Water pump longevity ????

[WorkInProgressK]

Originally Posted by JFP in PA

Again, I disagree. And I apologize that the shop does not take the time to prepare pretty Power Point presentations for you, but that is not what we are about.

The thermostat functions as a throttling device, restricting the volume of coolant returning from the radiators to the engine. As such, a lower temperature stat actually opens sooner (read at a lower temp) than the factory stat, so operating a vehicle with a 160F stat will actually get heat sooner than with an OEM stat. This is a common observation customers give us after changing over, and as we live in an area that often sees weeks of zero or sub zero temperatures, customers that use their cars as daily drivers would be screaming if there was a heat or warmup time issue. Yet in all the years we have been installing these stats, we have not had one complaint, only comments that is nice to get more heat sooner in the winter because the stat is opening sooner and allowing more warm water to circulate.

Metal impeller pumps do not have to completely fail in order to chew up the engine cases. There is only a few thousandth's of clearance between the impeller and the cases, and when these pumps start to wear and the impeller shaft starts to wobble, and they all do, the machining starts. We have had cars come in with complaints of seeping pumps, only to dump the coolant and find it full of finely ground aluminum, requiring us to flush the system to get all the metal out. And after installing a new pump and fresh coolant, the cars returned with complaints of running hotter than normal, particularly in warmer weather. A couple of these customers got annoyed enough about this issue to take the cars back to a dealer, who pulled the water pump, looked at the damage, and promptly told the owners that they needed a replacement engine as the impeller damage could not be repaired. They also confirmed that this is something they see regularly with metal impeller pumps, and why Porsche does not use them.

As for whether or not people choose believe, or even listen to what I have to say, that is entirely up to them. And quite plainly, I do not care if they do or do not choose to listen to us. Those that know me will tell you that I have never posted the name or location of my business online, or on any of the forums I either moderate on or participate in. We don't need any more business than we already have, we are doing just fine. We simply try to inform interested parties in what we have observed or experienced over some thirty years of building, racing, and repairing Porsches.

I appreciate that you help the community. I won't argue that its the only reason why I keep participating. My field of work require thorough study of every situation and we can't forget the big picture. I am just trying to say that the solution isn't always clear cut. You might solve 1 issue and cause two problems. Just like IMS issues is to Porsche cutting cost on engine head castings .

As a friendly reminder, re-read yourself on the heater core part. Heaters(cabin radiator) and engine are on a closed loop system. No thermostat in between. In the morning, you will feel heat at around 100F on the cluster.

Originally Posted by kk2002s

Before low temp thermo, hwy cruising was right around 194 degrees, summer time.
With low temp, my summer temps run around 176 degrees. In the winter it runs 172 degrees. This is using the Torque app for water temp.
Now in stop and go the temp will move up in the 212-215 and the fans come on same as reg thermo. But cruising 50+ mph the temp definitely runs cooler.
Cooler is better

The result is the same(negligible error considering its two different test moments)... 176Fis 6Fto 170F and 194F is 8F to 186F. that 6-8F is the limitation of flow.

At max heat capacity(radiator at 212F), both thermostats should be open at 100%. ANY difference in flow here would mean one is actually better then the other. Under that situation you could say one thermostat is better then the other. Any other test in meaning less for a daily driver. Tracked Cars are a different story where you can tune the fuel and timing map to take advantage to the lower intake temperatures.

[JayG]

There are a few on this forum that consistently know WTF they are talking about and JFP is one of them

[dghii]

I though mine failed at about 125K...I had a very slight coolant loss. During replacement, I realized that one of the mounting bolts (lower passenger side) was very loose. I went ahead with the replacement (along with thermostat) but my original pump looked fine as far as no play and no impeller wear.

Oh well.

[kk2002s]

Before low temp thermo, hwy cruising was right around 194 degrees, summer time.
With low temp, my summer temps run around 176 degrees. In the winter it runs 172 degrees. This is using the Torque app for water temp.
Now in stop and go the temp will move up in the 212-215 and the fans come on same as reg thermo. But cruising 50+ mph the temp definitely runs cooler.
Cooler is better

[JayG]

Originally Posted by JFP in PA

Again, I disagree. And I apologize that the shop does not take the time to prepare pretty Power Point presentations, but that is not what we are about.


As for whether or not people choose believe, or even listen to what I have to say, that is entirely up to them. Those that know me will tell you that I have never posted the name or location of my business online, or on any of the forums I either moderate on or participate in. We don't need any more business than we already have. We simply try to inform interested parties in what we have observed or experienced over some thirty years of building, racing, and repairing Porsches.

+986, 996, 987, 997, 981, 991, 911, etc

You don't want to take his advise, don't.
No skin off his nose or anyone else

[sharkbyte]

Probably in a thread but I haven't seen it and seems appropriate here. When replacing the water pump, are you replacing the hoses and flushing all coolant? I'm planning to replace pump and tstat in the next couple of months. See a lot of discussion about that but very little about hoses and actually flushing coolant.

Thanks - Bryan

[Gelbster]

FWIW, I did not observe any signs of needing to replace any hoses or clamps. Neither did I replace the coolant because it was recent.
But do carefully account for all the impeller blades
What is of great value is to remove debris from between the radiators and condensers.

[10/10ths]

....Every four years.

Mileage is NOT the killer. It's the coolant chemically breaking down the impeller plastic over TIME.

I don't understand why this is such a big deal for people to understand.

Just install the lower temp thermostat and slap in a new OEM water pump every four years.

No. Big. Deal.

It's not a Corolla.

EVERY high performance car has "issues" like these. It's the cost of enjoying a bad ass car. Go talk to the BMW "M" crowd or the MB AMG crowd, or talk to the guys whose Corvettes have grenaded on them.

Just budget a new water pump and AOS every four years.

Simple.

[JayG]

Originally Posted by Gelbster

FWIW, I did not observe any signs of needing to replace any hoses or clamps. Neither did I replace the coolant because it was recent.
But do carefully account for all the impeller blades
What is of great value is to remove debris from between the radiators and condensers.

you pretty much have to drain out the coolant when changing the WP

are you reusing the drained out coolant?
IMHO that is a penny wise and a pound foolise