Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 08-11-2015, 10:04   #16
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,359
Re: Mercruiser 5.0 noise - video - what is it?

Well....... if it's the GM based 5.0 motor it is readily available. I checked a couple years ago and a rebuilt longblock was only $1575. (Jasper engines) That's the nice thing about the GM based power plant... there were so many built for cars and trucks.
Be sure to check out the powerboat forums mentioned earlier, those guys know this stuff like the back of their hand...
__________________

__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 08-11-2015, 14:19   #17
Registered User

Join Date: Jun 2013
Posts: 124
Re: Mercruiser 5.0 noise - video - what is it?

Joe,

It sounds like valve train noise which could be stuck valve or lifter. Try the old yardstick in the ear method to try and isolate the noise. Good luck.
__________________

__________________
GPSocal is offline   Reply With Quote
Old 08-11-2015, 16:55   #18
Registered User

Join Date: Oct 2015
Location: cruising
Boat: Morgan 512 51'
Posts: 62
Re: Mercruiser 5.0 noise - video - what is it?

Ahhh, Has anybody considered the springs in the vibration damper? If the damper plate is orig 1996 it just could be rusted and falling apart springs
__________________
captain mitch is offline   Reply With Quote
Old 08-11-2015, 17:30   #19
Registered User

Join Date: Jul 2013
Boat: 1995 Larson Cabrio
Posts: 132
Re: Mercruiser 5.0 noise - video - what is it?

where is the vibration damper located?
__________________
Joe from ny is offline   Reply With Quote
Old 08-11-2015, 17:35   #20
Registered User
 
knotnow's Avatar

Join Date: Aug 2009
Location: Michigan
Posts: 225
Re: Mercruiser 5.0 noise - video - what is it?

From the sounds on the video a lot of the noise sounds tinny and inconsistent. My guess itís under the inspection plate at the bell housing area. The lower spectrum sound could be a longer than original bolt mounting the flex coupler to the flywheel hitting the block.
__________________
PATRIOTISM is supporting your country all the time AND your Government when it deserves it.

Mark Twain
knotnow is offline   Reply With Quote
Old 09-11-2015, 04:02   #21
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 1,102
Re: Mercruiser 5.0 noise - video - what is it?

Quote:
Originally Posted by captain mitch View Post
Ahhh, Has anybody considered the springs in the vibration damper? If the damper plate is orig 1996 it just could be rusted and falling apart springs
Quote:
Originally Posted by Joe from ny View Post
where is the vibration damper located?
Believe the vibration damper Capt mitch is talking about is the coupler between the flywheel and the outdrive. It is mounted on the flywheel under the flywheel housing. There are no springs in it. This is what it looks like



The torsional vibration damper is located at the front of the engine and is mounted on the crankshaft. The crankshaft pulley is bolted to it with three bolts and a center screw.

Sorry to hear about the second ahole at the marina, as noted those engines are readily available from a variety of sources, in a variety of states of build, at a variety of prices (should it come to that).

Took a quick look at Jamesport on Google earth, Long Island may not be the place to find the most uh...economical... boat mechanics. I'd shy away from marinas and try and find an independent with a good reputation, maybe talk to a Mercruiser rep for advice, or someone from a local boating organization or club.

As a long shot, after listening again I wonder if it might be a problem with the exhaust manifold. Loose bolt or warped flange or bad gasket between the manifold and the head? Water does not flow into those manifolds from the heads, there could be an exhaust leak that is hidden, intermittent and/or dependent on certain pressure conditions to make itself audible.
__________________
jimbunyard is online now   Reply With Quote
Old 09-11-2015, 06:04   #22
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,980
Re: Mercruiser 5.0 noise - video - what is it?

That noise is "low" and "deep" in the engine... Seems timed at crank speed...

To me, it seems that...
If it's not a rod bearing.... It's the aft end of the crank/U-joint/flywheel...
__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Old 09-11-2015, 06:33   #23
Registered User
 
Juho's Avatar

Join Date: Apr 2015
Location: Finland
Boat: Nauticat 32
Posts: 716
Re: Mercruiser 5.0 noise - video - what is it?

Check also the engine support, i.e. the connection between the engine and the hull and dampers there. (I don't exactly know what those components are called in English) We once had a noise and vibration problem coming out from there (not in a boat though).
__________________
Juho is offline   Reply With Quote
Old 09-11-2015, 12:32   #24
Registered User

Join Date: Jun 2015
Posts: 315
Re: Mercruiser 5.0 noise - video - what is it?

Take a length of broom stick and put one end on the block one end to your ear, acts as a stethescope(?), you can isolate where the noise is comming from by testing different spots on the block, valve covers etc.
Long handled screwdriver works well for areas easier to reach. Put the plastic end to your ear!
Honestly can't believe somebody hasn't suggested this already, one of the oldest mechanics tricks in the book for diagnosing engine noises.
__________________
Siberianhusky is offline   Reply With Quote
Old 09-11-2015, 21:21   #25
Registered User

Join Date: Jul 2013
Boat: 1995 Larson Cabrio
Posts: 132
Mercruiser 5.0 noise - video - what is it?

I was just trying to rule out any issues that could be fixed without taking the motor out. When they put it back in the boat after the flywheel and starter job, they hit the back of the engine hatch opening with the distributor cap and broke an electrode tower. Just cracked it and left it broken at a 45 degree angle. They never even noticed it during their winter service. I only spotted it when trying to diagnose my current issue. This photo is after I tried to jam it back on. It was quite skewed initially. The cap was new that season also.
Click image for larger version

Name:	ImageUploadedByTapatalk1447129275.735993.jpg
Views:	54
Size:	209.9 KB
ID:	112690


Sent from my iPad using Tapatalk
__________________
Joe from ny is offline   Reply With Quote
Old 09-11-2015, 21:38   #26
Registered User

Join Date: Jul 2013
Boat: 1995 Larson Cabrio
Posts: 132
Re: Mercruiser 5.0 noise - video - what is it?

That's why I don't go anywhere near that yard again.


Sent from my iPad using Tapatalk
__________________
Joe from ny is offline   Reply With Quote
Old 11-11-2015, 16:26   #27
Registered User

Join Date: Jul 2013
Boat: 1995 Larson Cabrio
Posts: 132
Re: Mercruiser 5.0 noise - video - what is it?

Here is a new video I shot today with the camera closer to the motor.
https://youtu.be/lsU9zwnSMlA


Sent from my iPad using Tapatalk


Sent from my iPad using Tapatalk
__________________
Joe from ny is offline   Reply With Quote
Old 11-11-2015, 16:44   #28
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,359
Re: Mercruiser 5.0 noise - video - what is it?

Quote:
Originally Posted by Joe from ny View Post
Here is a new video I shot today with the camera closer to the motor.
https://youtu.be/lsU9zwnSMlA


Sent from my iPad using Tapatalk


Sent from my iPad using Tapatalk
When you slow the engine down it really starts sounding like some kind of rocker/tappet noise. Pretty loud and heavy though. It's a tough one , but I would likely be looking under the rocker covers first. Almost sounds like a bit of exhaust leak mixed in there too... Could be a rod I suppose... bottom line is it sounds related to one cylinder somehow; rod, rod bearing, valve, pushrod issue... etc
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 11-11-2015, 17:29   #29
Registered User

Join Date: Jun 2015
Posts: 315
Re: Mercruiser 5.0 noise - video - what is it?

Try the broomstick! Tough crowd!
https://www.gunandgame.com/threads/r...to-tell.96429/
Here's a video about it
Engine Stethoscope Using A Broomhandle
__________________
Siberianhusky is offline   Reply With Quote
Old 12-11-2015, 06:30   #30
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,980
Re: Mercruiser 5.0 noise - video - what is it?

Quote:
Originally Posted by Cheechako View Post
When you slow the engine down it really starts sounding like some kind of rocker/tappet noise. Pretty loud and heavy though. It's a tough one , but I would likely be looking under the rocker covers first. Almost sounds like a bit of exhaust leak mixed in there too... Could be a rod I suppose... bottom line is it sounds related to one cylinder somehow; rod, rod bearing, valve, pushrod issue... etc
man that is a tough one.... Sounds higher up in this video than the others...

The good news is that if you keep running it, there will be enough wear evidence to find it easily!

Go to Autozone/Advanced/O'rielly and pick up one of these...
Amazon.com: Lisle 52750 Stethoscope Kit: Automotive
__________________

__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Reply

Tags
cruise, cruiser, noise

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
7.4 MerCruiser Engine Life SeaAir Engines and Propulsion Systems 14 28-08-2011 16:49
3.0 mercruiser charging problem brn77 Electrical: Batteries, Generators & Solar 10 20-06-2011 05:29
bell housing mercruiser cutbrain Propellers & Drive Systems 0 29-03-2009 09:59
Mercruiser Corrosion Protection Ripoff Chief Engineer Construction, Maintenance & Refit 2 23-10-2008 21:14
Mercruiser Bravo 3 Problem! Suggestions?? Alondra Powered Boats 7 05-08-2008 18:22



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:56.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.