I just replaced the water pump on my '96 Accord EX 2.2L (F22B1) engine. I was shocked to find that all seven water pump impeller blades had snapped off and were gone.

I think this explains my persistent overheating problems

Has anyone else experienced missing impleller blades? Any theories about why this happened?

And most importantly: Any guesses about where the impeller blades are now?

 

i had it happen to a friend once, running mostly water and tried to start car when it was freezing.

best guess is the blades are either just sitting in your hard water pipe or in the bottom of your block (waterjackets)

 

did they break off, or did they wear/corrode away?

 

I'm sure the timing belt loved cranking the water pump through that mess.

 

I havent seen this on a honda but multiple times on ford / chevy -- The glycol (antifreeze agent) in coolant does not wear out but the additives such as waterpump lubricants and rust inhibitors do begin to fail as early as 18 months -- When the PH of the coolant changes the coolant can actually conduct electricity-- it is this current plus the lack of rust inhibitors than can literally eat away at any metal in the engine -- since most impeller blades on a water pump are light grade stamped metal they are some of the first areas to show a concern -- but don't forget -- head gaskets also have metal in them -- if the coolant you found in the system was rust brown in color -- look for potential other concerns to show up like leaking freeze plugs and even -- sorry -- head gasket concerns-- This electrical flow can actually be tested with an analog volt meter -- drop one lead into the coolant and the other to the proper battery terminal -- I have seen 4-5-6 volt readings shown with "old" coolant.... Save yourself future trouble -- change the coolant regularly -- at least every 2 years .. even the extended life coolant fails to provide protection as advertised...

 

The blades looked like they had broken off to me. There was a clean straight line at the break points and all seven blades had broken where the individual spokes/blades take a 90 degree bend upwards.

It looked to me like there was some corrosion. Enough to weaken the impeller but it didn't look like the blades had corroded away. I saw a propeller on a boat recently that had been corroded away by electrolysis. This looked different.

 

I hadn't thought of this explanation. I like it.

It doesn't freeze often here in Central Texas and I try to keep (mostly) antifreeze in the cooling system. But I'm the third owner of this car and I don't know where it lived in the past, or if it was cared for well.

On second thought, judging by the worn piston rings and the amount of work I've had to do on the engine I'd guess that it was not maintained well.

 

I didn't know that coolant degraded so quickly. I'll keep an eye on it. And I'm looking forward to trying the voltmeter trick. Thanks.