Go Back  Offshoreonly.com > Technical > Do It Yourself, Boating on a Budget
Detecting a failed lower bearing >

Detecting a failed lower bearing

Notices

Detecting a failed lower bearing

Old 05-19-2011, 09:22 AM
  #1  
Registered
Thread Starter
 
Join Date: May 2011
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default Detecting a failed lower bearing

OK, my oil pump temporarily failed and i blew a lower bearing. I was going to replace the old motor, but am considering a boat i can get at a great price that is, physically and cosmetically, in better shape. However, what i discoverred with my motor is that, at low rpm and load, the boat ran fine, no vibration or knock until higher rpm and load.

So,my question: Is there a test with a motor sitting or at best on muffs that i can do to check for this (a failed lower bearing)? I'm thinking a compression test won't work, but a vaccum test might.

Any assistance/thoughts would be appreciated.

Al T

Last edited by whatsleft; 05-19-2011 at 09:26 AM.
whatsleft is offline  
Old 05-19-2011, 12:02 PM
  #2  
Registered
iTrader: (1)
 
Join Date: Jun 2004
Location: Omaha, Nebraska. Boat on the Mighty Mo! Longest river in the USA!
Posts: 1,944
Received 37 Likes on 23 Posts
Default

OK I have to be the first one to ask
how does an oil pump temporarily fail?

I think you answered your own question
no vibration or knock until higher rpm and load

More than likely You spun a bearing.

Cut open the oil filter, see if it shines.

Sorry to hear it, most of us have been there done that.
1BIGJIM is offline  
Old 05-19-2011, 01:09 PM
  #3  
Registered
 
Join Date: Mar 2009
Location: OFallon,Mo.
Posts: 1,758
Likes: 0
Received 3 Likes on 2 Posts
Default

Compression or vacuum test won't tell anything about a bad bearing. If you spun or wiped out a bearing you will have very low oil pressure. If that is what happened you shouldn't even be running it.
picklenjim is offline  
Old 05-19-2011, 04:23 PM
  #4  
jwp
Registered
Gold Member
 
Join Date: Nov 2010
Location: Getzville, N.Y.
Posts: 101
Likes: 0
Received 0 Likes on 0 Posts
Default

After the engine has sat a while, You may be able to hear it knock if you have someone else start it ,And you stick you head by the engine. You will have a second or two before the oil pressure comes up to hear it....are you sure its not detonation/pre-ignition?
jwp is offline  
Old 05-20-2011, 09:51 PM
  #5  
Registered
iTrader: (7)
 
Join Date: Feb 2009
Location: NW Michigan
Posts: 8,293
Received 1,476 Likes on 801 Posts
Default

Originally Posted by 1BIGJIM
OK I have to be the first one to ask
how does an oil pump temporarily fail?

I think you answered your own question
no vibration or knock until higher rpm and load

More than likely You spun a bearing.

Cut open the oil filter, see if it shines.

Sorry to hear it, most of us have been there done that.


I would like to blame an oil pump failure on the ones I've grenaded. lol.. I've seen some of those sludge turds of bearing debris and it's not what I would say a very good feeling. I had simular symtems on the dyno last year and immeadiately pulled the engine and pan as well as all the main caps. All was fine including the filter with the exception of the normal break in debris. It wound up being a collapsed lifter. Under normal circumstances I would have more than likely found the cause with out the hassle however I was a little concerned being a new engine.

Regardless if you ran it much after you heard the knock more than likely your looking at something that's not a quick fix. Then again in this hobby it's not that often anything is a quick fix. Good luck though.

Last edited by getrdunn; 05-20-2011 at 09:53 PM.
getrdunn is offline  
Old 05-21-2011, 11:04 AM
  #6  
Registered
 
Join Date: Sep 2008
Location: Tampa Bay Area Florida/ North Miami Florida
Posts: 905
Received 38 Likes on 26 Posts
Default oil pump

Temporary failure of oil pump = ran out of oil...lol...
Anyway take off the filter and cut it open. If you see metal take the boat to the shop and also bring your wallet. If no metal you can try putting in 2 bottles of slick 50 and then top off with 20w 50 and fire it up. Let it idle on the hose for 30 min if there is little or no noise. Then take it to the lake and run the piss out of it. I have seen this work 3 of 5 times. Bought some 1 season and others 3 seasons. 1 guy did throw a rod through the block but he was already screw anyway and its usually easier to buy a long block then rebuild a non hi-perf motor.

Chris
Blueabyss is offline  

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 On
Pingbacks are On
Refbacks are On


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.