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Water pump failed, plastic impeller disintegrated, and the face of the block seems to be scored. All I've read in these forums suggests that if I throw a new pump in it, it's a ticking time bomb. There could be plastic blocking some critical passages, and the block surface may be too badly scored to build proper pressure.
The only alternative appears to be a full rebuild. What do you think? Are my fears overblown? Is it only a small percentage of engines that suffer catastrophic failure after a water pump failure like this, or a very significant number?
You can remove the thermostat and see if you can find any broken pieces there. The rest you can try to (reverse?) flush out. I think a few have done that here with success.
I already had the thermostat out since I was going to replace it at the same time. Nothing there, completely clean.
My wife was driving it at the time. As she pulled up, it was billowing coolant smoke that was blown onto the exhaust. I read the temp gauge right away and it was about 2/3, definitely way below red, so initially I wasn't too worried. Still some coolant in the coolant tank as well, but bottom line, the plastic could have circulated all over.
It went 1 mile too far. This is why preventative pump replacement is worth its weight in gold. This has NOTHING to do with mileage, the WP is in service 24/7-365, as it is immersed in coolant.
You must account for all broken impeller pieces, else you will have a great chance of future silent issues occurring.
These pieces leave the WP and then travel into the bank 2 cylinder jackets and head first, the worst place they can go.
It went 1 mile too far. This is why preventative pump replacement is worth its weight in gold. This has NOTHING to do with mileage, the WP is in service 24/7-365, as it is immersed in coolant.
You must account for all broken impeller pieces, else you will have a great chance of future silent issues occurring.
These pieces leave the WP and then travel into the bank 2 cylinder jackets and head first, the worst place they can go.
Jake.....It would be very helpful if you could point the poster to a DIY project on how to get all the pieces out of the system. ie:- how to back flush, if this is needed, or other methods you would use to get to the missing pieces of plastic impeller. Thanks in advance.
Jake.....It would be very helpful if you could point the poster to a DIY project on how to get all the pieces out of the system. ie:- how to back flush, if this is needed, or other methods you would use to get to the missing pieces of plastic impeller. Thanks in advance.
I can't because a back flush will do little to nothing to help this. The pieces don't all break off at once, and with coolant still flowing the pieces are pushed through the system by the remaining impeller blades.
I have tried back flushing, and even made a device to do this using pressurized shop air and water, but it didn't work. Where the pieces travel inside the system as soon as they leave the water pump is the issue.
In my classes I instruct techs NOT to bill for this service, because if they are unsuccessful and even one impeller blade is left in place, and finds the wrong spot in the head to be jammed, leading to a localized hot spot and a resultant crack, that it will be their fault.
in every instance that I have seen the heads had to come off to retrieve all the pieces. In some cases the pieces made it back through the entire system and traveled through the replacement pump, thus taking out its impeller blades, too. That's a rare one, but when this many blades are missing, it can happen.
No easy answer or action for this case. You might retrieve some blades but I doubt you'll get them all. We typically utilize the ultrasonic cleaner with the head immersed in it for 20 minutes to knock the pieces loose, then shop air will blow them out. Nothing else can get them out once they are deep in the head and jammed there, even with the head off the engine.
Every single piece of my failed water pump was sitting right down in the thermostat housing area. I was able to take the thermostat off, get all the pieces just by reaching in there and rebuild the entire impeller on my garage floor. When I changed out my pump, I did not do a flush, I just refilled and burped the system to get any air out. When I changed the coolant overflow tank a few months later I did the coolant flush, and nothing at all came out except coolant. If you look at those passages in there they arent that big, you should be able to find everything. Your scoring looks like normal machine marks.
Every single piece of my failed water pump was sitting right down in the thermostat housing area. I was able to take the thermostat off, get all the pieces just by reaching in there and rebuild the entire impeller on my garage floor. When I changed out my pump, I did not do a flush, I just refilled and burped the system to get any air out. When I changed the coolant overflow tank a few months later I did the coolant flush, and nothing at all came out except coolant. If you look at those passages in there they arent that big, you should be able to find everything. Your scoring looks like normal machine marks.
You got very lucky, especially considering where the T stat is in the coolant path. I've never been that lucky, not even once.
The two bolt inspection plate on the back side(Trans side) of the engine on bank 2 is a good place for pieces to be found, too.
So why hasn't anyone invented a filter or catch or something that can be retrofitted into the coolant lines to collect all the broken pieces when this happens. I don't think this would be a hard thing to do.
So why hasn't anyone invented a filter or catch or something that can be retrofitted into the coolant lines to collect all the broken pieces when this happens. I don't think this would be a hard thing to do.
I did that at least a decade ago.. The issue with it, is it blocks ALL the coolant flow right out of the pump, and you have no idea that you've had a failure. Why is that bad? Because without a flow of coolant, there's nothing to get the temperature up at the coolant temp sender, which is located OUTSIDE the engine, in the front coolant console.
That means you bake the engine, but you never even know it, because the gauge says the engine is normal temp. Lots of good ideas, end up being bad ideas when the whole cause/ effect is looked at in a big picture.
I did that at least a decade ago.. The issue with it, is it blocks ALL the coolant flow right out of the pump, and you have no idea that you've had a failure. Why is that bad? Because without a flow of coolant, there's nothing to get the temperature up at the coolant temp sender, which is located OUTSIDE the engine, in the front coolant console.
That means you bake the engine, but you never even know it, because the gauge says the engine is normal temp. Lots of good ideas, end up being bad ideas when the whole cause/ effect is looked at in a big picture.
Ah, I see. And this brings another thing into question the OP says the temp was 2/3 the way up but based on this, that would be meaningless since the water is not flowing as well. Got it.
09-22-2015, 10:30 PM
996 water pump failure with pics
