[John E Davies]

This is a pic of the old and new water pumps for a 98 Outback:

Discussion thread: .... Bought a Subaru with history of overheating : Justrolledintotheshop

Well, I guess this is just one of many reasons.......

John Davies
Spokane WA USA

 

[dlo13]

I read once that running with distilled water and an additive provides better cooling than any coolant.

 

[Saint J VT]

Man, that looks like those fins are still there, just all bent together with pliers. Do you suppose someone made the "overheating-engine" happen on purpose?

Why would someone bend the impeller blades in like that? They do appear to be intact, just bent inwardly, is this false? Are they really worn that much?

 

[Novablue]

Man, that looks like those fins are still there, just all bent together with pliers. Do you suppose someone made the "overheating-engine" happen on purpose?

Why would someone bend the impeller blades in like that? They do appear to be intact, just bent inwardly, is this false? Are they really worn that much?

My car uses heavy water.

 

[John E Davies]

Man, that looks like those fins are still there, just all bent together with pliers. Do you suppose someone made the "overheating-engine" happen on purpose?

Why would someone bend the impeller blades in like that? They do appear to be intact, just bent inwardly, is this false? Are they really worn that much?

They rusted so much that the steel became so thin, that the pressure of the water flow peeled them inwards, and busted off a couple. Read the discussion- the OP said he could easily bend the vanes back and forth and break them off with his fingers.

John Davies
Spokane WA USA

 

[Saint J VT]

Ahhh,

I see, I completely understand, now!
The metal fins thinned to the point of catastrophic-failure!

I know cavitation can occur in certain fluids under certain velocities, and, under certain circumstances. Cavitation will typically result in the eating away of components which are immersed within the agitated (boiling-type) water. I wonder how much antifreeze prevents cavitation and how much of this could be related to cavitation.

I know in hydronic boiler systems, the system is a closed system, and after a while a lot of the oxygen is removed from the water, thus making it like black sludge, which still works fine within the boiler vessel and within hydronic heating baseboards, radiators, etc. I suppose, though, the fact that the car typically has an open-design, being open to the radiator canister could account for oxygen constantly being dispersed within the water for the entire cooling system whereas a boiler has an Extrol tank which is a diaphragm tank which takes up the necessary space of the expanding water as it is heated and pushes that water back into the closed system as the water contracts, taking up less space as it cools.

 

[FOX-]

Frozen coolant would probably trash a water pump pretty good as well. The only pump I had fail was on my Ford. The bearing was failing and metal shaving were all over the engine compartment. It made a horrible noise as well. I just turned on the heat full blast and drove it home. I wonder if this pump was making any noise from the fins coming in contact with the housing? The pump on my H6 was just starting to weep when I replaced the timing chain.


-Tim

 

[Saint J VT]

Frozen coolant would probably trash a water pump pretty good as well.....

Yes, as well as blowing out the freeze plugs and possibly cracking the block!

 

[FOX-]

Yes, as well as blowing out the freeze plugs and possibly cracking the block!

Bursting hoses, breaking the thermostat, destroying the radiator which would probably be the first to go.

Yeah, I think there are loads of reason to run a proper mixture of distilled water and ethylene glycol.

-Tim

 

[lashlee]

Don't forget that cavitation causes the rapid collapse of the bubbles created and that slam of water against the impeller is what causes the degredation of the material. Like someone else noted that the anti-freeze may help but the minerals in regular tap water doesn't help!

 

[RobLog]

I read once that running with distilled water and an additive provides better cooling than any coolant.

Might work for short term intense use, as in a race car ... but distilled water (without coolant) is actually very corrosive in an engine, especially one made of aluminum.

 

[KarlGustav]

Heh. Funny to see my reddit post reposted here. I posted this pic a couple of months ago on this board, and I thought it would be interesting to the folks on that subreddit. I still have that water pump just because it was so crazy. It's part of my gallery of absurd failures, along with my '97 Outback clutch fork that shattered at the pivot point.