Water Pump Longevity

[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.

[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.

[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.

[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.