Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Cooling System

Reply
 
Thread Tools Display Modes
  #1   IP: 50.198.141.249
Old 09-17-2013, 09:53 AM
pdecker's Avatar
pdecker pdecker is offline
Senior Member
 
Join Date: Jan 2005
Location: Fort Lauderdale, FL
Posts: 64
Thanks: 25
Thanked 5 Times in 2 Posts
Send a message via AIM to pdecker Send a message via Yahoo to pdecker Send a message via Skype™ to pdecker
No water flow AFTER replacing impeller

I have a late model raw water cooled A4. I replaced the impeller for the first time in three years. The old one was in good condition, with no broken vanes. Coolant flow and temperature has been fine for the whole three years.

I'm doing the ICW to Florida in a few weeks, so I replaced the impeller. A couple weeks ago, I pulled the boat out, painted the bottom, and made sure the intake strainer was clear. Now, I get almost zero water flow and the temperature quickly goes up to 190 F once I start the engine.

I removed the water pump cover plate and removed to make sure it was installed correctly. Everything seems to be installed correctly. I started the engine again, got a dribble of water, and then nothing, following by high temperature. What could I have done? What could it be? I'm thinking blockage somewhere, but how and where?
Reply With Quote
  #2   IP: 24.152.131.153
Old 09-17-2013, 10:07 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
Do you still have the old impeller on hand? If yes, compare the thickness to the new impeller. Unless the impeller fits against the faceplate and the back of the pump cavity its performance can be reduced to nearly zero.
Attached Images
 
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
  #3   IP: 161.213.49.150
Old 09-17-2013, 11:26 AM
JOHN COOKSON JOHN COOKSON is offline
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,500
Thanks: 54
Thanked 855 Times in 629 Posts
1. Remove the new impeller and compare the thickness to the old impeller.
2. Reinstall the old impeller.
3. Install the hose on the intake and pour some water down it then turn the engine a bit to prime the pump.
4. Raise your right hand and read out loud: "Don't fix it if it isn't broken".
5. Have a good day and a great cruise.

TRUE GRIT
Reply With Quote
  #4   IP: 198.11.8.218
Old 09-17-2013, 11:27 AM
BunnyPlanet169's Avatar
BunnyPlanet169 BunnyPlanet169 is offline
Afourian MVP, Professor Emeritus
 
Join Date: May 2010
Location: York, ME
Posts: 952
Thanks: 25
Thanked 94 Times in 67 Posts
Recent experience

I've been through this recently.... It's pretty simple to at least localize the problem. For each step, reconnect the last good step until the blockage shows itself...

Thru hull valve to pump? Take the hose off the pump and see if there is clear flow. This should be an alarming amount of water even in a 3/4" hose. Air pockets before the pump can cause more problems than you would imagine.

Pump output? Put a longer hose on the pump output to a bucket and run the engine for 10 seconds - about a gallon if you're lucky, and a half gallon at idle wouldn't surprise me.

Bypass valve? Do you have one?

Are you using a thermostat? Take it out for testing.

Take the hose from the thermostat output into a bucket and run the engine for 10 seconds. Same flow as from pump? Bypass vs no bypass?

Take the hose off the exhaust manifold output, and run the engine for 10 seconds. Same flow as from pump?
__________________
Jeff


S/V Bunny Planet
1971 Bristol 29 #169
Reply With Quote
  #5   IP: 50.198.141.249
Old 09-17-2013, 12:11 PM
pdecker's Avatar
pdecker pdecker is offline
Senior Member
 
Join Date: Jan 2005
Location: Fort Lauderdale, FL
Posts: 64
Thanks: 25
Thanked 5 Times in 2 Posts
Send a message via AIM to pdecker Send a message via Yahoo to pdecker Send a message via Skype™ to pdecker
All good ideas

I'll try them all until the thing works, and I'll let you know what worked here. Please keep the ideas coming, too! The new impeller LOOKS like it is the right size, but I'll remove it and compare it to the old one (which I had to partially destroy to get it off the shaft).
Reply With Quote
  #6   IP: 161.213.49.150
Old 09-17-2013, 02:07 PM
JOHN COOKSON JOHN COOKSON is offline
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,500
Thanks: 54
Thanked 855 Times in 629 Posts
Maybe You'll Luck Out

Try priming the new impeller before doing anything further.

TRUE GRIT
Reply With Quote
  #7   IP: 198.11.8.218
Old 09-17-2013, 02:45 PM
BunnyPlanet169's Avatar
BunnyPlanet169 BunnyPlanet169 is offline
Afourian MVP, Professor Emeritus
 
Join Date: May 2010
Location: York, ME
Posts: 952
Thanks: 25
Thanked 94 Times in 67 Posts
+1 for what John said.

I was flummoxed for about 5 minutes till I figured out the pump won't self prime. It relies on water pressure from a below-the-waterline inlet. I had put a longer hose into a bucket for acid flushing and guess what? Nothing happens when the hose has air in it.
__________________
Jeff


S/V Bunny Planet
1971 Bristol 29 #169
Reply With Quote
  #8   IP: 128.183.140.38
Old 09-17-2013, 05:29 PM
edwardc's Avatar
edwardc edwardc is offline
Afourian MVP
 
Join Date: Aug 2009
Location: Laurel, MD
Posts: 2,509
Thanks: 153
Thanked 595 Times in 388 Posts
Quote:
Originally Posted by BunnyPlanet169 View Post
+1 for what John said.

I was flummoxed for about 5 minutes till I figured out the pump won't self prime. It relies on water pressure from a below-the-waterline inlet. I had put a longer hose into a bucket for acid flushing and guess what? Nothing happens when the hose has air in it.
Others have noted this too, and I'm really puzzled.

When I did my rebuild, I had the engine on the bench and a 5-gal bucket on the floor. It had no problem priming a dry system through that 3+ feet of empty hose.

It seems there are cases where it will prime, and cases where it wont.

But I have no idea what makes the difference.
__________________
@(^.^)@ Ed
1977 Pearson P-323 "Dolce Vita"
with rebuilt Atomic-4

Reply With Quote
  #9   IP: 198.11.8.218
Old 09-17-2013, 05:39 PM
BunnyPlanet169's Avatar
BunnyPlanet169 BunnyPlanet169 is offline
Afourian MVP, Professor Emeritus
 
Join Date: May 2010
Location: York, ME
Posts: 952
Thanks: 25
Thanked 94 Times in 67 Posts
My favorite physics joke

It's like the thermos.

It keeps hot things hot, and cold things cold.

How does it know?
__________________
Jeff


S/V Bunny Planet
1971 Bristol 29 #169
Reply With Quote
  #10   IP: 76.7.135.1
Old 09-17-2013, 06:23 PM
Marian Claire's Avatar
Marian Claire Marian Claire is offline
Afourian MVP
 
Join Date: Aug 2007
Posts: 1,797
Thanks: 33
Thanked 129 Times in 94 Posts
OK. I will be the jerk and ask. Did you open the RW intake after servicing the pump? Other than that if you need anything as you pass thru the Oriental/Neuse River area let me know. Be happy to help if I'm at the boat.
Dan S/V Marian Claire
Reply With Quote
  #11   IP: 161.213.49.150
Old 09-17-2013, 06:51 PM
JOHN COOKSON JOHN COOKSON is offline
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,500
Thanks: 54
Thanked 855 Times in 629 Posts
+1 On Being Puzzled

Quote:
Originally Posted by edwardc View Post
Others have noted this too, and I'm really puzzled.It seems there are cases where it will prime, and cases where it wont.
But I have no idea what makes the difference.
I'm RWC.
For my ~ first 20 years of A4 ownership I never had to prime the water pump after servicing it.
Then maybe ten years or so ago the pump wouldn't prime by itself after I took it apart.
Now I prime the water pump any time I take it apart to avoid the "drama".
Also the heat generated by running the impeller dry doesn't do it any good.

TRUE GRIT
Reply With Quote
  #12   IP: 24.152.131.153
Old 09-17-2013, 08:15 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
John, Bunny

There's a chance your inability to dry prime as the pump ages may be due to cavity wear. It results in the same internal leakage across the edges of the impeller vanes as the earlier picture shows. Same symptom, different cause.

About 2 years ago I measured the cavity depth on mine and compared it to Oberdorfer's published specification and sure enough, I had measurable and significant wear. I figured I'd give repair a try before replacement (where's the risk?) which thus far has been successful. Mine primes dry from a bucket, no problem.

Once again, another no flow report:
http://www.moyermarine.com/cgi-bin/s...ey=KTAS_01_563
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
  #13   IP: 74.78.27.200
Old 09-17-2013, 11:02 PM
BunnyPlanet169's Avatar
BunnyPlanet169 BunnyPlanet169 is offline
Afourian MVP, Professor Emeritus
 
Join Date: May 2010
Location: York, ME
Posts: 952
Thanks: 25
Thanked 94 Times in 67 Posts
Neil - you are certainly correct that internal tolerances must make a difference in the ability to prime or not, and any wear from nominal must make self-prime more difficult. Especially blow-by on the faces. FWIW, mine is a 2 year old MMI. I've had some 'dry' experiences this year, however, and I'll be looking at it more closely on the hard this Fall. The flow sensor is a definite for me.
__________________
Jeff


S/V Bunny Planet
1971 Bristol 29 #169
Reply With Quote
  #14   IP: 24.152.131.153
Old 09-17-2013, 11:37 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
Quote:
Originally Posted by BunnyPlanet169 View Post
The flow sensor is a definite for me.
It's cool that the sensor is fully compatible with the existing alarm system instead of having to pay for redundancy. Way cool.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
  #15   IP: 165.154.103.237
Old 09-18-2013, 08:38 AM
thumbdoctor's Avatar
thumbdoctor thumbdoctor is offline
Senior Member
 
Join Date: Sep 2013
Location: Quebec, Canada.
Posts: 30
Thanks: 0
Thanked 0 Times in 0 Posts
I've noticed on a lot of pumps that don't self prime the cam shoe has irregular wear (taper towards the cover plate). This reduces the displacement of the pump too.
Reply With Quote
  #16   IP: 50.198.141.249
Old 09-18-2013, 04:14 PM
pdecker's Avatar
pdecker pdecker is offline
Senior Member
 
Join Date: Jan 2005
Location: Fort Lauderdale, FL
Posts: 64
Thanks: 25
Thanked 5 Times in 2 Posts
Send a message via AIM to pdecker Send a message via Yahoo to pdecker Send a message via Skype™ to pdecker
Smile Solved: it wasn't self-priming

I disconnected the raw water intake from the pump and opened the seacock. As water was flowing in, I stuck the hose back on the pump and re-installed the hose clamp. I started the engine, and got plenty of water out the exhaust almost immediately.

There are signs of wear on the pump, so that is probably why it does not self-prime anymore. I will buy a new pump next year.

Phil Decker
S/V Catmandu
1982 Catalina 27
Reply With Quote
Reply

Tags
impeller, pump

Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Low water flow dcsavitzky Cooling System 5 06-28-2013 08:47 PM
Replacment impeller for Oberdorfer not making the grade Baltimore Sailor Cooling System 17 06-28-2013 11:57 AM
No water flow in raw water cooling system LIG-C27 Cooling System 7 08-08-2011 02:56 PM
Oberdorfer water pump impeller replacement CalebD General Maintenance 0 04-05-2010 01:10 PM
Strange Water Flow Problem ChickenEye Cooling System 9 05-31-2007 07:28 AM


All times are GMT -4. The time now is 08:29 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved