Recap my cooling issue

rasbury

dang I am stumped! I have had a couple issues I have been working on, let me start from the beginning.

I have a 2005 270 5.7, bought around this time frame last year. Always had been a "slow" starting starter in play and the key would not always activate the ignition. So, I was taking the neighbors out the next day and was out there bumping the ignition to see if it would work or not, seemed OK. So, at the ramp, in the water started " slow " as usual, backed it off the trailer and up to the dock and got off, left it running to warm as I helped others with their stuff. Did notice the power steering hard but thought it was low on fluid. So, just about when we start to get onboard, high temp goes off and I turn it right off. Further inspection and the drive belt is broke and the raw water pump is frozen. So, home we go. I get the water pump off and very lucky that there are two big pieces jamming it up, new impeller back in, all looks good and back together. Go to test and starter is done. Did all the tests,come to the conclusion it is the starter, get rebuilt and back on last night. So, put the muffs on the bravo three out drive. I have a fresh water cooled system so I have two hoses- one to the out drive and one to a thru hull which the raw water pump pulls water from both hoses, into the strainer and then into one hose and then to the motor.  Fires right up and sounding good! So, I'm watching the temp gauge, climbs slowly to 175...and then keeps going. I shut it down. I look in the strainer and there is no water in it. I removed the cover to it and turned the water back on to make sure I did not have back pressure and still, no water coming through from the out drive. I have not really looked at the out drive manual, not sure I have one, but should that water not be rushing through? Are there any other valves, check valves? I only ran the boat out of water on muffs a couple of times, once a short time to heat the oil to change it and anther I thought to flush it after salt water use. The water is trailer kept so I'm really puzzled.  It was also lift kept previous. I'm going to go put it in the water and see if the thru hull will pull water into the system, my fake lake will not fit properly to do that out of water- have had no over heating issues at all since I purchased, maybe it has not been pulling through the foot the whole time.  

Michael T

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rasbury

everything looked fine..so, before I  went to the ramp, I pulled the supply line off the foot at the sea strainer,put a hose in it to make sure water would come out the foot which it did no problem. When I put the muffs on the foot, water won't come up through the foot to the strainer. Did the same for the thru hull fitting to the strainer as well. I think my fake lake is bottoming out on the hull fitting so I guess I understand why that does not work, but the muffs on the foot? When you start the boat, should not the sea strainer fill immediately ? I put it in the water with the same result, started coming up to temp but no water in the strainer.....I'm stumped! Even if the pump got toasted, I should be able to get water to the strainer with the muffs? I guess I am pulling that water pump back off and see what happened to the impeller?

LaRea

I'm tellin' ya -- it has to be a piece of loose debris inside the outdrive pickup hose acting like a 1-way check valve.  But maybe that's not the entire problem.  

My 342 with the same dual-pickup arrangement was notoriously finicky whenever I launched the boat after having it out of the water.  If I just started the engines at idle, the pumps would rarely prime on their own.  Sometimes, I could prime the pumps by revving the throttles for a few seconds.  Most of the time, I would have to prime the pumps manually like this:

1) Disconnect the water hose on the output side of the strainer.
2) On the body of the water pump, loosen the air bleed valves (two blue plastic butterfly screws).
3) Manually fill the hose with water until water flows out through the bleed valves.
4) Close the bleed valves.
5) Reconnect the hose to the strainer, trying not to let any water leak out.
6) Fill the strainer with water.
7) Start the engine and hope the pump works.

The key is to make sure there's water actually inside the pump body when you start the engine.  I don't know why that was necessary, but it usually worked.

rasbury

Wow,never had this issue, is there a thermostat on the raw water side that could be an issue? Will check the book...didn't your impellers melt trying to prime?

LaRea

Yes, I did melt some impellers.  It only takes a few minutes of running them dry.

It's something about the dual-pickup plumbing.  There was another Rinker in my marina with the same issue.

rasbury

I ran mine for prob 10/15 mins...guessing that impelled is done..

Black_Diamond

I've never heard/seen of this dual water pick up set up.  What's the purpose?

rasbury

black-I have a fresh water cooking system and I guess, for some reason, it needs a lot of water, You have the closed cooling side that has it's own water pump which cools the block and the coolant goes through a heat exchanger. The heat exchanger is cooled with raw water and also the manifolds just like any other boat. I don't understand why either as both hoses go into one hose so I don't see where the volume has really been increased....

Black_Diamond

Fresh water cooling here too, but mine all pulls from the outdrive (350MAG MPI Bravo III).  The pump can only move so much GPH so adding in additional inputs does nothing for flow.

rasbury

that's what I would say also but if you look at the manual, that's what it shows as a typical set up...so you have two 350 motors? Guess they would move that boat along pretty well!

Black_Diamond

Interesting set up you have.  Might look into it more just being curious   The 2x 350's do well!  Even better after I dropped the prop pitch a few years ago (over propped from the factory).  I cruise in the high 20mph range usually at 3,800 rpm.

LaRea

The dual-pickup plumbing is, I guess, for redundancy.  My 342 had it but my 370 (with Merc 496s) does not.

rasbury

It really does not make sense...i am really starting to think I

have a blockage in the out drive..

rasbury

I guess the duplicity is ok, at least you know your going to get enough water from somewhere, like when your plained out, you might miss grabbing enough water from either by it self. I would be pretty sure they are not there on a whim. It states in the manual it needs the two to maintain req'd water flow.

Now then, tries what was suggested above with regard to priming, open the pump to let water flow but did not work for me. So, I stuck a hose down the removed main hose and does that pump suck some water! At just idle, it took all the hose from my house supply without a drop in the bilge. So at least I know , so far, I did not cook the impeller. If I have problems at speed then that's the first place I will check. It ran up to just below the 175 and held there so assumed the thermo is working properly as well....I do see why the muffs that I have can't get enough pressure, the actual outlet for the water is much smaller than the supply line. So hopefully now, with the system all primed up if I put it in the water it will draw properly. I don't think I would trust my muffs to supply enough water, even my fake lake has about a 3/8 actual supply size for the water...maybe with two hoses. May get to test yet this afternoon!

rasbury

no go, would not pull water...guess the pump has something else going on, a leak somewhere. I did not pull the hoses off the back of the pump. Crud. I've read the other posts of problems with new impellers, I think this should have been pretty straight forward repair. But, on the plus side, I am learning the boat. The starter repair was good and the guy does alternators and marine gennys.

Back to the drawing board on the pump.

LaRea

Strange.  Have you looked at the inside of the pump body, to see if it's worn?  Even with a new impeller, a worn pump body will not prime and won't produce enough pressure to cool the engine.

rasbury

well, that's where I am going back to. The motor has only 98 hours on it and it's the heavy duty brass one and not the composite one...it looked fine. When I put the hose directly into the hose that feeds the pump it seemed to be pulling water like crazy.....

Michael T

If the motor only has 98 hours on it and the pump is a new brass one it shouldn't be worn unless you've been anchoring at the beach or over sand bars with engine running! MT 

RWBLACK6

My 2004 ,342, fresh water cooled 6.2,MPI ,Bravo 3  also has dual pick-up. Was told by Al that outdrive pick-up only was not enough .  Hey B.D.: Just wondering; If you had dual pick-up, if you still would have overheated in the middle of Lake Mi when that bag attached to your drive. Interesting? 

Black_Diamond

RW:  good memory on my trash bag pick up!  I would think the dual pick up would eliminate that problem.  So then you have to ask: why do I not have the dual pick up set up if it is needed?

rasbury

Black- if you look in the service manual for this motor, it is not optional- as to why you do not have it would be very good question for Rinker I would think.  I am going to get a coupler and by pass the sea strainer and see if perhaps I have a leak or a crack that is sucking air. I did get down there last night and check all the hoses. It was interesting to note that the drain for the sea strainer was on the back side so not visible at a quick look- it is heavily corroded, when I tried to remove it, it broke. Now the sea strainer is 1/2 full of water so I don't think that is my problem per say, but, it will need to be replaced. I wonder if it has a steel plug in an aluminum housing? For what those cost (looks like the exact replacement is around $300.00, you would think that thing would last forever. Their is corrosion all around the plug, almost looks like a battery connection with corrosion all over it....otherwise, that is my last thing to look at before removing the pump again and starting over. I don't think there is any damage to the pump with the 98 hours and I don't think the fins that broke off and jammed likewise could have bent this piece of brass but we will see...what a pain! I'm so ready to be on the water!!!   

rasbury

ok, well....so I found something suitable to join the hose that goes to the foot to the hose that goes into the pump, fired it up with the muffs on and no water through the motor so something not right with putting the pump back together or toasted the impeller or both, darn, well, at least I know how to take it off. 

Michael T

Good attitude Ras. Now I have to find out what's going on.....don't keep us in suspense too long! MT

rasbury

well, got the whole pump off this time in record time, not to compete with Tiki but I'm thinking some rum may be involved with that number!

I'm a little confused about the discussions of the grooving at  the top and bottom of each end of the pump. I do have some grooves and I do have some corrosion. The surface that the tips of the fins run is nice and smooth, The face side of the pump seems to have a slightly raised section in the middle as to keep the fins off that face, not sure about the other end. Anyway, by the condition of the impeller it looks like age got it- I had the new one but just had not got it done, boat was running fine, no sign of over heating, just bad judgment on my part. Supposedly, this boat only had 98 hours on it- if so, these pumps groove up pretty quickly.

For the chance of that O ring was out of it's place when I put it back together, which I did down in the motor, I'm going to put this back together and fire it up. Tiki mentioned he found a 1/16 spacer of sorts that you can install but seems like it would put more pressure on the impeller to seal it up? Did not get that one completely. So, since I'm getting so good at it, I will use some steel wool to clean things up and put it back together with a new impeller and see what happens.....man this tinkering can be painfull!

Michael T

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LaRea

The wear on your pump isn't terribly bad.  I've seen worse.  But -- engine hours are not a good indicator of pump wear.  It's determined more by how many times the pump was operated in sand or other debris.

If you decide to replace it, consider the Hardin Marine pump.  It has a replaceable wear plate.

http://rinkerboats.vanillaforums.com/discussion/comment/8788#Comment_8788

rasbury

 I would like to install a new pump, just don't want to pay for one. I will clean up and re install, perhaps I can get a season out of it...we'll see this weekend!

rasbury

Hey, also, my pump is "air actuated" and I'll try to attach a doc, but, I broke one of the lines broke while removing...there is a hose the comes off the top that goes to no where and is bent over in half and jammed in place to hold it further up the motor...what's up with that? Can't post a file here apparently...

Dream_Inn

Ras, that may be the hose the water comes out of when using the hand pump (for air actuation).

rasbury

there is no way it would drain unless your supposed to pull the hose down and unfold it....it's not much more than 1/16 in dia. ...will have to do more digging on that system...thanks guys, I do have to get one of those other two drain lines as I could not get it out of the pump and had to cut it, the other pulled out.