Problem with 94 Alpha 1 Gen 2 Water Pump

[Bry21317]

Ok,
So I have been having issues with my engine overheating and I redid the water pump again. I got it all put back together with new seals and all.

The engine still got up to 175. The engine is a 94 Mercruiser 305 with an Alpha 1 Gen 2 drive. The thermostat is brand new, and I tested it in a pot of hot water and it opened at the right temp. The thermostat is a Stainless steel Quicksilver brand with a temp of 140. I got this directly from the Dealer.

Before my engine would always run right at 165 on the high side. The impeller was not bad, and did not have any broken off pieces.

Here is what I am running into. I have thru hull exhaust with no Exhaust or any way for the exhaust or water to go through the Prop shaft. What I just found after putting the lower unit back on and everything being right and triple checking it. There is water leaking somewhere, as it is coming out the prop shaft. So it has to be leaking from somewhere around the water pump.

Here is what I replaced:
1) Water Pump Housing
2) Impeller
3) Gasket on the bottom of the Metal Plate under Water Pump Housing
4) Metal Plate below Housing
5) Gasket between Metal housing and Metal Plate
6) Face Seal on top of Water Pump Housing
7) Water tube plastic fittings and new o-rings for Housing side of Water tube
8)Rubber Filler Plug as described below and installed with the gap under the Water pump drain hole. The rounded lip sticks up making a open space under the drain hole
9) I tightened all the bolts tight, I do not have a torque wrench. Could this have caused the problem? Can you tighten them TOO tight?

Here is a picture of how I put the Rubber dam in.

Here is a picture of ALL of the Parts that I replaced with NEW Parts:

I put Perfect Seal below the (A)Gasket below and on the bottom of (B) the metal Plate, as stated in the Mercruiser Manual, here.

Please tell me what you think is the problem. I really do not want to have to do this more than one more time.

Bryan

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

How about the water hose between the drive and transom shield. Is it kinked or the flow blocked to the engine.
Have you pulled the risers and checked the water passages for blockage?
Have you used an IR temp gun and actually verified there is a rise in temp? Seen many a gauge and/or sender go bad.

 

[ziggy]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Can you tighten them TOO tight?

i think so. distorting the waterpump houseing perhaps.... pretty low torque on them bolts too. 60 in. lbs.
that could answer this idea too..

There is water leaking somewhere, as it is coming out the prop shaft. So it has to be leaking from somewhere around the water pump.

though i do hope ya mean thru the prop hub, not prop shaft.....

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
I know that you hate me by now. I promise that once I get this fixed, I will leave you alone.

How about the water hose between the drive and transom shield. Is it kinked or the flow blocked to the engine.

From what I can see up there with a flashlight, I do not see any kinks.

Have you pulled the risers and checked the water passages for blockage?

No, I have not pulled the Risers. The water is flowing out the Thru Hull Exhaust good. The risers are staying cool.

Have you used an IR temp gun and actually verified there is a rise in temp? Seen many a gauge and/or sender go bad.

Yes, I did hit the the thermostat housing where the Sender is, and it is running the temp that it shows on the Gauge. I did check this.

This time it took it about 15 minutes of running at 1k to get up to the 175, before it would only take it about 5 minutes or less. Befor it would also get higher than 175, it would go up to around 190 or a little over. So there was an improvement. The only thing is, something has to be wrong in the pump, to allow water to slowly flow, but its a pretty good amount of water that is coming out of the Prop Shaft. This should not be as nothing comes out of my prop, exhaust or water at all when it is working right.

There has to be something that is leaking between the lower and the upper that is then allowing the water to drain out that cavity. The problem is there is no easy way to see this or make it occur when the lower is off the boat.

I really am sorry Don. I know I am driving you crazy, I am sure, I am not the only one either. I do greatly apreciate all your help.

Tell me what kind of beer you drink and I will send it your way!

There is water leaking somewhere, as it is coming out the prop shaft. So it has to be leaking from somewhere around the water pump.

though i do hope ya mean thru the prop hub, not prop shaft.....
__________________

Yes, this is what I mean through the Prop Hub, sorry about that.


Bryan

 

[JustJason]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

you haven't got clear hose hooked up yet do you...... didn't i tell ya to do that like 3 weeks ago?

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
I know that you hate me by now. I promise that once I get this fixed, I will leave you alone.

Why, what did you do to cause me to hate you????? If you did, trust me, I would remember. Plus, I wouldn't try to help you any more if I hated you.

If all I did was get a little short with you, Sorry, what can I say, that's just me.

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
I did not mean it "seriuously". I was actually joking about it. I meant that it was being a pain in my a** and I feel like I am to you. Not from anything you have said at all, but that it is driving me nuts.

Jason,
I did get a hose, but it was the wrong size, the size I got was over an inch, and thought it should fit fine, but it did not. So I went ahead and pulled the lower unit off and found a few pieces that were not right, and some missing items from the Mechanic. So I redid it all again myself, making sure that everything was perfect, well Something is not right.

I have a feeling that it might be that I torqued the bolts to tight on the water pump housing, would this cause it to leak? As I am now getting water leaking down through the prop, which it should have no way to get there, other than leaking out the pump.

I will do the Clear hose for sure. I will get it at work tomorrow and hook it up, if I get a chance in the evening.

There is an amount of water coming out of the prop, like when you would turn your hose on about 1/4 pressure. So it is quite a bit of water. The water is flowing out the exhaust pipes more than it did before though, so it did help, just has not yet fixed the problem. I ran it about 20 minutes and it did not climb over 175, where as before it would climb over 175 in about 5 minutes. So I think this is where the problem lies, and I think that once I get it right, it will be working again.

Bryan

 

[JustJason]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

do you have check balls in the tstat housing in your motor?

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

No check balls on my Tstat housing, I have the newer design with the plastic spacer. Also just out here in the garage looking at the housing I pulled off, and replaced with a new one. It looks like on the larger hole gasket, the one above the metal plate, the is between the housing and the plate, it had sealant around it at one point. I did not add any sealent to this gasket, as it did not say to do so in the Merc Manual, if it did I missed this. This is the gasket that has the little bead of what looks like some type of silicone molded into the gasket.

Is this what I did wrong?

Bryan

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

You have a Gen II drive, with a SS water pump housing. You can't overtorque them and cause a problem (other than broken bolts).
There is something about the gen II that caused a slightly higher temp, but for the life of me, I can't remember it right now. When I do. Trust me, I will tell you.

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
You are correct, in that I have the SS housing. I did notice, now that I replay every inch of it in my mind, that there was a little curvurture in the middle of the housing, after looking at the old one, where I had torqued the bolts down, causing this to happen between the two bolts on either side.

Do you need to put perfect seal on the Top gasket that I mentioned above? I did not do this.

Bryan

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

No, you don't need perfect seal. Yes, you might notice a little curvature in the housing. It does make contact with the impeller on both sides, and there is the whole hub of the impeller that must be compressed.
But I did remember (after a few minutes of watching 'Meeeeennnnnnn" on TV.
Make sure the impeller is going the right way. unlike the older drives, the vanes will not flip over and go the right direction.
When you are looking at the impeller as installed, (from above the upper) it should be shaped like this.

If not, turn it around. It won't pump as much water if installed backwards.

 

[JustJason]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

huh???? the vanes flip over automatically on anything before alpha gen 2's??????
And i'll this time i've been makine sure i was spinning that driveshaft clockwise....

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
I think that might be it. I just looked at the old one I pulled out and it is the opposite of that, what the mechanic had put in. I did it the same as that one, I am pretty sure. The veins are going the other way.

Thanks,
Bryan

 

[JustJason]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

if your facing the rear of the drive... so that the propeller would be closer to you and the nose and the lower unit if further away... you need to spin the drive shaft clockwise as you press the waterpump housing down. It usually helps if you get the cover on half way and then double check all the vains.

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

I think that might be it. I just looked at the old one I pulled out and it is the opposite of that, what the mechanic had put in.

Turn it over, and it will look like it was in the right direction.

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
Here is a picture of how it was installed. This is the old pump that I pulled it out and copied to make sure it was the same. I think it is correct now that I look at it again. My brain was not working last night.

Am I correct in this?

Bryan

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

That impeller is in the correct direction.

 

[Don S]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

In this picture, are you sure you put gasket C on correctly. The gasket is NOT symetrical, and if you put it on upside down, it will not seal on the pump housing.

 

[Bry21317]

Re: Problem with 94 Alpha 1 Gen 2 Water Pump

Don,
I read that in the manual. I am pretty sure that I did put it on right, as the screw holes would not line up either, right?

I did put it so that the small blue line of Silicone on top of the gasket was facing up to the bottom of the water pump housing.

This is correct right?

This is what it looked like from what I got in the manual.

Also the Rubber damn is correct right? How I installed it, it has the Lip facing up in the back? The mechanic had this installed upside down, the lip was facing down, so under the weep hole was a flat rubber surface.

Bryan