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Steve Tinker · 06-30-2011, 03:26 PM

Hi Doug - looks like your preventative maintenance is keeping you busy.
As to the damaged impeller, does the damage look like an actual breakage or erosion of the plastic - difficult to see from here. How many miles /years has the pump done? I bet you were losing 25% of your coolant flow looking at the impeller vanes......

If its erosion, there shouldn't be a problem, but if bits have actually snapped off, then the debris could still be in the system. The first place I would look ('cos its easy) is in the thermostat housing to see if the thermostat has stopped the damaged bits from circulating. I think Jeff (JFP in PA) has suggested in the past to "back flush" the system to make sure any loose bits are flushed out before bolting back together - how difficult this is I'm not sure but its probably easier and cheaper than having a coolant blockage in the cylinder heads.

I'm sure one of the professionals with more experience than me will chime in with some good advice...

06-30-2011, 03:26 PM	#2
Steve Tinker Registered User Join Date: Dec 2008 Location: Queensland, Australia Posts: 1,522	Hi Doug - looks like your preventative maintenance is keeping you busy. As to the damaged impeller, does the damage look like an actual breakage or erosion of the plastic - difficult to see from here. How many miles /years has the pump done? I bet you were losing 25% of your coolant flow looking at the impeller vanes...... If its erosion, there shouldn't be a problem, but if bits have actually snapped off, then the debris could still be in the system. The first place I would look ('cos its easy) is in the thermostat housing to see if the thermostat has stopped the damaged bits from circulating. I think Jeff (JFP in PA) has suggested in the past to "back flush" the system to make sure any loose bits are flushed out before bolting back together - how difficult this is I'm not sure but its probably easier and cheaper than having a coolant blockage in the cylinder heads. I'm sure one of the professionals with more experience than me will chime in with some good advice... __________________ 2001 Boxster S (triple black). Sleeping easier with LN Engineering/Flat 6 IMS upgrade, low temp thermostat & underspeed pulley. 2001 MV Agusta F4. Last edited by Steve Tinker; 06-30-2011 at 03:28 PM.