Brown tar like deposits and debris in coolant cap
06-08-2016, 03:16 PM
#16
Race Director
I'm thinking (ok hoping) that the condition of the coolant, impeller and hoses will be telling. Interesting in my post last week, 'metal or plastic', a member, (don't recall off top of my head) suggested metal impeller does not deteriorate in coolant over time while plastic one does. I went w plastic. Maybe he was onto something.
Water pump in my Boxster lasted 172K miles. Impeller blades were fine. The bearing was noisy.
Water pump in my Turbo lasted around 120K miles. Impeller blades were fine. Seal was leaking.
The concern with the impeller blades is if the water pump bearings develop excess play and it doesn't take much the impeller can get pulled out of position and the blades contact the engine block. The blades run pretty close to the block walls so the pump is more efficient so it doesn't take much movement of the impeller to cause trouble.
This is why if you hear a noise and it is suspected of coming from the water pump confirm this and promptly deal with it if from the water pump or anything else, even an idler/tensioner roller bearing.
One doesn't want to risk everything to nurse a water pump on his Porsche engine.
06-08-2016, 09:30 PM
#17
Not on *to* something. On something...
Water pump in my Boxster lasted 172K miles. Impeller blades were fine. The bearing was noisy.
Water pump in my Turbo lasted around 120K miles. Impeller blades were fine. Seal was leaking.
The concern with the impeller blades is if the water pump bearings develop excess play and it doesn't take much the impeller can get pulled out of position and the blades contact the engine block. The blades run pretty close to the block walls so the pump is more efficient so it doesn't take much movement of the impeller to cause trouble.
This is why if you hear a noise and it is suspected of coming from the water pump confirm this and promptly deal with it if from the water pump or anything else, even an idler/tensioner roller bearing.
One doesn't want to risk everything to nurse a water pump on his Porsche engine.
Water pump in my Boxster lasted 172K miles. Impeller blades were fine. The bearing was noisy.
Water pump in my Turbo lasted around 120K miles. Impeller blades were fine. Seal was leaking.
The concern with the impeller blades is if the water pump bearings develop excess play and it doesn't take much the impeller can get pulled out of position and the blades contact the engine block. The blades run pretty close to the block walls so the pump is more efficient so it doesn't take much movement of the impeller to cause trouble.
This is why if you hear a noise and it is suspected of coming from the water pump confirm this and promptly deal with it if from the water pump or anything else, even an idler/tensioner roller bearing.
One doesn't want to risk everything to nurse a water pump on his Porsche engine.
06-08-2016, 09:54 PM
#18
Three Wheelin'
Check the coolant hoses for non-OEM....haven said that, I can only barely make out what seems like the classic 996/997 PN sequence on the hoses I've looked at in my 06. Theory is that if an aftermarket Auto Zone hose was used it may not be compatible with the OEM coolant.
Second theory....PO had a small leak somewhere in the cooling system and put some stop leak in the coolant. The ones I've seen are dark brownish in color.
I did say speculation.....
06-09-2016, 02:21 AM
#19
Ok...speculation time!
Check the coolant hoses for non-OEM....haven said that, I can only barely make out what seems like the classic 996/997 PN sequence on the hoses I've looked at in my 06. Theory is that if an aftermarket Auto Zone hose was used it may not be compatible with the OEM coolant.
Second theory....PO had a small leak somewhere in the cooling system and put some stop leak in the coolant. The ones I've seen are dark brownish in color.
I did say speculation.....
Check the coolant hoses for non-OEM....haven said that, I can only barely make out what seems like the classic 996/997 PN sequence on the hoses I've looked at in my 06. Theory is that if an aftermarket Auto Zone hose was used it may not be compatible with the OEM coolant.
Second theory....PO had a small leak somewhere in the cooling system and put some stop leak in the coolant. The ones I've seen are dark brownish in color.
I did say speculation.....
There is no PO, my baby for 10+ years now. Been no work done on the motor other than maintainance.
If there is an answer I should know tomorrow. Thanks.
Later
06-09-2016, 10:58 AM
#20
Not on *to* something. On something...
Water pump in my Boxster lasted 172K miles. Impeller blades were fine. The bearing was noisy.
Water pump in my Turbo lasted around 120K miles. Impeller blades were fine. Seal was leaking.
The concern with the impeller blades is if the water pump bearings develop excess play and it doesn't take much the impeller can get pulled out of position and the blades contact the engine block. The blades run pretty close to the block walls so the pump is more efficient so it doesn't take much movement of the impeller to cause trouble.
This is why if you hear a noise and it is suspected of coming from the water pump confirm this and promptly deal with it if from the water pump or anything else, even an idler/tensioner roller bearing.
One doesn't want to risk everything to nurse a water pump on his Porsche engine.
Water pump in my Boxster lasted 172K miles. Impeller blades were fine. The bearing was noisy.
Water pump in my Turbo lasted around 120K miles. Impeller blades were fine. Seal was leaking.
The concern with the impeller blades is if the water pump bearings develop excess play and it doesn't take much the impeller can get pulled out of position and the blades contact the engine block. The blades run pretty close to the block walls so the pump is more efficient so it doesn't take much movement of the impeller to cause trouble.
This is why if you hear a noise and it is suspected of coming from the water pump confirm this and promptly deal with it if from the water pump or anything else, even an idler/tensioner roller bearing.
One doesn't want to risk everything to nurse a water pump on his Porsche engine.
If the bearing goes bad, you'll hear it or see the leak. Or if the coolant gets into the bearing and washes out the lubricant, the bearing locks up which render the vehicle un-drivable. Unless you continue to drive with a noisy or leaky water pump, there's little chance the play is enough to cause rubbing.
Either way, this kind of debate is similar to which oil is better. It prob won't change anyone opinion so it's pointless.
More pictures
06-09-2016, 11:41 AM
#22
Fact 1: replace water pump because of leak and wobble – plastic impellers are fine.
Fact 2: There are few pictures of broken plastic blade on this site.
Many people see those facts and think: (1) plastic impellers are fine, bearing goes bad way before AND (2) broken blades are rare, nothing to worry about.
I look at the facts and think: (1) No blade/housing contact occurs even with bad bearing (there’s no chance plastic blades can survive a contact with metal housing). (2) In few cases, blades can break for no real reason. I picked metal blade to fix (2) and depend leak/noise symptom to know when to replace the pump.
Just a different ways to draw conclusions out of the same thing.
Last edited by nk215; 06-09-2016 at 01:14 PM.
06-09-2016, 01:15 PM
#23
This is what I saw during my research also. It’s interesting that people look at the same fact and draw different conclusions:
Fact 1: replace water pump because of leak and wobble – plastic impellers are fine.
Fact 2: There are few pictures of broken plastic blade on this sites.
Many people see those facts and think: (1) plastic impellers are fine, bearing goes bad way before AND (2) broken blades are rare, nothing to worry about.
I look at the facts and think: (1) No blade/housing contact occurs even with bad bearing (there’s no chance a plastic blades can survive a contact with metal housing). (2) In few cases, blades can break for no real reason. I picked metal blade to fix (2) and depend leak/noise symptom to know when to replace the pump.
Just a different ways to draw conclusions out of the same thing.
Fact 1: replace water pump because of leak and wobble – plastic impellers are fine.
Fact 2: There are few pictures of broken plastic blade on this sites.
Many people see those facts and think: (1) plastic impellers are fine, bearing goes bad way before AND (2) broken blades are rare, nothing to worry about.
I look at the facts and think: (1) No blade/housing contact occurs even with bad bearing (there’s no chance a plastic blades can survive a contact with metal housing). (2) In few cases, blades can break for no real reason. I picked metal blade to fix (2) and depend leak/noise symptom to know when to replace the pump.
Just a different ways to draw conclusions out of the same thing.
I responded to this question last time w 'do a search but you will not find an answer' Didn't mean it it in a harsh or negative way but there is no good or right answer.
The theory of metal impellers gouging out the engine block seems to come from one of the experts in the field, a major researcher and rebuilder. You know who I mean if you have been following this. Gotta assume he knows of what he speaks and has seen it happen. Other parts providers recommend metal over plastic which intuitively makes sense but goes at odds to the JR advice.
There was one member who swapped out a good pump and had problems with the replacement pump. Ironic comes to mind there.
All I know is that at 6500 rpm in third gear I just don't much care
Good luck with your pumps guys.
06-09-2016, 01:21 PM
#24
Update: tech advises that all fluids drained from motor are clear. He says he often finds smudges on the coolant caps but that unless there is material in the coolant itself it is not to be worried over. I hope to see car back today and will check out the pump to see what shape it is in.
06-10-2016, 12:08 PM
#25
Final analysis:
Inspected water pump, minimal play fr-r in bearing but considerable wobble and angular play. Reportedly enough so that the belt was not running square to the pulleys.
The sludge in the coolant cap that was a concern was the seal in the pump being eaten up by the wobble in the shaft. That it developed so quickly suggests to me the pump was failing rapidly.
The impeller was fine, showed no chipping of surface wear I could see.
Bottom line is that my water pump failed at 10+ years and 43,000 miles. Failure mode was bearing wear. There was sufficient warning in the form of coolant leak to avoid a catastrophe. I would advise against drawing any conclusion from this as to what's going on in your motors.
The seal on the bearing may fail rapidly as the shaft wobbles and if you see unwanted tar-like stuff in the coolant cap or on filler neck (in absence of other more serious symptoms) it is because it is being worn away and the coolant system vents thru the cap as I understand it.
Anyway the old girl is back and to say I am relieved would be an understatement. Thank you all once again for your input.
Gerry
Inspected water pump, minimal play fr-r in bearing but considerable wobble and angular play. Reportedly enough so that the belt was not running square to the pulleys.
The sludge in the coolant cap that was a concern was the seal in the pump being eaten up by the wobble in the shaft. That it developed so quickly suggests to me the pump was failing rapidly.
The impeller was fine, showed no chipping of surface wear I could see.
Bottom line is that my water pump failed at 10+ years and 43,000 miles. Failure mode was bearing wear. There was sufficient warning in the form of coolant leak to avoid a catastrophe. I would advise against drawing any conclusion from this as to what's going on in your motors.
The seal on the bearing may fail rapidly as the shaft wobbles and if you see unwanted tar-like stuff in the coolant cap or on filler neck (in absence of other more serious symptoms) it is because it is being worn away and the coolant system vents thru the cap as I understand it.
Anyway the old girl is back and to say I am relieved would be an understatement. Thank you all once again for your input.
Gerry