Is a water pump, A water pump???

[RJ's Addiction]

Hey guys. I got merc 4.6's in my boat. I spun a

impeller two seasons ago. I had the impeller and

the water pump replaced on the port engine. I ran

the boat no more than 20 hours and the same thing

happens. Smoked another impeller on the same engine.

Now. The question is... Are marine water pumps the same as one

you put on a truck.The marine water pump is $170.00 and the "auto

water pump" is $40.00 They look the same when you put them

side by side and all the holes match up. To replace the impeller

you have to pull the boat out of the water and drop the lower unit

and with it being a

30 footer it gets expensive to keep pulling it out.

Thanks guys for your help.

Randy

[ray koziatek]

huh ,water pump on moter or impeller in out drive sounds like your talking about doing both you can smoke the impeller in the out drive in seconds running it dry im talking dont even crank and start for a sec or two unless the thing is wet kinda a old timers marina scam to change a few,as far as motor water pump biggest diff that i could see was the heater hose outlet is solid casting on boat (no heater or hose) and drilled on auto if you didnt do the above id be right there when they pull the old one if the impeller is melted looking in the pump walls id pull out my digital take some photos and ask to see the owner , ,,,pm me if ya got some questions

[L&M]

huh ,water pump on moter or impeller in out drive sounds like your talking about doing both you can smoke the impeller in the out drive in seconds running it dry im talking dont even crank and start for a sec or two unless the thing is wet kinda a old timers marina scam to change a few,as far as motor water pump biggest diff that i could see was the heater hose outlet is solid casting on boat (no heater or hose) and drilled on auto if you didnt do the above id be right there when they pull the old one if the impeller is melted looking in the pump walls id pull out my digital take some photos and ask to see the owner , ,,,pm me if ya got some questions

RJ: There is a difference and I'm not sure if your talking circulator pump, or raw water pump, but I'm assuming you mean raw water pump ( in Outdrive). Unless your in salt water the engine circulating pump seldom goes bad unless a seal starts leaking or a bearing goes & they are both usually related. The difference between automotive and marine is not the casting but different seals, bearings and a stainless steel impeller plate to help combat salt water corrosion. But as Ray said you can not run the engine out of water unless you have an adequate water supply to it. There are more reasons why the raw water impeller would fail after that short of time if you want, pm me & I'll run a few things by ya.