Water circulation pump for OMC 5.7 Cobra

[Donzi GT250]

My water circulation pump on my 1989 OMC 5.7 Cobra is making noise and I am going to replace it.
I have a choice between the OEM volvo penta pump for $175.00 or the sierra aftermaket replacement pump for $88.00.
My question should I go with the sierra pump or should I go with the OEM volvo penta pump?
Is the sierra pump of inferior quality and maybe not a direct replacement?
Here are tha part numbers for each.
OEM volvo penta # 3853850
Sierra aftermarket # 18-3583
Any opinions would be appreciated.

 

[bruceb58]

Re: Water circulation pump for OMC 5.7 Cobra

Personally, I have gone with aftermarket pumps and have been fine and I am one that usually always goes OEM.

 

[Lou C]

Re: Water circulation pump for OMC 5.7 Cobra

I just put a Sierra one on my old 88 4.3 this fall, it was a good price and fit fine. The old one was also making noise after 22 years of use. I also have a Sierra starter on mine that works just fine...

 

[brewu240]

Re: Water circulation pump for OMC 5.7 Cobra

My 1989 5.7 Cobra OMC pump was leaking and also making noise. I changed both belts which quieted the noise - and purchased the Sierra aftermarket part to put on, it should be here tomorrow. Did you end up going with Sierra? Was it difficult putting it on?

 

[Lou C]

Re: Water circulation pump for OMC 5.7 Cobra

It's an easy job really, the only snag can be getting the old pulley off the mount, spray where the mounting bolts go through the pulley with PB Blaster, let it sit, then tap it off with a block of wood and a hammer...Also, take note of how the accessory brackets are bolted on, because you have to remove one or both of them, they share mounting points with the pump. I put OMC gasket sealer on the new gaskets....