Water Pump Longevity

[pilut2]

I just replaced my water pump on my 1999, it was the original and seemed to be as good as new. Can someone explain to me, why it is recommended to change out the pump every 4-5 years? Are they of poor quality or unusually stressed compared to other vehicles?

Prior to my Boxster I have only had to do one water pump in 35 + years if vehicle ownership and multiple cars of various brands.

[Rob175]

Personally, I would NEVER "proactively" remove a working water pump, for fear that it "might fail". My 20 year old original water pump began leaking two months ago. It was just a slow leak as indicated by a few drops of coolant on the garage floor, it was not a catastrophic failure. Got a few quotes and had it replaced....easy peasy.

[paulofto]

I too wonder about replacing functioning water pumps and premature failure.

I have owned dozens of vehicles over the past 45 years and I can state I have never had to replace a water pump either due to failure or proactively. Maybe i have been lucky but so far my Boxster shows no signs of needing one either (~65K miles). Any vehicles I have owned I tend to keep forever but I do maintain them very well.

[pilut2]

Originally Posted by Rob175

Personally, I would NEVER "proactively" remove a working water pump, for fear that it "might fail".

Normally I would agree, but there seem to be plenty of no warning, catastrophic failures of these pumps. The vanes seem to erode as well. This was not my experience, as my vanes look like new. I am the second owner of the car and it was exclusively dealer serviced by the original owner. According to the service records the original coolant was still in the car. I drained pristine looking green coolant out. Internals visible from waterpump and thermostat galleries show absolutely no corrosion.

[kk2002s]

So in general I have never been a replace working parts as maintenance
BUT
That was before I bought a Porsche.
While I have replaced only a couple parts that failed (Expansion tank, Climate control display, evap canister, purge valves) the rest , WP, Thermo, Motor mount, AOS, Oil cooler 'O' rings I have done because it made sense.
The org. Motor mount was bad so that was a good replace
The org. AOS was fine but 16 years old. I had bought a new as a spare and carried with me on long road trips so after a year or so I just put it in.
The org WP, Thermo, 'O' rings - I wanted to do a coolant Flush and replace so it made sense to do those components. The org. WP was in good shape

I feel with these cars and certain parts that waiting until they fail usually means a tow job, not a limp it home to fix.

[rick3000]

The idea behind the preventative WP replacement is that if it fails, which is more likely the older the pump is, the plastic impeller will break, and the shards can lodge in the radiators reducing their cooling efficiency. That ends up being a bigger problem than $200 for a new pierburg WP every few years. I had mine replaced once under warranty and changed it myself at 90k when I flushed the coolant and installed a third radiator.

[RedTele58]

Unlike most here, I'm a big proponent of replacing most failure items before they break.

Growing up, my Dad had a general aviation, sport aviation and racing aircraft engine shop. Parts were replaced and engines rebuilt on hours accumulated, not on failure. Too many opportunities to die waiting to replace a part until it breaks.

My entire career has been as a military aviator. Again, in military aviation, maintenance/replacement is done mostly on hours accumulated. Things break enough under a conservative system as this without running components to failure.

Do you sometimes feel a pinch in your wallet when you replace something that "appears" to still be good? Yup. Does it suck twice as hard to be sitting on the side of the road with a dead car, or having something break that causes engine failure? Double yup.

Water pumps, AOS, and things that have to come out and go back in while you're replacing something else all make sense to me to put on a regular replacement schedule.

Just my 2 cents worth and unasked for opinion...

[Frodo]

Originally Posted by rick3000

The idea behind the preventative WP replacement is that if it fails, which is more likely the older the pump is, the plastic impeller will break, and the shards can lodge in the radiators reducing their cooling efficiency.

...yup, and, more importantly, my understanding is that those little pieces can lodge in the head, blocking coolant flow and creating local hot spots and heat-related cracks in the cylinder head.

So it's not just a coolant issue, it's an engine integrity threat.

I had my WP go many thousands of miles ago. From the time I saw an occasional drop of coolant leak with an accompanying slight hot coolant smell until the thing (WP) went totally and suddenly and utterly south was not long. Not a lot of lead time to react. Bit the bullet, got her up on jack stands, and changed out the WP and thermostat (and the motor mount while I was there). Before refilling with new coolant, I flushed the hell out of the system and never retrieved a single shard of WP impeller. Fortunately I've had no problems. But apparently those problems do sometimes happen.

Do a search. There's a lot of info on the topic here. Jake Raby, who knows these engines better than maybe anyone and who, unfortunately, no longer provides input to this forum, has in the past talked a lot about this issue.

[thstone]

I race my Boxster and once asked about replacing my entire engine as preventative maintenance.

I didn't do anything. 11 track hours later, the engine failed.

I don't think that there is a right or wrong answer to preventative replacement - it really depends on how you feel about unexpected costs and/or downtime when something does eventually fail.


http://986forum.com/forums/552195-post1.html

Well, that didn't go as planned

[Subman]

Bought a 2002 Boxster S with 115,000 miles this summer. It was obvious that the PO had replaced the water pump recently, but there was no way to know if he did it proactively or after failure.

Among other issues, the car had some small oil leaks from the oil cooler that sits above the engine. It's a small heat exchanger with engine oil on one side and coolant on the other. When the cooler was removed to replace the O-rings, inside the coolant section were half a dozen chunks of water pump impeller. Clearly, the pump had at some point suffered a failure - only then was it replaced.

Morals of the story - yes, they can and do fail - and if they do, look inside the oil cooler for impeller parts.

[78F350]

I've been avoiding this thread due to all the happy and optimistic posts that it started out with. I don't care to argue online with people who are already satisfied and secure in their knowledge.

I totally agree with Rick and the others who said to replace it as preventative maintenance. Like an IMS failure, a catastrophic water pump failure is statistically unlikely to happen to your car. Like an IMS failure, a catastrophic water pump failure can ruin your engine. It is a lot easier and less expensive to replace a water pump regularly than it is to replace an IMS. Why not do it?

My experience with it is a little more extreme than most cases, but you can read about plenty of problems on Rennlist and other sites if you look around. I bought a cheap Boxster that had lots of issues and had probably been using dirty pond water for coolant. The water pump looked like this when I replaced it:



The engine did not overheat, but it seemed to have a hot-spot in the cooling passages that would build pressure and cause coolant to vent out the over-pressure valve in the tank. I tried various means of flushing the engine, short of disassembly and replaced the oil cooler. It didn't work. In the end, I decided to push the engine to failure rather than put more time and money into it. It has now reached that state and I'm pretty sure it has a cracked head.

[BYprodriver]

Originally Posted by RedTele58

Unlike most here, I'm a big proponent of replacing most failure items before they break.

Growing up, my Dad had a general aviation, sport aviation and racing aircraft engine shop. Parts were replaced and engines rebuilt on hours accumulated, not on failure. Too many opportunities to die waiting to replace a part until it breaks.

My entire career has been as a military aviator. Again, in military aviation, maintenance/replacement is done mostly on hours accumulated. Things break enough under a conservative system as this without running components to failure.

Do you sometimes feel a pinch in your wallet when you replace something that "appears" to still be good? Yup. Does it suck twice as hard to be sitting on the side of the road with a dead car, or having something break that causes engine failure? Double yup.

Water pumps, AOS, and things that have to come out and go back in while you're replacing something else all make sense to me to put on a regular replacement schedule.

Just my 2 cents worth and unasked for opinion...

When I got out of the USMC I got a job at the local FBO where my Father kept his plane & I joined the air national guard to work on their flight line.

[pilut2]

Originally Posted by 78F350

The water pump looked like this when I replaced it:

Yikes!! I can't imagine what the rest of the innards looked like. This is my 20 year old pump.

[piper6909]

Originally Posted by 78F350

I've been avoiding this thread due to all the happy and optimistic posts that it started out with. I don't care to argue online with people who are already satisfied and secure in their knowledge.

I totally agree with Rick and the others who said to replace it as preventative maintenance. Like an IMS failure, a catastrophic water pump failure is statistically unlikely to happen to your car. Like an IMS failure, a catastrophic water pump failure can ruin your engine. It is a lot easier and less expensive to replace a water pump regularly than it is to replace an IMS. Why not do it?

My experience with it is a little more extreme than most cases, but you can read about plenty of problems on Rennlist and other sites if you look around. I bought a cheap Boxster that had lots of issues and had probably been using dirty pond water for coolant. The water pump looked like this when I replaced it:



The engine did not overheat, but it seemed to have a hot-spot in the cooling passages that would build pressure and cause coolant to vent out the over-pressure valve in the tank. I tried various means of flushing the engine, short of disassembly and replaced the oil cooler. It didn't work. In the end, I decided to push the engine to failure rather than put more time and money into it. It has now reached that state and I'm pretty sure it has a cracked head.

WOW! How many were miles on it? My 2002 original pump with 92K miles looked perfect (aside from very slight play, that's why I changed it.)

[pilut2]

Originally Posted by piper6909

WOW! How many were miles on it?

I'm not sure if your "Wow" comment was related to the good pump or 78F350's knarly one- my beautiful looking pump was 20 years old but the car only has 42,000 miles on it- this was the original pump and likely the original coolant too. I'm glad that I switched it out- but I think that it had a bit of life left in it, maybe another 20 years (lol).

[78F350]

Originally Posted by piper6909

WOW! How many were miles on it? My 2002 original pump with 92K miles looked perfect (aside from very slight play, that's why I changed it.)...]

I don't know how many miles were on it, that engine had been swapped into the car at some point. Most of the eight to ten water pumps I have removed looked as good as yours. One had some slight scrapes on the blades from bearing play, one had clumps of congealed coolant from improper coolant mix. I think they all had the original gasket, so first time changed. Call that a catastrophic failure rate of 10% if left 'till there's a sign of trouble (in my experience). All four IMS bearings I've removed (with over 100k miles on them) have looked great too.

[78F350]

Originally Posted by pilut2

Yikes!! I can't imagine what the rest of the innards looked like. This is my 20 year old pump.

The tolerance between the impeller blades and block is very tight on these engines. Just a little bearing play and they begin to contact and wear against the block. That's why the professionals keep saying not to use pumps with metal impellers, they will grind away the block instead of the blades.
Looks like yours was starting to have contact. Good call on replacing it. (Picture rotated and enlarged.)

[pilut2]

Originally Posted by 78F350

Looks like yours was starting to have contact. Good call on replacing it. (Picture rotated and enlarged.)

You might be right. There doesn't seem to be any play in the bearing - but I have noticed that the engine seems to be a bit quieter, there may have been a bit of scraping going on. She is now put to bed for the winter - tucked away in my hangar.

[pilot4fn]

Today I swapped the waterpump and same time the low temp thermostat.
Suprising was that in most instructions I found it is recommended to open/close some of the waterpump bolts from below and some from inside - including that some recommend to remove the passenger seat.
I did remove and install the waterpump and thermostat from under the car and it was actually suprisingly 'roomy' to also torque the bolts.
BTW: the old water pum had approximately 115.000km adn I changed it as a precautionary, partly because the previous owner had changed the pump in past and I do not know what pump it was (not swapped at Porsche dealer, but pivate dedicated shop)

[Rob175]

As I wrote previously in this thread my Boxster's water pump (1998) was just replaced 2 months ago BUT NOT because it failed, or the vanes were self distructing.....instead the pump just began leaking., no more, no less. The pump was original and the vanes looked perfect when removed.