Hi,

I've just had the water pump replaced on my 1999 5.9l D for the second time in 2.5 years.
It was leaking at the the weep hole plus there was very severe cavitation damage to the interior wall. The pump efficiency must have been very severly impaired.

Anyway, what could have caused this cavitation damage...?? I run with premix coolant here in Saudi Arabia.

I admit the D has run hot on occasions. When caught in slow moving traffic I've had to let it run until the engine check light came on before clicking off the A/C...and then fried myself rather than the engine, which then gradually cooled off. However this has only happened a couple of times in the last few years.

Can cavitation happen that quickly...??

I've also just had a Black Magic Extreme cooling fan fitted...and hopefully this and the new pump will finally sort things out. My initial reaction to the Flex a Lite's fan was very positive - a pretty solid piece of engineering...

Chris

 

I would suggest looking into getting either an additive or a coolant that will impair cavitation.

 

Was the pump a rebuild?

 

Looking back at you post you weren't talking about the actual blades on the pump? I'm reading it as the housing that doesn't move? Please clarify this for me.

 

The pump is Mopar as sourced from United Motors (the Dodge, Jeep etc dealer) here in Riyadh...
Yes, I'm talking the interior wall of the pump behind the impeller...virtually the entire surface looks like its been eaten away with acid...
I'll try and photo it for tomorrow...

Chris

 

Dayum right bro...


As for the coolant you use any certain brand? Also have you used a water wetter agent or have had the coolant system flushed at all? (flushing with certain cleaners can cause issues)

 

Yeah man your pump was toast my pump looked the same way when i took it off. that caused a scrapping/ squealing sound under the hood. The bearing for the shaft is gone.
Dude you may want to take a look at getting a lower temp thermostat... 180 or lower if ou out there in that heat. It will help you be able to keep the A/C on longer and stay cool you in that stop in go traffic

 

Discharge or recirculation cavitation is the result of changing pressure at the point of exit, the discharge valve. The valve is not able to let all the liquid through as fast as it should, so the currents' different velocities create miniature changes in the uniform pressure. Even such small variations are enough to create the ideal circumstances for cavitation.

In this case I would say build up of resins or mineral could plug the system causing this. Flush that baby out good. The outer casting is softer then the impeller therefore creating the craters.

The other thing it could be is just **** flowing through the system and a full drain including block drain and flush could help ya out. I think this would be more of the cause of the pitting vers cavitation. Have someone maybe pull a block freeze plug and flush that bastered.

Was this a hi-flow pump?

 

I say it's crap in your system. Cavitation can only occur if the component can move (and it has to be quick). Flush that system good and make sure to flush the flushing agent out very good then replace that water pump.

 

I think he's running a 180 Hi- Flow now, but that new fan will help out I think.
The D has a fail safe built in the PCM that manually overides the AC controls when engine temp is too high so is not to overheat the motor. It's doing it's job.