No water pressure to start the season.... again?

E

edonovan99

New Member
May 27, 2009
4
Chicago
Hello All,

Thanks in advance for any troubleshooting advice....

I bought a 2003 260 Sundancer last year and had a lot of trouble with overheating. A lot of things were tinkered with by a mechanic last year but eventually we decided it was a temperamental thermostat, because the problem went away with time. I never much liked that explanation though.

Just got back in the water this year after a full service, overpriced winter maintenance was done and everything looks good, except I'm getting no water pressure and I cant figure it out. I closed the seacock, disconnected the strainer and it was perfectly clean. I slowly opened the seacock and water rushed in, although not quite as forcefully as expected. The water pump is half a season old. Am I missing the obvious here? I'm mechanically apt but new to boats, I think there is something stupid I'm missing.

Should I rev the engine in neutral to try and get the thermostat opened? Could the cold May Lake Michigan water temperature have anything to do with this? I give up, getting ready to sink this thing and get my little 185BR back.
 
It sounds like you need to replace your raw water impeller. Running the engine with no water flow will not open your thermostat.
 
Thanks Ken- I think you are right a busted impeller is the only cause that makes any sense. I'm still learning my way around this cooling system so I was just blindly guessing. If the impeller is busted, is it possible that the marina wouldn't have noticed that when winterizing/summerizing? That really annoys me because they came up with so many stupid little things that "needed" fixing, so to miss a completely broken impeller that give me zero water pressure doesn't seem right.

I plan on taking it apart this weekend and figuring out how to replace the impeller. Its starting to dawn on me that I don't know as much as I should about how this cooling system really works, so the only solution is to grab my tools and start dismantling!!

Any background info on this stuff would go a long way- thanks!
 
(oops - hit the enter key by mistake)

OR... the cooling water may not be getting out of the system due to a blockage??? Just thinking about other possible options since the impeller is only half a season old.

Are you sure that the person replacing the impeller knew what he was doing?
 
if you boat is in the water and you want to be %100 sure it isn't pumping, on the back of the motor is a power steering cooler. If you are looking back at the motor or the cooler pull the hose off of the left side of it then start the motor. If the water pump is working fine in a few seconds you should have water gushing in. If not then you know its the water pump. If you have water gushing in when its running then it is just your water pressure sensor that is no good. I just had one of those go bad on me today, it read 0.0 lbs. at idle and when i replaced it it was fine.
 
you said that you shut the seacock valve off? so you don't have the water picking up thru the outdrive, that will make it easy to do water pump job in the water.
 
flflatrate said:
you said that you shut the seacock valve off? so you don't have the water picking up thru the outdrive, that will make it easy to do water pump job in the water.
Click to expand...

Can a water pump impeller be changed out if your water pickup is in the sterndrive? :huh:

I don't understand why Sea Ray decided to go with the water pickup in the sterndrive vs using a thru-hull / strainer with a shutoff for the 2006 260 Sundancer... sure would make changing out the impeller easier in water as I don't have a trailer :smt089.
 
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Hmmmmm. This sea cock you closed, this strainer you checked, where does the hose go to?

When you look in your engine compartment, how many sea cocks do you see?

Does your boat have air conditioning? Does your boat have a generator? Is your boat equipped with a macerator and waste tank sea cock?

Also, when you say you have zero water pressure, how do you know this? Describe this gauge and tell me what it says.

When you say the water pump is new, tell us exactly where this water pump is located. Do you mean the impeller inside the raw water pump for the engine cooling was changed or the fresh water pump or the water pump for the air conditioning?

Does your boat have raw water cooling or fresh water cooling? Do you have a place to add radiator fluid?

Pic of a fresh water cooled 6.2L merc
MX6.2SEACOREB3.jpg

Pic of a raw water cooled 6.2l merc
MX6.2MPIB3.jpg

The water pump is in the bottom left corner of both photos. Its behind the bottom left most pulley.

Now, tell us about the temperature gauge. What temperature does the boat normally get to when you are idling? How about on plane? When you say your boat has been overheating, when does it over heat? Is it when you are idling or on plane?
 
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dsteele1 said:
Can a water pump impeller be changed out if your water pickup is in the sterndrive? :huh:

I don't understand why Sea Ray decided to go with the water pickup in the sterndrive vs using a thru-hull / strainer with a shutoff for the 2006 260 Sundancer... sure would make changing out the impeller easier in water as I don't have a trailer :smt089.
Click to expand...


You have a Bravo III drive. The water pickup is thru the outdrive but the impeller is not inside the outdrive. The impeller is inside the outdrive is on the Alpha I drive.

On a Bravo III drive, the impeller is inside the raw water pump attached to the engine, bottom, starboard side. Yes, it can be changed with the boat in the water but it’s not easy. You need to flip the hose up or stuff a rag into it. Either way, you will get wet but it’s doable.
 
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Thanks again to all who responded, the sterndrives.com link was great...

Its definitely the raw water cooled Merc Bravo III- no radiator fluid. There is only one seacock (that I could find) and its mounted into the hull in front of the engine, I assume it leads out to the drive where it picks up water? From the seacock a hose leads to the strainer and then out to a small white plastic box(not sure what this is for?) before making its way to the raw water pump- will have to double check on the exact routing of the water hoses before I do anything. The raw water pump on the lower left side of the engine block was "allegedly" changed last winter. Even though it worked fine last season I told my storage marina to go ahead and put in a new one because I think the first owner was pretty lazy about doing any maintenance. (I NOW realize its equally lazy to just tell someone to do it rather than fixing it yourself!)

When I say it overheats, I mean that it idles for 5 minutes and as soon as it gets up to normal idle temp 175-190, it just keeps going until the alarm goes off. Consistent with either a bad thermostat or no cooling at all. The water pressure guage is part of the Smartcraft system and reads 0.0 at all times- normally it would read somewhere around 10 psi.

What makes you ask about the freshwater pump? I thought it was a separate system and runs off the electrical. Is that wrong?

If the water enters the cooling system through the seacock, where does it exit? I jwant to make sure I am putting this back together properly and not missing anything.. Thanks guys-
 
Im affraid you may be getting your systems mixed up. Take a few minutes down in the bildge and 1.) verify where that seacock is leading to, I think you'll find its your waste system. 2.) Look over the entire "house" water system, it has the electric pump that feeds the galley & head from your on board storage tank. 3.) The water pump that feeds the engine for cooling draws its water from the B3 outdrive.
 
To my knowledge, an 03 260 does not have a strainer for water to cool the engine. It pulls it up from the outdrive regardless of which outdrive you have??? I can't imagine anyone would go through the effort of rerouting the hoses to a strainer and new thruhull, which would only be possible on a Bravo outdrive anyway..
 
You're absolutely right about me getting the systems mixed up. So I think I have it now.... there are 3 water systems. The engine cooling systems which feeds from the drive, the graywater which feeds through the seacock, and the closed freshwater tank.

That would have been a nice surprise if I disconnected the hoses to the pump thinking no water could flow because the seacock was closed!!

How do you check to see if there is cooling water flowing into the drive? I guess I have to climb in the water and check for obstructions huh?
 
edonovan99 said:
Thanks again to all who responded, the sterndrives.com link was great...

Its definitely the raw water cooled Merc Bravo III- no radiator fluid. There is only one seacock (that I could find) and its mounted into the hull in front of the engine, I assume it leads out to the drive where it picks up water? From the seacock a hose leads to the strainer and then out to a small white plastic box(not sure what this is for?) before making its way to the raw water pump- will have to double check on the exact routing of the water hoses before I do anything. The raw water pump on the lower left side of the engine block was "allegedly" changed last winter. Even though it worked fine last season I told my storage marina to go ahead and put in a new one because I think the first owner was pretty lazy about doing any maintenance. (I NOW realize its equally lazy to just tell someone to do it rather than fixing it yourself!)

When I say it overheats, I mean that it idles for 5 minutes and as soon as it gets up to normal idle temp 175-190, it just keeps going until the alarm goes off. Consistent with either a bad thermostat or no cooling at all. The water pressure guage is part of the Smartcraft system and reads 0.0 at all times- normally it would read somewhere around 10 psi.

What makes you ask about the freshwater pump? I thought it was a separate system and runs off the electrical. Is that wrong?

If the water enters the cooling system through the seacock, where does it exit? I jwant to make sure I am putting this back together properly and not missing anything.. Thanks guys-
Click to expand...

I highly suggest you take some digital pictures of everything you are talking about and post them here so we can all SEE what you are looking at. I was a service tech for years (medical equipment) and trying to describe what you are seeing in words is nearly impossible in most cases. :smt101

The Bravo III sterndrive picks up the raw water from the lower unit of the sterndrive through small openings. The sea water pump (impeller) is driven mechanically by the engine drive belt. It circulates the water around the engine block and exits out the exhaust headers to the exhaust bellows at the transom under water. This is simplified of course. :wow:

Here's what you're getting into... may want to have a mechanic you trust do this... http://destinsharks.com/day-to-day-boating/61


 
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edonovan99 said:
.....How do you check to see if there is cooling water flowing into the drive? I guess I have to climb in the water and check for obstructions huh?
Click to expand...

I dont want to take credit from another members excellent reply, so here you go...

flflatrate said:
if you boat is in the water and you want to be %100 sure it isn't pumping, on the back of the motor is a power steering cooler. If you are looking back at the motor or the cooler pull the hose off of the left side of it then start the motor. If the water pump is working fine in a few seconds you should have water gushing in. If not then you know its the water pump. If you have water gushing in when its running then it is just your water pressure sensor that is no good. I just had one of those go bad on me today, it read 0.0 lbs. at idle and when i replaced it it was fine.
Click to expand...



Do you have air conditioning? That would explain your sea cock.
 
Another possibility is that water hose that brings sea water through the transom. If the boat was kept in salt water, salt will build up around the inserts that keep the hose in place and squeeze the raw water hose. This will cut off your water pressure and shorten your impeller life.
 
I just went through this problem in october 2010. I found out there is a problem with the intake hose inside the transom housing where one cannot see. The salt starts to build up around this rubber hose squeezing it shut until water pressure is lost and an alarm sounds for low pressure and overheat temp. SeaRay's fix is, remove sterndrive and replace escutchion plate and hose to fix the problem which will return is 3-4 years because of salt buildup. You cannot see it but if you squeese your fingers inside you can feel tha salt buildup as I was shown by a mechanic. There is no mention on any inspection nor service schedule for this problem and has to be a design flaw. I have a 6.2L merc with a bravo 3 sterndrive. The prpper repair is to install a seperate intake on the transom, eliminate the rubber hose going through the transom, placing a solid gasket covering where the old hose was going through and installing a fresh water hose engine flush assembly in the trunk on the swim deck. Marinemax only charged me about 1500 bucks for the repair. I can't repeat what my wife said! I blushed.....
 
Based on the information that the water pressure shows zero AND the water temp's go over 190 AND the high temp alarm sounds, I assume your engine is actually overheating.

As mentioned before, simply disconnect the cooliing water supply hose somewhere past the water pump but before it enters the engine, start it up, and see if water begins to pump out of the open hose. That way, you will start the process of elimination without spending any $$.

You have plenty of CSR members willing to help once you provide this info. :thumbsup:
 
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