anyway he helped me get the oil changing. I left it drain over night as it seemed to go very very slow. I appreciate all the responses. i am having problems finding the correct oil filter. I went to west marine yesterday to get the oil and filter with all the info on my engine and well its not like auto zone you have to know what you need and well i got the wrong filter. The filter i took off was all painted black and i could not read any numbers on it. I am assuming the filter has never been replaced bc of the black paint on it. West marine only carries seria filters and well i will just take the one i have taken off in and match it up. so does anyone know what fuel filter mine takes.

i am waiting for the merc manual to come in the mail

should i use the mercruiser brand oil and stuff only or is quicksilver ok
and a seara filter.
 

futz

Banned
Joined
Jun 22, 2009
Messages
180
Re: Started boat today, i have a hiss sound coming from the motor? normal?

napa-1086
ph-30 fram can be bought in any wal-mart, as to oil well merc recommends 15-40, however i use straight 30 weight.

Cheapest wal-mart oil i can lay my hands on. Heres why, i use my boat maybe running time tops 40 hours a year the oil never looks dirty, in my mind i havn't even used 1/4 the life of the oil, but i change it every year anyway.
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

so does anyone know how to change the fuel filter for this engine. i got the correct oil filter at a local dealer, i also picked up a fuel filter, but cannot figure out how to get the old one out. are there steps to this.
 

scipper77

Commander
Joined
Sep 30, 2008
Messages
2,106
Re: Started boat today, i have a hiss sound coming from the motor? normal?

Go to the adults only sticky, you will find all of the help you need right there.
 

futz

Banned
Joined
Jun 22, 2009
Messages
180
Re: Started boat today, i have a hiss sound coming from the motor? normal?

grab the can and turn it, if it's stuck on use a oil filter wrench to loosen, and when you spin on the new one hand tight only, just like a oil can.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,126
Re: Started boat today, i have a hiss sound coming from the motor? normal?

Ryanhdd;2275498t said:
so my dad come over yesterday and he took a listen, said its just the carb sucking air like its supposed oo. Anyway he helped me get the oil changing. I left it drain over night as it seemed to go very very slow. I appreciate all the responses. i am having problems finding the correct oil filter. I went to west marine yesterday to get the oil and filter with all the info on my engine and well its not like auto zone you have to know what you need and well i got the wrong filter. The filter i took off was all painted black and i could not read any numbers on it. I am assuming the filter has never been replaced bc of the black paint on it. West marine only carries seria filters and well i will just take the one i have taken off in and match it up. so does anyone know what fuel filter mine takes.

i am waiting for the merc manual to come in the mail

should i use the mercruiser brand oil and stuff only or is quicksilver ok
and a seara filter.
If your engine has the new turn key start system [And I think you do] Then yes the varry loud hissing sound is normal untill the engine temp get to I believe 154 degrees then it should go away on it own And idle right around 640 rpms and while cold it will idle around 750 and slowly go down as it gets warmer.
 

WAVENBYE2

Lieutenant Commander
Joined
Apr 28, 2007
Messages
1,636
Re: Started boat today, i have a hiss sound coming from the motor? normal?

The wingnut was off my flame arrester and it made that hissing noise too, I pulled the cover off and saw that I had forgotten to put it back on, put it back on snug and hissing was gone
 

Ryanhdd

Cadet
Joined
Aug 11, 2009
Messages
16
Re: Started boat today, i have a hiss sound coming from the motor? normal?

well after changing the oil and the fuel filter and the case oil, we took her out yesterday. Absolutely no problems. the hiss went away as everyone has been saying, once she was warm. We had a great time. although is it normal for the boat to want to go left if you let the wheel go.

fyi i did look up everything in the adults only section and still did not find exact info for what i needed. anyway thanks for all your help
 

jloften

Cadet
Joined
Aug 14, 2009
Messages
6
Re: Started boat today, i have a hiss sound coming from the motor? normal?

If you had the motor trimmed up the steering will pull on way or the other... or your trim tab needs adjusting (a gray upside down fin looking piece above the prop).
 
Top