496 water circulating pump
#1
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Joined: Jun 2004
Posts: 334
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From: Md
I noticed today that I had some dried-up rusty colored residue sprayed over the front of my 496. Also some on the bilge floor. It looks to have squirted out of a weep hole on the front of the block water pump. Has anyone ever seen this? Why would it be rusty? The engine coolant is only two years old and looks fine. I'm concerned my memorial weekend will be having to change a pump. Woo Hoo.
#3
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Joined: Jul 2011
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From: Ft. Worth TX
so did your AF level go down in the reservoir ?
And how did you mix the AF and water ? Hopefully you used DISTILLED Water for a 50 / 50 mix of Dex Cool and distilled water.
I do have plenty new circ pumps for these 496's with the proper gaskets as well. They are made here in the USA.
And how did you mix the AF and water ? Hopefully you used DISTILLED Water for a 50 / 50 mix of Dex Cool and distilled water.
I do have plenty new circ pumps for these 496's with the proper gaskets as well. They are made here in the USA.
#4
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Joined: Jun 2004
Posts: 334
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From: Md
so did your AF level go down in the reservoir ?
And how did you mix the AF and water ? Hopefully you used DISTILLED Water for a 50 / 50 mix of Dex Cool and distilled water.
I do have plenty new circ pumps for these 496's with the proper gaskets as well. They are made here in the USA.
And how did you mix the AF and water ? Hopefully you used DISTILLED Water for a 50 / 50 mix of Dex Cool and distilled water.
I do have plenty new circ pumps for these 496's with the proper gaskets as well. They are made here in the USA.
I'm going to go ahead and change the pump and I can easily change the coolant at the same time if you think the water may be an issue. I'm going to loose a lot anyway. It will also be a good opportunity to clean the heat exchanger and change the thermostat. My engine temp varies over a wider range than it used to (+/- 20 degrees) when running.
How do I order one of your pumps?
Last edited by NightHawk; 05-13-2018 at 05:14 AM.
#5
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Joined: Jul 2011
Posts: 9,594
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From: Ft. Worth TX
temps swings can be a sign of a bad circ pump I have reported that issue in the past on OSO. When we
had a bad run of these circ pumps
in the pic - the temps swings happened all the time. We seen this from many not just one. Prob not the case whats happened to yours but I would not rule it out either.
How fast are you needing a pump ? And I would install a New T stat as well. Have those to.
had a bad run of these circ pumps

in the pic - the temps swings happened all the time. We seen this from many not just one. Prob not the case whats happened to yours but I would not rule it out either.
How fast are you needing a pump ? And I would install a New T stat as well. Have those to.
Last edited by BUP; 05-13-2018 at 05:08 PM.
#6
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Joined: Jun 2004
Posts: 334
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From: Md
I plan to start disassembly this comming weekend, mostly just to see what all I'll need. I'm going to use this as an opportunity to clean up a lot of stuff. I would need a new pump to put back on by the following weekend.
#8
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From: Ft. Worth TX
Also your spark plugs wires shipping out to you this week. THANK YOU. I was at the marinas last week working on boats as to why I could not ship.
#9
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Joined: Jun 2004
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From: Md
Finally received all the parts to do this job and ready to install the pump. The Merc shop manual says to apply Perfect Seal to the 4 attaching bolt threads. Why would I want to apply gasket sealer to the threads of bolts going into the block?. Anti-seize maybe but gasket sealer? Is it a misprint and they mean the gasket surfaces? They don't mention putting any on the two gaskets.
#10
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Joined: Jun 2004
Posts: 334
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From: Md
Back on the water and running good with no leaks. Engine temps are steady at 160 when running now. Lots of stuff to change with that job.
At least 5 tubes on the heat exchanger were blocked by small pebbles. I had to dislodge them with a .17 caliber rifle cleaning rod (.22 is too fat). I would never have seen them without removing the exchanger, both end caps and looking down each tube. Crossover to water pump seal was also damaged and the retainer screws were seized. That was fun.
At least 5 tubes on the heat exchanger were blocked by small pebbles. I had to dislodge them with a .17 caliber rifle cleaning rod (.22 is too fat). I would never have seen them without removing the exchanger, both end caps and looking down each tube. Crossover to water pump seal was also damaged and the retainer screws were seized. That was fun.



