overheat?

[magregor22]

I took my boat out for a test drive(18' sangster with a 470 mercruiser) it seemed like it was running way to hot even though the temp guage said 145 i couln't touch the exhaust or intake manifold. even the valve covers, oil filter and side of the block were all too hot to be able to touch. I came home on the kicker and pulled the bottom of the leg to check the water pump. as soon as i pulled the drain plug clear water came out(about a cup full)and then the gearlube behind it. They didn't seem to be mixing yet. the housing that contains the water pump is severely blistered and the plastic pipe that is around the copper tube that goes up from the pump is completey melted. when I took the pump apart the impeller does not seem to be in bad shape, granted the fins are a little warped but it looks like it would of pumped water. my question is what blistered the plastic pump housing? the boat has never been run out of the water without the garden hose hooked up to the ears. i am thinking maybe i have a blockage some where in the cooling system and the blistering is from the hot exhaust? anybody have any thoughts? i am scared of putting a waterpump rebuild kit in just to have the engine fail ten miles out in the ocean. i was going to take it in to get fixed but being spring there is a two month waiting list here. thanks gary

 

[Haut Medoc]

Re: overheat?

I don't know the cause, but I would replace the water pump {they are not to expensive], pressure test it and if it passes, fill it up and see how it re-acts when in the water.

 

[magregor22]

Re: overheat?

i am going to put a pump rebuild kit in,just wondering if anybody has seen the housing blister like that without the impeller melting down and why this would happen.

 

[Bondo]

Re: overheat?

You've got it figure out.......<br /><br />No Water...........All Exhaust..........<br /><br />Flush the Water Flow Path to make Sure there's No Restrictions........<br />Back-Flush it from the H/E Backwards......<br />Make Sure the Elbow/Riser isn't Plugged....

 

[magregor22]

Re: overheat?

Thanks Bondo, I will do that and post what I found

 

[cc lancer]

Re: overheat?

the housing that contains the water pump is severely blistered and the plastic pipe that is around the copper tube that goes up from the pump is complete melted.<br /><br />At the top of the tube<br />at the top of the outdrive is a flange with 4 SS bolts in it.....it is also melted. You will probably have to get a flashlight to see the water inlet I am talking about. Back-flush as Bondo said. How old is the impeller? My experience is they do not live as long in salt as in fresh water. Good Luck!!!

 

[magregor22]

Re: overheat?

cc lancer,the flange your talking about is also severely burned. I am having a hard time removing it because the plastic has melted to the screws. I am trying to remove the top part of the leg so I can flip it upside down to work on it. The manual said to remove the six 5/8 nuts and the rams and it will just pop off but no luck so far. I got it to come out about a 1/4 inch and thats it.<br /><br />The impeller is at least two years old because thats when I bought the boat. the guy who sold it to me said he changed it a couple of months before he sold it to me.<br /><br />last year I developed a leak it the heat exchanger and the coolant run out the leg and aloud the engine to get fairly hot, maybe that was the start of the problem.<br /><br />I am going to flush the system on both sides of the cooling and in both directions.

 

[Bondo]

Re: overheat?

Go Easy on that piece in the upperunit.......<br /><br />The Screws are Frozen in the basemetal,... Not so much the Plastic........<br /><br />Good Luck,.... You're Going to Need It........... <br /><br />Ziggy, or 1 of the Guys has a thread bouncing around on page 1 about the Same Exact Issue.......... Look for it.......

 

[magregor22]

Re: overheat?

Thanks,Ill clean off the plastic around the bolt heads with a dremel and use a impact to free the stainless bolts. I can just imagine what fun it would be if thise stainless bolts break. Two different metals aluminum verses stainless causeing the bolts to freeze?

 

[tommays]

Re: overheat?

dont use a lot of force those heads will snap very easy <br /><br />let some pb,liquid wrench what ever soak in anything can be drilled out but this is one to avoide at all costs <br /><br />tommays

 

[magregor22]

Re: overheat?

I took the upper unit off and the bellow, ujoints and bearing are all full of a slimy mixture of oil and water. There is a small amount of rust on the drive shaft but the u-joints are still tight. Pumped some grese and no water came out.The upper crown and pinion look good but the small bearing at the top of the upper unit doesen't spin smoothly,so I better change it. I am starting to wonder if it's time to hire a profesional to look this over.

 

[Haut Medoc]

Re: overheat?

Yes, you have serious problems.If you have water in the bellows, its not good.Drain the drive & see if you have water there. If you do your out drive needs to be dis-asembled & at very least resealed. If you don't, then the yoke seal should be done at the very least. New gimbal bearing & most likely U- joint bellows as well. The prognosis is not good. If you can afford the $, take it in. It a'int gonna be cheap....sorry-J

 

[trog100]

Re: overheat?

"I am starting to wonder if it's time to hire a profesional to look this over."<br /><br />yes it probably is.. u ran the engine without adequate water flow to keep it cool.. the gauge was giving a false reading cos it reads water temp.. no water the gauge gives a false reading.. that 145 was meaningless the engine got way hotter than that and could have suffered damage..<br /><br />now u are finding other unconnected problems as well..<br /><br />time to call in the pro i recon.. <br /><br />trog100

 

[magregor22]

Re: overheat?

Trog, the water temp guage is on the closed or freshwater side so it would of had water even when the seawater side didn't. It must be a faulty guage.But the fact that i have gearlube and water mixture in the bellows makes me think i have a oil seal gone and that means taking the leg apart and according to the manual that requires special tools and making sure the backlash is set among other tricks. i guess I'm lucky to find this all out before it blew up(probably 20 miles from shore).I'm going to find someone to come over and help me taht knows all the little tricks. thanks for the advice, you guys are greatly appreciated.<br />Gary

 

[achris]

Re: overheat?

HJ,<br /><br />The oil in the bellows usually comes from the seal in the front of the top box of the leg. You'll probably find that the shaft has a nice deep groove in it to, making it necessary to replace it too. At this point I would conside a 'new' top box, like from iBoats. That way you'll miss out on all the pus and pain of replacing the water pocket cover too.<br /><br />Chris............

 

[magregor22]

Re: overheat?

I saw the grove in the shaft.I guess I could still get a core for mine and get a rebuid.The kids didn't really need to go to collage.

 

[qystan]

Re: overheat?

No water flow will disintegrate the impeller, but yours is intact.<br /><br />Possibility that the burn/melt/blistering are from the exhaust that is not getting the cooling water.<br /><br />Is your FWC a full or partial system? It may be the exhausts are clogged, blocking water flow, in turn causing the heat to melt the pump and parts. Impeller is ok as it is still running in water, the heat is external to the impeller.<br /><br />Water in the drive, I believe its a separate unrelated problem that you happen to discover while trouble shooting this. Do check the bellow for tear.

 

[magregor22]

Re: overheat?

Qystan, i believe you are correct. I think my FWC is a full system. The Seawater side flows from the Impeller in the leg through the old voltage regulator, then through the heat exchanger and finally out the exhaust elbow. Everything else is in the closed system.<br />The fact that there is contamination in the upper drive I think is unrelated.

 

[tommays]

Re: overheat?

<br /> http://www.sterndrive.cc/se106-sterndrive/se106.htm <br /><br /><br />at 1195 dollars for a compleat drive you wont get to far into your drive without passing that very fast<br /><br />the big thing to fix is the leaking bellows which is the root cause of the drive damage<br /><br />tommays

 

[trog100]

Re: overheat?

sorry Halibut Junkie.. i assumed raw water cooling.. forget my comments about possible engine damage and stuff.. as long as the closed part of the system had water in it.. it would be okay.. my mistake..<br /><br />trog100