water pump

[phuggit]

I changed the serpentine belt on my boat this weekend. While the belt was off I checked the idler pulleys and power steering pump to see if they spun freely and w/o slop. When I checked the sea water pump, It was pretty difficult to turn clockwise and wouldn't turn at all counter clockwise.
I've got a 496 and I'm just wondering if that's normal. Seems like that much drag would rob the engine of hp. I also noticed quite a bit of belt dust was around the pulleys. Do I have a bad sea water pump?

[Dr. Eagle]

Originally posted by phuggit
I changed the serpentine belt on my boat this weekend. While the belt was off I checked the idler pulleys and power steering pump to see if they spun freely and w/o slop. When I checked the sea water pump, It was pretty difficult to turn clockwise and wouldn't turn at all counter clockwise.
I've got a 496 and I'm just wondering if that's normal. Seems like that much drag would rob the engine of hp. I also noticed quite a bit of belt dust was around the pulleys. Do I have a bad sea water pump?
Turning the pump backwards = very bad
Depending on how much you may have run the engine out of water, you would be well served to replace the impeller...
Merc water pumps are POS's and pretty much need replacement every year or two... Don't wait till it goes though, best to change annually.

[Just Tool'n]

And when you do replace it, look for missing chunks of rubber!
Then look down stream in the oil cooler, & get them the F*ck out of there!
Your motor will still over heat because of this, trust me, I am speaking from experiance!

[rivercrazy]

It should be relatively hard to turn by hand in the right direction. The pulley is pretty small. Change the impeller anyway. Mine was toast at 90 hours....
And its pretty normal for the serpentine belt to fling rubber dust on the back seat carpet. But I carry a spare! :D

[Dr. Eagle]

Originally posted by Just Tool'n
Your motor will still over heat because of this, trust me, I am speaking from experiance!
Me too. My last one went and there wasn't a vane left on it at 90 hours. If it is all there, you don't need to go fishing in the oil cooler. Unfortunately, I ended up pulling out rubber chunks for some time.
If your belt needs replacing, I bet money your impeller does too...:eek:

[Trash]

Its kind of funny. I had almost the opposite experience with my pump. Over 500 hours and 8 years of use before it let go. However, likes others I had chunks of impeller all over the cooling system. But instead of overheating some pieces would lodge in the thermostat and overcool the engine.
Either way get the crap out.
If you did rotate the pump 'backwards' there is a good chance you damaged some of the impeller vanes. When the impeller is installed it is given a rotational twist in one direction so all the vanes 'fold over'. If you spun the pump the opposite direction the vanes would want to reverse direction, buckle and fail within the confines of the pump housing. Tough to describe without a good picture.

[phuggit]

Thanx for the info. Luckily I didn't spin it backwards, but I'm going to change it out anyways.