Frino

The latest Excellence has a good article summarizing the various failure modes of the M96 water pumps, including potential engine/crankcase endo scenarios.

The writers wrap up the article by recommending that 996/997 water pumps be replaced every 4 years or 50K miles, whichever is sooner. They also recommend that the coolant system be flushed every two years.

My view to date on the water pump issue is to look for the various telltales (leaks noises, etc.) before replacement. Hadn't even thought about flushing the coolant given Porsche's lifetime service interval.

I would welcome the feedback of our esteemed SME's on these recommendations.

utkinpol

In my case I noticed coolant residue on the pump body, sent a picture to service manager and he approved replacament covered by cpo no questions asked.

JW911

Yes I read that article and it got me thinking too. I am at 60K miles and I am considering a replacement. A coolant flush at this point is also probably not a bad idea, even though my coolant looks visually to be in great shape. I have to say that replacing coolant every 2 years is extreme overkill though. Modern coolant in this modern engine have a very long service life. No doubt about it. But I am 7 years and I intend to keep the car for quite a while. So I will probably do it within the next 6 months.

USMC_DS1

My C2S is at 4yrs and 52K miles. Flushed my coolant recently(partial 3.5 gal or 8+) when I added the 3rd radiator. I have a new WP in the garage waiting for me to install it over an free weekend. No signs yet of any issues but a good item for preemptive replacement before the plastic fins deteriorate. Suncoast has it on sale for ~$240 with a new gasket(must replace with a new gasket).http://www.suncoastparts.com/product..._Enginecoolant

Good insurance compared to the cost of engine replacement and looks to be a fairly simple DIY job. Will also do the full flush at that point. Although the coolant(water and ethylene glycol) mix might be lifetime coolant. The corrosion inhibitors will deteriorate overtime and it's the inhibitors which prevent rust etc which will eventually lead to leaks and other more serious issues. IMHO Lifetime = until the initial 4 yrs warranty runs out. Much better to flush and replace regularly. In our extreme TX heat I like to replace the coolant every 2-3 yrs on all my vehicles. Here's a decent link re the overall topic of the engine coolant. www.barsleaks.net/faq.html BTW, I'd recommend flushing with new coolant vs. using Bars Leaks. I just found their link somewhat educational for this discussion topic.

Minok

Texas weather is irrelevant. The engine temps are much higher than any ambient temps will ever get, so no matter how hot it gets in Texas, the radiators are dumping heat to the much cooler air.

Rust only happens on steel/iron parts, not sure how much of that is in the engine exposed to the coolant. Oxidation on Aluminum and other metals will also occur, but you do need free oxygen for that to happen. If you don't open the system and let a bunch of oxygen in, I'd think the components of the coolant would tie up the free oxygen well enough to let any slowly entering oxygen be taken care of for some time.

How would the corrosion inhibitors be consumed over time?

Taxi?

I saw that article too. Here's the DIY:

http://p-car.com/996/diy/waterpump/

Macster

I've not read the article yet, but a 40K mile water pump replacement schedule is based on my experience with a number of cars including 2 Porsches is overkill.

However, I do recognize the importance of periodic coolant drains with a refill with new anti-freeze/water (distilled water).

I've used an approx. 4 year schedule for this.

The water pump in my 02 Boxster lasted 170+K miles. Oh, the replacement pump has 84K miles on it. My Turbo's water pump has 92+K miles on it.

Besides the Boxster the last time the only time a water pump in any one of my cars or family cars needed doing was my sister's Camaro back in the early 80's. I did this for her.

Now I have when I rebuilt engines replaced the water pump as SOP but to replace one that is not showing signs of needing replacement is rather expensive preventative repairs.

Oh, the anti-freeze has a real corrosion fight on its hands. I do not understand the chemistry but to view an engine's coolant passages is to view an ugly surface that is a dead looking flat grey from corrosion. I'm talking about alum. engines.

I have disassembled engine pics (996 engine with 20K miles) that shows the coolant passages and the crankcase surfaces and the difference is night and day.

A two year coolant drain/refill is a bit extreme but leaving the stuff in there for a lifetime -- whatever that is (as one WAG put it lifetime could be 4 years, 50K miles for this is the extent of the new car warranty) -- is imho just asking for expensive trouble down the road.

Sincerely,

Macster.

Boatsonthebrain

At 6 years and almost 50K miles, my '06 C2S runs at a 'normal' 200-225 deg. with no signs of any leaks, but still it's going in to the dealer next week for a water pump replacement & coolant flush. Given the relatively low cost of the factory third radiator, will be having that installed at the same time as a 'while you're in there' exercise.

Probably overkill, and I admit the Excellence article may have had something to do with the decision, but having replaced water pumps that started leaking and made a mess of the engine bay on a couple of previous (higher mileage) cars, I vowed this time to try to stay ahead of the game. That, along with some piece of mind, is worth the cost every 6+ years or so - for me.

jason952

cheap insurance, but sad that modern porsche and bmw cars require prophylactic cooling system service. what a joke any "lifetime" fluids are!

In BMW speak, lifetime fill means lifetime of the parts, not the car.....

JO

KNS

+1 to what Jason said. On my BMW I flush the system every two years. The coolant has additives that help to extend the life of the plastic and the rubber hoses.

Lifetime: Once the part fails it has reached the end of it's life.

boolala

Replaced leaking water pump at 70 K miles on the '05.

Edgy01

The water pump on my 2006 997S was replaced at around 9,000 by the dealership. Had been seeping for awhile when they finally broke down and ordered a replacement. Since then, nice and tight. At around 68,000 miles now.

sullivas

Anyone know -Is the DIY on the 996 totally applicable to the 997 (05 C2) or are there some differences to the procedure? Thanks

NIACAL4NIA

Most cars built after 2000 require a timing belt + water pump replacement every 100k miles which means a good water pump should last the life of the timing belt. The Porsche has chains but the water pump is still a water pump. Back in the 80s we were told to replace water pumps on the 2nd timing belt which was around 120k. I had a friend with a Porsche 944 who wanted to do preemptive timing belt and water pump at 30k and ruined his engine because the new water pump failed and snapped the timing belt. As of 8/24/2015 My Porsche 996 has 88000 miles still original imsb, clutch and water pump but I had a leaky coolant expansion tank around 70k. My 2002 car is worth around $20k-$22k so I'm not spending 25% of it's value for 5%-8% failure rate on IMS, water pump, ...etc

Petza914

I have 2 2005 997.1 C2S cats. I changed the pump preemptively on mine at about 45,000 miles. Not but a couple months later my wife's failed at about 60,000 miles. Not a drop in the garage until she came back from dropping the kids at school and an hour later there was a 2' circle of coolant below the rear of the car. I'll be following a 50,000 mile service interval on my water pumps. Also moved both cars to the cooler thermostat option.