1996 Volvo Penta Cobra SX Overheat

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BrocheN

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Hello all,

I have a 1996 Reinell 184BRXL with a Volvo Penta Cobra SX i/o. I took the boat out wakeboarding for about an hour and a half and then see my temperature gauge rise between 225-250. We stop the boat to let it cool down; floated to shore. 40 minutes later I tried starting the boat and no cranking happened. We get towed in. The next day I hook up the earmuffs and notice no water is being taken in; all water is shooting through the edges of the earmuffs. I then try starting the boat and it starts right up, running great. So what is the heating problem caused by? I hooked up the ear muffs, unhooked the hose to the thermostat (no water, engine off or on). I then unhooked the feed hose to the water pump (no water, engine off or on). Also, two small rubber chunks came out of this hose. I then unhooked a hose in the back of the engine, where the feed from the ear muffs is coming from (no water, engine off or on). What is the problem here? Is there an impeller in the outboard that is not allowing water to be taken in? Why isn't there water getting to the feed hose from the earmuffs? Please help!

Philip
 

ferrall

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Re: 1996 Volvo Penta Cobra SX Overheat

Water intake impeller not waterpump (engine circulating pump). They need to be replaced every few years
 

Don S

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Re: 1996 Volvo Penta Cobra SX Overheat

Your engine has a belt driven raw water pump. It has a rubber impeller with vanes. They should be replaced every couple of years, If not they get old, don't pump water, break off the vanes and those broken rubber pieces get stuch in other places and cause more overheat. Since that flow of water is the only thing that cools your engine, the raw water pump impeller is the first thing you need to check.
You can Click Here and after finding your model number (not year) download the OEM manuals. They will show you where the pump is and how to change the impeller.
 

BrocheN

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Re: 1996 Volvo Penta Cobra SX Overheat

Water intake impeller not waterpump (engine circulating pump). They need to be replaced every few years

Hey ferrall,

So there is a water intake impeller that is in the outdrive? This is most likely what I need to replace? Is it a tough job?
 

BrocheN

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Re: 1996 Volvo Penta Cobra SX Overheat

Your engine has a belt driven raw water pump. It has a rubber impeller with vanes. They should be replaced every couple of years, If not they get old, don't pump water, break off the vanes and those broken rubber pieces get stuch in other places and cause more overheat. Since that flow of water is the only thing that cools your engine, the raw water pump impeller is the first thing you need to check.
You can Click Here and after finding your model number (not year) download the OEM manuals. They will show you where the pump is and how to change the impeller.

Don S,

Thanks for your reply! There is no water getting to the water pump. Ferrall in the above post mentioned that there is a water intake impeller. Do you have any links to this?
 

ferrall

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Re: 1996 Volvo Penta Cobra SX Overheat

I'm not sure on the 5.0s. I have a 5.8 Ford so it may be different. My pump is belt driven off the engine and sits in the lower left corner of the engine if you're looking towards the stern. It actually was pretty simple to replace. I'd just find your tstat and follow the hoses down until you find it. It should be either belt driven or engine driven (off the crank).
 

Don S

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Re: 1996 Volvo Penta Cobra SX Overheat

Thanks for your reply! There is no water getting to the water pump.

The impeller has to work to help suck the water up to the raw water pump.

Did you even look at the link or download the manual?
 

BrocheN

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BrocheN

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Re: 1996 Volvo Penta Cobra SX Overheat


I am trying to figure out how the impeller is the problem, though. No water gets passed the wall between the outboard and inboard. So how can the impeller be bad if no water even gets to it? Does the impeller really suck in water that hard?
 

bruceb58

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Re: 1996 Volvo Penta Cobra SX Overheat

I am trying to figure out how the impeller is the problem, though. No water gets passed the wall between the outboard and inboard. So how can the impeller be bad if no water even gets to it? Does the impeller really suck in water that hard?
What hose are you pulling off to see if there is water getting up to the motor?
 

BrocheN

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Re: 1996 Volvo Penta Cobra SX Overheat

What hose are you pulling off to see if there is water getting up to the motor?

Not sure what the hose is called, but I first pulled the hose to the thermostat (no water). Then the hose that feeds the water pump (no water). Then the hose that comes directly from the outboard that connects to the water pump hose (no water).
 

bruceb58

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Re: 1996 Volvo Penta Cobra SX Overheat

So you took off hoses 8 and 9 that are hooked up to #31. That is the raw water pump. the circulating pump is #16. You know that there is a difference between those two pumps right? The hoses #8 and #9 are relatively Small diameter...little bigger than an inch or so.

12218.gif
 

BrocheN

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Re: 1996 Volvo Penta Cobra SX Overheat

So you took off hoses 8 and 9 that are hooked up to #31. That is the raw water pump. the circulating pump is #16. You know that there is a difference between those two pumps right? The hoses #8 and #9 are relatively Small diameter...little bigger than an inch or so.

12218.gif

There is no water getting to hose 8 or 9.

Edit: Ok I read your post wrong. So the circulating pump #16, has a bad impeller?
 

ferrall

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Re: 1996 Volvo Penta Cobra SX Overheat

I am trying to figure out how the impeller is the problem, though. No water gets passed the wall between the outboard and inboard. So how can the impeller be bad if no water even gets to it? Does the impeller really suck in water that hard?


Yes, it does suck that hard. That's the only way water can get to your engine, THE ONLY WAY! Mercruisers have the impeller in the outdrive, Volvos have a pickup in the outdrive attached to a hose that goes thru the hull to your impeller pump and from your impeller to your tstat housing/manifold. I'm telling you, it's the impeller.
 

BrocheN

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Re: 1996 Volvo Penta Cobra SX Overheat

Yes, it does suck that hard. That's the only way water can get to your engine, THE ONLY WAY! Mercruisers have the impeller in the outdrive, Volvos have a pickup in the outdrive attached to a hose that goes thru the hull to your impeller pump and from your impeller to your tstat housing/manifold. I'm telling you, it's the impeller.

The raw water pump impeller, or the circulating pump impeller?
 

bruceb58

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Re: 1996 Volvo Penta Cobra SX Overheat

The impeller that we are talking about is in #31. You can hook a hose up to the hose that goes back to the drive(i can't remember if its 8 or 9) and make sure that passage is clear if you want. If you haven't changed that impeller in the last 2 years, you should replace it.

You don't replace the circulating pump impeller.
 

ferrall

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bruceb58

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Re: 1996 Volvo Penta Cobra SX Overheat

Just to be clear, you do know that the raw water pump is down on the lower starboard side of the the engine correct(left if you are facing the engine while inside the boat)? Not the one in the center of the engine.
 
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