Sounds like a physiological issue. *NM*

While my 14-year-old summer-only 986 S has low miles (38k), I'm wondering if there's any common 'defensive practice' advising preemptive replacement of the water pump due to age? Nothing is leaking, the bearings seem fine - should I bother?

Thanks,
John L
Boston
2001 986 S

It doesn't make sense to me to do that, but I'm no expert. BTW: I also have a 2001 986 S with about the same mileage....we need to drive more!

I replaced my water pump after seeing the story in the August 2012 Excellence on water pump failures. Seemed like cheap insurance. The issue is with the plastic impeller breaking up and bits clogging up channels in the cooling system.

I have a 1999 car with 38K miles too. I just did mine while doing fluid changes etc… I do 95% of all my work myself. Main reasons I did it were the impeller blade issue and the fact that if I was on the road on a weekend trip it would cost a ton more to have a failure in that situation… DIY for pump and stat = $350-$400. Tow and reputable shop to do it would be 2-3X that. If DIY and you amortize the cost over miles and years, it's very cheap insurance assuming your not going to drive current pump up to 75K miles, even if it lasted that long… Fixing broken blade in the system at a later time only more time and money to resolve….
Also, IF you have not done motor mount, it's great time for that too… I bought the Lumfoerder (sp?) bushing and had napa push out old and new in. Having mount out allows you to get to pump bolts easier, esp if you want to torque them to spec… Replaced a month ago and done limited driving but mount feels good.

NOTE: My pump looked perfect. No broken blades yet. My motor mount was showing some sign of cracking…. I change coolant (porsche brand) every five years and mix with distilled water.

IF YOU ARE A DIY GUY, I THINK ITS A NO BRAINER DURING YOUR NEXT SERVICE. IF PAYING SOMEONE, MAYBE STRETCH IT IF YOU WANT...

I didn't worry about it for a second until it started leaking.

Thats fantastic… Blades all good too….

... because I seized the engine at Sebring and had to replace the engine.
What a waste, that water pump was still good, same as the clutch.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

I have several friends who became concerned after reading the excellence article. Now, let's look at my statistically insignificant experience:

1. i know of no one who had a truly premature WP failure. yea, they fail, but so does everything.
2. WP failures are not immediately catastrophic, unlike, say timing chains of IMS-bearings
3. a new WP is no guarantee of an improvement.

Let me expand on #3. Two years ago i was putting a new (used) motor in my track car. The new motor had a 13-year old WP, while the original dead motor had a 1 year old new WP. I spun both, and the 1 year old one was noisy, rough and failing. The old unit was smooth and in good shape. So a replacement may do as much harm as good. I suspect some are good and others imperfect - its a QC thing not an age thing.

Water pumps generally have two failure modes. If you get junk in your water, the blades deteriorate. There is no way to check this save pulling it. The other mode is the more common, the bearing fails. Typically this results in a slow leak that gets progressively worse. So, at first sign of leaking, replace it. I see little benefit to doing it earlier.

What is the case for premature replacement? What awful catastrophe do you hope to avoid?

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

... in that generally WPs don't fail prematurely and that when they fail they're not (immediately) catastrophic in nature.

What generally fails first is the seal on the bearing. The leak is so minute that you cannot readily see it and will only escape (as vapor) when the pressure is at its highest (usually after a hard run, when the engine is off).
The telltale sign is a white (powdery) residue on the thermostat (immediately below the WP).

The biggest reason for impeller deterioration is air in the system. People who tend to open their expansion tanks on a regular basis to check the level let air into the system.
This air becomes trapped in pockets and crannies and eventually moves with the flow, but as the bubbles pass through the pump the cavitation starts to pit the impeller blades.
Eventually little pieces of blade fall off which then unbalance the pump and the bearing fails.

I understand the preemptive replacement if you have a water pump at or around 100,000 miles of service and you will be embarking on a long road trip.
It's insurance that you won't be left stranded, waiting for a tow truck and hoping that there's a dealer nearby that can solve the issue.

Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Hadn't ever done it before about a week ago, and that was just to look for signs of oil mixing in. I suppose Porsche's saying to wait for the warning light is to reduce air contamination. Whatever that level is (did someone here mention the amount lost?) it's apparently OK with the factory, assuming the situation is attended to in short order.

Minus 40 degrees... Is that Fahrenheit or Celsius?



Edited 1 time(s). Last edit at 04/22/2015 12:56PM by Laz. (view changes)

That's one of the problems with the 981 coolant system. With the 987 (and I believe the 986) you could see the coolant level without having to open it up.

I recall posting about that here earlier and Pedro asking if I didn't trust the electronic sensors. That's OK, until the sensor says to check the level. I suppose it's an idea to check it maybe once a year to avoid opening it too often. I just don't like warning message coming up during a trip, miles from a dealer or mechanic if I can avoid that by a pre trip check.

and then your expansion tank cracks, then what do you have?

Quote
Boxsterra
and then your expansion tank cracks, then what do you have?

DUH....a cracked expansion tank

"A mile of highway will take you one mile. A mile of runway will take you anywhere."

Minus 40 degrees... Is that Fahrenheit or Celsius?