Mercruiser 350 waterpump

I don't to start a bashing war because overall this engine has been fine.But, the original waterpump was replaced at approx. 60 hrs. Now at 200 hrs. I need another one. Anyone have this problem? I know there was a serpentine belt issue that year, 2002. So I am wondering any ideas? Thanks

ive gone 157hrs on an o5 with only 2 problems so far,an exhaust gasket has gone twice,on the same side. not sure why, but, no issues with waterpump

are you talking about the water circulating pump or the raw water pump?
If its just the raw water pump that is normal impellers should be replaced.

I just replaced the circulating pump in my sanger, the main feed hose broke down internally and sent metal chunks into my circulating pump destroying it. Ive replaced this hose with one that does not have a wire lining. This happened at 300hrs mercruiser black scorpion.

I have a 2002 Merc also and haven't had a problem with the raw water or circulation pump at all. What is actually going wrong on yours?

I did lose a fuel pump, but I think that was due to the fuel boiling in the lines (i.e vapour lock). It was fixed by the dealer. They also added a boost pump on the engine, which I believe is now standard on all Mercury EFI engines.

Trash

Nate and Trash, the pump I am having problems with is the one opposite the alternator, not the one mounted below the alternator. In my limited mechanical knowledge I am assuming that is the circ. pump. Anyway when I started the motor heard a squeal , motor running, belt not moving. Loosened belt, alternator and the "other pump" [raw?], spun fine. The circ. pump was really hard to turn. I guess someone could have crazy luck and get two bad pumps in a row. My concern is that the tension or the belt ate the pumps up. anyone else have this problem?

Mercruiser offers two styles of pumps a rebuilt and a new one. You can also use Volvo pumps. If you had a shop install it the last time, im willing to bet they used a reman. In my opinion remans should only be used when its the only option.


This time around replace the impellar and the circulating pump and all new hoses. Make sure to buy a new water pump. A miss aligned belt could possibly wear out the bearing but I doubt its the problem.

(Message edited by norcalmalibu on April 11, 2007)

I have a brand new water pump from skidim that I don't need. I bought it last year to replace a bad one and ended up getting one locally before it came in. I'll sell it for $70 + shipping. This is the model http://www.skidim.com/prodinfo.asp?number=WP-2232MN

Thanks Kevin, but the boat is at the dealer now.

Dale, how did you know you had gasket problems. Noises, overheating?

the noise from the motor got slowly louder and louder as time went on and was a distinct exhaust leak sound on right side of motor. i assumed a gasket, had a mechanic fix the first one, am in process of doing this time myself now the warranty is over.

I had exhaust gaskets on both sides go bad at less than 100 hrs.They looked like they were pinched and damaged during assembly and over time got worse.

My motor is an 06. I wonder if they fixed the problem. I don't notice any noises around the manifolds. I have heard of several problems with 05's and exhaust leaks around the manifold area.

sounds like a bad impeller, no big deal normal wear and tear. i have an 01 merc 377 super scorpion with 385 hours. any debris in the water you are boating in is sucked in through that pump, that grate on the bottom of your boat stops the biggest pcs but stuff still goes into the pump and wears out the impeller...sometimes sooner sometimes later. you can install a sherwood inline screen filter to stop more debris from going through and protect the impeller. they will still crack and break due to age and the job they are required to do...

I recently posted about my water pump going bad. I really don't think that a pump going bad is really worth posting about. The only reason I even did it is because One pump had to be replaced at 60 hrs. That, coupled with the serpentine belt issue Mercruiser had in 2002 had me a little concerned. Anyway in fairness to Mercury it was only a bad impeller, the pump was fine. This impeller failed right at 100 hrs. So, I thank God I didn't come out bashing the dealer, boat, Mercruiser etc.. Thanks for the help.