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I note that on Ed's website the coupler is described as a consumable item so the obvious question here is whether it has been consumed as intended - i.e. some event put unacceptable levels of resistance into the system and it sheared- or- the insert has "degraded" over time to the point it could no longer hold the drive resistance of the pump and thus failed that way [or a combination of both].
I suppose the next logical question may be if they are consumable at what point in its service life are they considered to have been consumed to the point of needing pre-emptive replacement to avoid tow truck recovery scenarios? Your pump has been in service 7 years and has covered 35k km- the timeline is reasonable the mileage arguably less so. Given hoses last 5 or 6 years before pre-emptive replacement is appropriate maybe such a time interval may be prudent/reasonable for Ed's pump to optimise its long term performance.
As with any engineered item, design/testing is one thing but there is no substitute for real world practical experience and if time exposure is a factor then this will start to show. I am not quite sure of the timeline but I suspect you may well have been one of the first uptakers for this item.
Bottom line is that it seems to me that the pump has done its intended job and deserves refurbishment with a new consumable which presumably will be peanuts compared to a new pump. At the very least you might reasonably expect another 7 years of service assuming everything else is up to snuff.
It will also be interesting to see whether the impeller shows any signs of distress/mechanical contact to have induced this condition. The interesting thing to be evaluated in this case is whether this is a success or a failure- at the moment I am viewing this as a successful failure. For sure if the impeller has full integrity I would not hesitate to reuse this pump and continue to add to operational experience for this very interesting piece of kit.
I have experienced two pump failures- both with impeller migration and no bearing damage- one was the stock pump the other a rebuilt pump. Both lasted about 7 years - the first one covering some 80k km and rebuilt one about 60k km but I could do nothing with either of them after failure.
If you ultimately decide to reuse this pump do check with Ed about whether there is a need to replace the shaft dynamic seal whilst it is apart.
Fred, my thoughts parallel yours - replace the coupler and go - but I was confused by Bertrand's comment:
"One thing I did see is that the pulley is turning. So not seized."
My understanding of Ed's Engine Guardian was that the pulley was intended to continue turning if the pump stopped, in order to protect the timing belt.
Fred, my thoughts parallel yours - replace the coupler and go - but I was confused by Bertrand's comment:
"One thing I did see is that the pulley is turning. So not seized."
My understanding of Ed's Engine Guardian was that the pulley was intended to continue turning if the pump stopped, in order to protect the timing belt.
Steve,
I believe Bertrand was trying to convey your understanding and that is spot on.
Bertrand please make sure to order the parts I suggested,
increases the odds of no failures
The thermostat (tested good yesterday), rear seals, O ring, tank cap, tank, heater valve and all coolant hoses under the hood were changed last year.
Everything should be good I think. Did maybe 6k km since.
I'll make sure with the pressure tester that all hoses clips are tight enough this time!
I note that on Ed's website the coupler is described as a consumable item so the obvious question here is whether it has been consumed as intended - i.e. some event put unacceptable levels of resistance into the system and it sheared- or- the insert has "degraded" over time to the point it could no longer hold the drive resistance of the pump and thus failed that way [or a combination of both].
I suppose the next logical question may be if they are consumable at what point in its service life are they considered to have been consumed to the point of needing pre-emptive replacement to avoid tow truck recovery scenarios? Your pump has been in service 7 years and has covered 35k km- the timeline is reasonable the mileage arguably less so. Given hoses last 5 or 6 years before pre-emptive replacement is appropriate maybe such a time interval may be prudent/reasonable for Ed's pump to optimise its long term performance.
As with any engineered item, design/testing is one thing but there is no substitute for real world practical experience and if time exposure is a factor then this will start to show. I am not quite sure of the timeline but I suspect you may well have been one of the first uptakers for this item.
Bottom line is that it seems to me that the pump has done its intended job and deserves refurbishment with a new consumable which presumably will be peanuts compared to a new pump. At the very least you might reasonably expect another 7 years of service assuming everything else is up to snuff.
It will also be interesting to see whether the impeller shows any signs of distress/mechanical contact to have induced this condition. The interesting thing to be evaluated in this case is whether this is a success or a failure- at the moment I am viewing this as a successful failure. For sure if the impeller has full integrity I would not hesitate to reuse this pump and continue to add to operational experience for this very interesting piece of kit.
I have experienced two pump failures- both with impeller migration and no bearing damage- one was the stock pump the other a rebuilt pump. Both lasted about 7 years - the first one covering some 80k km and rebuilt one about 60k km but I could do nothing with either of them after failure.
If you ultimately decide to reuse this pump do check with Ed about whether there is a need to replace the shaft dynamic seal whilst it is apart.
Rgds
Fred
I agree with you Fred that the rubber coupler is a consumable part of the pump. The question is when it should be changed. When I removed the pump in 2014 (for a belt change), per Ed recommandation I checked if there was any play in the impeller bearing. There was any. He kindly offered me to send me a new coupler and a new pulley cover (new design). BTW, the pump had maybe about 20k km on it at that time. I put maybe 15k km on the new coupler since.
Of course I will know for sure that everything (beside the coupler) is fine or not when I'll remove the pump.
I find that this is a great design since the beginning.
But if the impeller bearing and pulley are fine, I wonder, though, why the coupler did let go after only 3 years and 15k km.
For now, I have a new Laso pump in hand (thanks Luc) and will put this one on.
I'm running a Guardian pump, and since I'm also running a PKT with no tension warning light, it gives me a lot of peace of mind. But I do hope you get to the bottom of this. Regarding that coupler, how much disassembly is required to put a new one in? I assumed the pump would have to be removed, but from a few comments, it seems maybe that's not true?
To remove the coupler, you don't need to remove the pump.
You need to get to the pump, remove the coupler cover (four screws) and you have access to it.
Thanks...went back and looked at your picture of it from before, makes sense now.
Originally Posted by Bertrand Daoust
Jeff,
To remove the coupler, you don't need to remove the pump.
You need to get to the pump, remove the coupler cover (four screws) and you have access to it.
Bertrand - Great to hear there is no blown head gasket! Excellent posts on your process of elimination. And congratulations on becoming a famous data point! I am with others who see this as not so much a failure of this innovative pump...rather an indicator of necessary investigation and possible coupler revisions. On the other hand I'm sure my thoughts and feelings would be the same as yours after dodging this big bullet.
All threads on Rennlist might help others in the future.
Maybe this one will also. Never know...
More than ever, I know that without this community, you included, I would not drive a 928.
The help I got this week is priceless.
Of course I put a bit of $$ on my dream car, but without you all, it would not have been possible to own my car for that long and enjoy it year after year.
Thanks to all of you.
Spent some time today removing the pump and a bit of cleaning.
Ready to install the new one in the next few days.
06-23-2017, 04:27 AM
