Water pump shattered? Need help.
#1
Water pump shattered? Need help.
I've never seen this before. Went to the track two days ago and had no issues (kept an eye on coolant temps with an actual gauge), then yesterday I come home from work and notice coolant all over the ground. Pop the hood, and it was coming from my waterpump. No big deal, ordered a mazmart for next day shipping. Well today I decided to take my old waterpump off. What the hell happened inside?! I hope it's safe to install my new waterpump on here! I don't see anything sticking out or any reason it should be unsafe, but what would cause this? I was running 75% distilled water 25% coolant and a bottle of royal purple ice.
#4
SARX Legend
iTrader: (46)
That looks like corrosion damage to me. I am not sure I would reuse that front cover and I would have gone with an OEM replacement pump, the Mazmart pump is not worth the extra $$$$. Is the pump shaft really wobbly?
#5
There doesn't seem to be any play in the shaft. I guess sitting around 9k for a total of an hour could have caused extra stress. Hmm. My plan is to just do a complete drain and fill incase anything is floating around, and hope the area it bolts to is ok :/
#8
No respecter of malarkey
iTrader: (25)
skip the fancy colored snake oil additive
pitting from corrosion and/or cavitation
but if it was corrosion the heater coil etc. would have likely gone out well before then
likely not just a casting issue since it's on both the pump and front housing
cavitation seems like the only conclusion given it exists on both parts right where impeller is, but it would have to be really severe for that to happen like someone had an overdrive pulley on it or something
a bit baffling ...
pitting from corrosion and/or cavitation
but if it was corrosion the heater coil etc. would have likely gone out well before then
likely not just a casting issue since it's on both the pump and front housing
cavitation seems like the only conclusion given it exists on both parts right where impeller is, but it would have to be really severe for that to happen like someone had an overdrive pulley on it or something
a bit baffling ...
#10
Scrappy
iTrader: (1)
That's a new one! The pitting you're seeing in the housing is the damage that cavitation can cause. It happens when a liquid in a very tiny location is turned into a vapor bubble for a short period of time by extremely low pressure (usually behind the impeller blade). The vapor bubbles then collapse with such an intense force per unit area to shatter metals into tiny bits.
The damage to the front cover shouldn't effect the pump's flow too severely since the innermost portion of that inlet ring is still intact, but I wouldn't re-use it in a rebuild if you ever have to do one of those. This is one of the few situations where the Mazmart pump would be beneficial or even necessary, since it significantly reduces cavitation (at the expense of flow). I don't know why it would be cavitating this much other than staying at really high RPMs for minutes at a time, or something as abstract as the coolant mixture having a lower vapor pressure than normal mixtures.
As long as it doesn't progress any further it shouldn't cause issues, and the Mazmart pump should keep that from happening (this is the only time I'll ever suggest that pump).
The damage to the front cover shouldn't effect the pump's flow too severely since the innermost portion of that inlet ring is still intact, but I wouldn't re-use it in a rebuild if you ever have to do one of those. This is one of the few situations where the Mazmart pump would be beneficial or even necessary, since it significantly reduces cavitation (at the expense of flow). I don't know why it would be cavitating this much other than staying at really high RPMs for minutes at a time, or something as abstract as the coolant mixture having a lower vapor pressure than normal mixtures.
As long as it doesn't progress any further it shouldn't cause issues, and the Mazmart pump should keep that from happening (this is the only time I'll ever suggest that pump).
#13
Well I race my car more often then most. Two days ago I was on the track for an hour and it was 93* out. Sitting at 7-9k that long with those hot days make me wonder if I should have done a MM waterpump sooner. Just glad it went at home and not at the track!
I have access to a lift and will just fill it up at home with the new pump and drain and fill it from the radiator and block the next morning incase there is any metal floating around now.
I have access to a lift and will just fill it up at home with the new pump and drain and fill it from the radiator and block the next morning incase there is any metal floating around now.
#14
Never heard of what you're talking about.
#15
I've never seen cavitation on a car water pump, but on a regular HVAC pump sure. Its usually from too low NPSH (the head pressure required to overcome the inlet fitting of the volute, basically causing the suction to create the vapor in the above diagram. If you haven't restricted your hoses, perhaps one got hot and collapsed on the track but is now back to normal shape. If you want to reduce suction head of the pump trim the impeller down in dia, but I'm not recommending you reduce cooling flow by doing so. I'm not familiar with the MM pump, I'm new to Mazdas.
#17
Scrappy
iTrader: (1)
Could you explain what you're talking about? And decreasing the inlet restriction won't help much because on this type of impelller cavitation occurs in a very localized area at the edges of the trailing side of the impeller, and given enough time it will occur no-matter the inlet/outlet pressure differential.
#18
No respecter of malarkey
iTrader: (25)
I suppose somebody could be dumb enough to put acid or some other kind of chemical in there trying to 'clean' the system
I can't see factory components having that severe of cavitation under any circumstance
We'll likely never know why ...
You don't need special anything. OE or OE replacement is fine.
.
I can't see factory components having that severe of cavitation under any circumstance
We'll likely never know why ...
You don't need special anything. OE or OE replacement is fine.
.
Last edited by TeamRX8; 07-23-2015 at 08:30 PM.
#19
I've never seen cavitation on a car water pump, but on a regular HVAC pump sure. Its usually from too low NPSH (the head pressure required to overcome the inlet fitting of the volute, basically causing the suction to create the vapor in the above diagram. If you haven't restricted your hoses, perhaps one got hot and collapsed on the track but is now back to normal shape. If you want to reduce suction head of the pump trim the impeller down in dia, but I'm not recommending you reduce cooling flow by doing so. I'm not familiar with the MM pump, I'm new to Mazdas.
#20
Did you suffer from similar damage as I?
#21
Nowhere near that bad, no, but then our car gets stripped every few hundred miles
It showed up on the pressure gauges on the pump inlet when we were trying to get to the bottom of a cooling issue though, we had a bit of pitting just starting so it was obvious what was causing the cooling issue then.
It showed up on the pressure gauges on the pump inlet when we were trying to get to the bottom of a cooling issue though, we had a bit of pitting just starting so it was obvious what was causing the cooling issue then.
#22
Nowhere near that bad, no, but then our car gets stripped every few hundred miles
It showed up on the pressure gauges on the pump inlet when we were trying to get to the bottom of a cooling issue though, we had a bit of pitting just starting so it was obvious what was causing the cooling issue then.
It showed up on the pressure gauges on the pump inlet when we were trying to get to the bottom of a cooling issue though, we had a bit of pitting just starting so it was obvious what was causing the cooling issue then.
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