motor won't pull in lake water

allenu

Recruit
Joined
Jul 16, 2013
Messages
4
I have a 2000 4.3 litre that is overheating because it is not pulling in cooling water from the lake. I replaced the impeller and thermostat before realizing raw water was not coming in. I pulled all the hoses at the thermostat and poured water into them to verify there is no clogged passageways. I pulled the outdrive and did not see any obvious problems. The only thing I have not done is put in a new water tube seal.

It sounds like I have an air leak in the raw water passageway. Is there a chance that a worn water tube seal would cause this much trouble?
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: motor won't pull in lake water

Some raw water pumps had plastic fittings going into the metal pump housing and those can leak where they go into the housing. I am not sure when those came into play, but if you search in this category you will find recent posts dealing with this. If yours is all metal then that is not a place to look.
 

vwbugman69

Petty Officer 2nd Class
Joined
Jul 11, 2011
Messages
116
Re: motor won't pull in lake water

Also make sure that the oring sealing the housing to the pump is replaced at the same time as the impeller. In my case, I never removed the old one and had "doubled up" orings, effectively causing an air leak so I would not be able to prime the pump without reving to 2k.

After the pump was primed it would pull water all day no problem.
 

allenu

Recruit
Joined
Jul 16, 2013
Messages
4
Re: motor won't pull in lake water

Some raw water pumps had plastic fittings going into the metal pump housing and those can leak where they go into the housing. I am not sure when those came into play, but if you search in this category you will find recent posts dealing with this. If yours is all metal then that is not a place to look.

Thanks for the help. I have an all metal pump housing, so I think I'm good there.
 

nitwhit

Seaman
Joined
May 22, 2010
Messages
56
Re: motor won't pull in lake water

What's the full model # of you engine? There are different styles of pumps (crank or bracket mounted). Will it work on muffs or have you tried as the pressure from those can hide most air leaks?

You also need to look at the stickies for the overheat diagnosis manual that's in the Volvo Penta Information
 
Last edited:

allenu

Recruit
Joined
Jul 16, 2013
Messages
4
Re: motor won't pull in lake water

Look at item #1 in the Volvo stickies.

VP.*/ 357328

I appreciate everyone's help with this problem. I found out the problem was a defective O-ring sealing the impeller. Amazing how much trouble a defective $2.00 part can cause.
 

vwbugman69

Petty Officer 2nd Class
Joined
Jul 11, 2011
Messages
116
Re: motor won't pull in lake water

Glad to hear you found the problem. It took me an entire season to finally find my oring issue and I know how frustrating an overheat can be.
 
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