Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it hot?

[IcantDo55]

I'm having cooling issues, this weekend I went to get the boat ready for the season.

Changed the plugs, wires, cap, rotor, oil, filter and greased it up.

Had intermittent starting problems last year so installed a relay and starter motor.

Started fine on muffs, let it run for and hour or so and the temperature gauge just kept rising past the usual 140*, when it got to 180* and water coming out seemed kinda steamy I shut here down. Pulled the thermostat and it was gumed up so replaced that with another 140*. Started it again same thing after 20 minutes it got hot again.

So I puled the 5/8" hose from the out drive to the thermostat housing and put the outdrive in a large bucket of water. (no muffs) Started it and ran it for a minute or two and nothing came out of hose, so I figured it was a problem with the raw water pump. Its not that old, think I put it in there two or three years ago and this boat sees very little use. Maybe hit the water 5 times in 3 years.

Pulled the lower unit and it all looks just fine, except all the gaskets in there that tore up upon removal. So I'll be replacing it just because I'm in there.

Do I get the Mercruiser unit for $125 or the GLM one for $90?

And, what is wrong with my motor? Why is it still over heating? After I replace the raw water pump what do I check next?

Its a 1995 3.0LX with alpha 1 genII in a 19' seapro.

 

[cooter2506]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Both will work. Useed both on my drive before. But I do change mine yearly and put maybe 40hrs a yr on it. Change it and see if it fixes it. If not maybe you have a restrictino at the power steering cooler. remove the line from ht eout drive to the cooler and see how much flow you have. But dont run engine more than a few seconds that way. If it is good and still over heating you definitely have a restriction somewhere. PS cooler or even exhaust manifolds or risers.

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Both will work. Useed both on my drive before. But I do change mine yearly and put maybe 40hrs a yr on it. Change it and see if it fixes it. If not maybe you have a restrictino at the power steering cooler. remove the line from ht eout drive to the cooler and see how much flow you have. But dont run engine more than a few seconds that way. If it is good and still over heating you definitely have a restriction somewhere. PS cooler or even exhaust manifolds or risers.

It does not have power steering and the riser is less than a year old. Any other ideas?

 

[POINTER94]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Do you have an oil cooler on her? Check and see if there are chunks of an old impeller creating a blockage. Then there is the obvious thermostat issues.

 

[cooter2506]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Change the water pump housing and all and see what happens. Like I said check your water output from impeller by removing water inlet and seeing flow.

 

[Bt Doctur]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Really should use muffs unless the bucket comes about 10 inches above the cavitation plate .Any less and you melted the impeller

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Do you have an oil cooler on her? Check and see if there are chunks of an old impeller creating a blockage. Then there is the obvious thermostat issues.

No oil cooler.

Old impeller? I was in great shape when I took it out today, so good I considered reusing it. Its only 2 years old.

I changed thermostat toady and admittedly the old one was trashed, the motor did the same over heating thing with the new thermostat.

The boat ran great last fall, no issues so I doubt it was parts of any old impeller from over 4 yeas ago, the two I have put on there came back out in once piece.

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Really should use muffs unless the bucket comes about 10 inches above the cavitation plate .Any less and you melted the impeller

Hmmm, bucket just came up to the cavitation plate, guess I was lucky because the impeller looks great.

Why it need to be so high? Though it just had to cover the holes in the lower unit.

 

[Bt Doctur]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Either you missed something doing the water pump or the water is not making it thru the hose. Pull the drive and use 1/2 of a washing machine hose stuck in the water inlet hole in the transom end,
If motor is fine now, it`s a drive issue.
If motor is hot, it`s a motor issue

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Either you missed something doing the water pump or the water is not making it thru the hose. Pull the drive and use 1/2 of a washing machine hose stuck in the water inlet hole in the transom end,
If motor is fine now, it`s a drive issue.
If motor is hot, it`s a motor issue

Hu? Whats a "1/2 of a washing machine hose"?

Put that in the hose in the hole that #19 would normally connect to and run it? It would have not outdrive oil? ]

Sorry I might be dumb.

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

 

[Bt Doctur]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

The hole on the left.
got a spare pump kit for less.

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Thanks for the info BT, but I don't want to take the rest of the out drive off if I don't have to. Would that not be the same as feeding water in the rubber hose that feeds the thermostat housing?

thanks

 

[boatguya1]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Thanks for the info BT, but I don't want to take the rest of the out drive off if I don't have to. Would that not be the same as feeding water in the rubber hose that feeds the thermostat housing?

thanks

That would bypass the possible blockage points mentionrd above. I'd stay away from running it with the lower off/no oil in the upper. There is a ridge on the top/bottom of the impeller. It is circular right around the hole for the shaft. It should come up to a "pointy" edge at the top of the ridge. This seals against the housing. If it is worn the imp is no good.

James

 

[hoot]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

what flow rate did you have on the muffs while running? the water flow needs to be 'brisk' thru the hose. and an impeller might look ok, but it may not be pushing water up to the main pump.

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

Ok I got a complete water pump kit and am trying to figure out some stuff. It comes with two identical o-rings (#30). I see on the diagram that go above the pump output fine but do they just both sit on the top of the pump? I also see above the water pump there is a coupler (#29) that did not come with the COMPLETE kit. If you look up that coupler to buy it, it listed with two o-rings? Are these the o-rings included in the kit? Do I have to somehow remove the coupler and replace the internal o-rings? Sticking my finger in the coupler I feel o-rings. How does that coupler come out?

After some searching I have seen a few posts talking about a tool needed to aline something that is included in rebuild kit, I got no such tool and don't know what there talking about.

Thanks for your help!

 

[IcantDo55]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

A couple of things, first is that running on muffs is ok but... unless you have a lot of water pressure in your garden hose you may not be supplying enough water. Most times a garden hose is ok for an idle speed but at higher RPMs its not.

Second, running your raw water pump dry, even for a few seconds can mess up the impellor or worse, the housing. Don't do it.

They make a small kit/valve that yoiu can put in the water line between the outdrive and the engine and I am of the opinion every boat should have it installed. With it troubleshooting cooling problems is MUCH easier.

I agree.

Any answers on question in post #16?

 

[boatguya1]

Re: Should I spring for the Mercruiser Water pump or the cheeper GLM? Any why is it h

The o-rings go in the coupler (#29) and you should be able to just grab the coupler and pull it off the tube in the upper unit. The guide tube #31 should also slide right off.

James