Symptoms of engine water pump being bad?

[Fordiesel69]

I had the outdrive impeller redone and still think I am overheating. Any idea how to check the engine pump before I have to yank it off for an inspection?

1974' Mercruiser 120HP 4 CYL

 

[bruceb58]

Re: Symptoms of engine water pump being bad?

Unless it is leaking, they don't go bad in that way. How hot is your riser getting? if it is getting hot, you have a flow problem. The engine mounted pump just circulates the water within the engine. Check your thermostat? Check the temp with an IR gun to determine that you are actually as hot as the guage says you are?

 

[Fordiesel69]

Re: Symptoms of engine water pump being bad?

The riser elbow was not very hot at all and neither was the intake/exhaust manifold. But the block and head could not be touched comfortably.

BTW, what temp should it be running on a I/R temp gun?

 

[bruceb58]

Re: Symptoms of engine water pump being bad?

Shouldn't be any higher than 160 measuring at the area where the temp sender is.

 

[Stanp1]

Re: Symptoms of engine water pump being bad?

An Infrared Temp gun is cheap to buy at Habor Freight or a Auto parts store. Never trust your temp gauge. The fact that you can touch your riser is a good indication she's cooling ok. The engine water pump is all or nothing. If it leaks its no good. But get the gun, its great insurance, its accurate, and you can test the temp on any part of the engine. I would expect the heads and block to be too hot to touch.

 

[bds85466]

Re: Symptoms of engine water pump being bad?

what is it that makes you believe you are still overheating?

 

[Fordiesel69]

Re: Symptoms of engine water pump being bad?

what is it that makes you believe you are still overheating?

Factory guage is 1/32" of an inch from going into the red zone, and I can smell oil burning from the valve cover gasket. On a car it is normal, for a boat, I am not sure it should get hot enough to make a smell like that.

The intake and exhaust appear to be the same manifold, so how hot should that be?

I bought a cheap autozone 100-250 degree temp guage and will thread that in where my factory sender is. I will also try to borrow a friends l/R thermometer.

I removed the engine pump and it looks fine, however there is rub scars on the cylinder sleeve that shows a water pump did rub at one time. I hope that is not going to spell compression leak later down the road, hopefully the cylinders are thick.

 

[Fordiesel69]

Re: Symptoms of engine water pump being bad?

Anybody have a clue what readings I should be getting? In the temp port and with the I/R gun?

 

[zbnutcase]

Re: Symptoms of engine water pump being bad?

Its not uncommon for the circ pump impeller to rub on the cyl block, the walls are plenty thick, wouldn't worry about it. 'nutcase

 

[Knightgang]

Re: Symptoms of engine water pump being bad?

Ford, if you are concerned about the slight rubbing by the pump impeller, when you reinstall it, use a thicker gasket to gain a slight bit of standoff....

 

[Fordiesel69]

Re: Symptoms of engine water pump being bad?

The impeller is no longer rubbing, but it was at one time. Im sure its on its 2nd or 3rd water pump since 1974. I thought it looked original until I saw the tag on it and the silicone over top of the old gasket. Hacks...............

 

[Fordiesel69]

Re: Symptoms of engine water pump being bad?

Problem turned out to be a faulty new t-stat. Another new one fixed the overheating.

As for the rubbing, I have no idea how to specify a thicker gasket, nobody lists the thickness. Can I just install 2 to space it out a little?