another dead boxster @#$%!

[Jake Raby]

Its not mileage that counts!!!!
Its TIME IN SERVICE!!!

The water pump impeller doesn't wear.. All it is moving is clean coolant, there is no friction. What breaks the impeller blades is EXPOSURE to the environment that the impeller is a part of whether the engine is running or not.

Because of this we see cars with 10K miles from 1997 crack heads because the impeller has become brittle and a piece of it snapped off.

The last M96 engine that was built came from 2005, at this point ALL M96 engines are AT LEAST 5 years old and ALL of them need the water pump changed.

Don't consider mileage for an AOS, water pump or IMS precautionary procedure to be carried out. The IMS bearing's outer seal is exposed to engine oil even when the engine isn't running, the seal breaking down and allowing engine oil to attack the bearing and wash away the permanent lubrication is what begins the IMS bearing failure.

[Frodo]

Originally Posted by tnoice

So question is, would you include changing out the AOS every 60-80,000 miles AND the water pump a good precautionary measure, or is it not needed. Run it till it breaks?

Yeah, I'd be interested in the answer to that question as well. When the AOS is going, are there sometimes/usually/always some symptoms that, if you're really paying attention, you can notice before having a potentially catastrophic episode like almost happened here?

Jake, I remember you talking about 2 modes of failure with the AOS, each with their own symptoms (white smoke in one case, a high pitched squeal at idle in the other). Are these symptoms pretty much always going to precede the failure?

Might removing the oil filler cap (checking for increased vacuum and difficult removal of the cap) at idle periodically ( maybe monthly??) be a good preventative maintenance measure to keep tabs on the AOS integrity?

[JTP]

When replacing the AOS, would you get the same part number or is there an improved design? Is the Motorsport version a better solution, despite the difference in cost? Same goes for the water pump, is there an improved pump or do we replace it with the same stock pump? Is there one made with metal impellers?

[mikefocke]

Link to the water pump Jake recommends.

I don't see a unique AOS on the site.

[demick]

I've not seen any confirmation that the Jake waterpump has a metal impeller. I've seen the question asked several times, but never answered.

[Gilles]

Originally Posted by Jake Raby

Its not mileage that counts!!!!
Its TIME IN SERVICE!!!

The last M96 engine that was built came from 2005, at this point ALL M96 engines are AT LEAST 5 years old and ALL of them need the water pump changed.

Jake,

A friend of mine with an '06 Cayman S took his car to the dealer before the warranty expired (+/- 15K), but reached the four years.

The Service Mgr. recommended replacing the water pump saying "these pumps are constantly failing and will happen sooner than later, we better replace it now while still under warranty"...

also on the Cayman Club (Planet-9..) I have read of several Caymans that had a water pump failure
.

[litteng]

i just did a quick check and the pump for my 2006 has a different part number than the earlier ones, is the impeller on these still plastic too?

[JTP]

Originally Posted by mikefocke

Link to the water pump Jake recommends.

I don't see a unique AOS on the site.

Thanks Mike!

[Jake Raby]

Originally Posted by demick

I've not seen any confirmation that the Jake waterpump has a metal impeller. I've seen the question asked several times, but never answered.

I am not selling a water pump with a metal impeller.. The main reason is IF the bearing in one of these units goes bad it will chew into the engine block and destroy it.
At the current state of development using a quality pump with a plastic impeller, but changing it out every 2-3 years is the best policy.

Excellence is going to cover the water pump issue in an upcoming issue, I spoke to the Editor yesterday and he told me that they'd be in touch for my data.

[Frodo]

So Jake, back to tnoice's question (specifically with regard to the AOS):

"So question is, would you include changing out the AOS every 60-80,000 miles AND the water pump a good precautionary measure, or is it not needed. Run it till it breaks?"

And (directly related to that question) are the early symptoms of AOS failure (mentioned in my last post) pretty reliable indicators that one can wait to see/hear, or should the AOS (like the water pump) just routinely be replaced after a certain number years? If it (the AOS) should be replaced based on age alone (ie, before any signs that it's failing), how long should we go between replacements?

[Jake Raby]

The best policy is to NEVER wait for the components to fail.. Doing so ALWAYS costs more money.. If nothing else you end up spending more money due to a tow bill and inconvenience and thats if no secondary failures occur or complete engine loss.

Waiting for things to break is never the best answer.

[Frodo]

Sooooo, how often? Every 5 years? 4? 3?

And just go ahead and replace the AOS whenever you replace the water pump?

Thanks, Jake.

[Steve Tinker]

Frodo - I've read on this board of new AOS units failing within a few hundred miles, so its one of those imponderables that can vary.
As with anything manufactured with plastic and "rubber" (nothing is rubber today), everything depends on exposure to max & min heat cycles, time, engine usage, acidic value of old oil attacking the plastic (as per IMS bearing seals), etc, etc, so I think your question cannot be answered easily.
Personally, if you check your oil cap vacuum weekly, look & listen for squeaking and smoking on startup and once a year inspect for excess oil and clean out the throttle body you won't go far wrong.
If there is no history of AOS replacement, THAT'S the time to replace it before it bites you on the a$$.

[Mark_T]

Right then, I'm sold. I'll start off next season with a new AOS and water pump.

Couple of AOS questions, though. I'm looking at the Pelican catalog and note 2 says that all models up to '99 engine 65X 01419 also use 996.107.145.06.M100 vent line and 999.707.446.40.M100 o-ring.

Is this the j-tube that I have see mentioned that should be replaced with the AOS?

My car is a 99, put in service Sept. 98. Is that info enough or do I need to find this number on the car somewhere to see if these are the right parts? If so, where?

Mark