johnkuz

I believe that the water pump in my 04 66k mile 996 May be leaking. Have checked everywhere for the source of a antifreeze odor that only seems to occur after running for 20 min of so. Couple questions
1. Metal or plastic impellers
2. Brand.

I am a firm believer when you replace a part replace it with the best there is. Recommendations?

relinuca

In 02/13, I replaced my '99 996's water pump as a "peace of mind" action. I still have the original pump with its plastic impeller, and the replacement pump was another OEM unit w/plastic impeller.

The old pump still looks like new and shows no signs of impeller wear or seal leakage.

As other rennlist posters will probably advise you, the source of the coolant odor you mentioned is most likely the coolant tank.

relinuca

relinuca

Oh, I forgot to mention that the replacement occurred at 67K miles.

johnkuz

Had the coolant tank replaced at 60k. New cap, and hoses checked. Puzzling.

Rubik

Have you checked the area around the water pump for any coolant traces or "water spots"?

911661

plastic impellers
OEM water pump
you do not want the metal impellers, because when the pump fails you do not want metal impellers scoring the inside of your engine.

fpb111

So after reading the above replies to your question the consensus is:
1. If you think your water pump is leaking replace your coolant tank.
2. OE or OE type with plastic impeller is best.

kromdom

my 2 cents: pressure test to locate/identify the source of the "leak"

Ahsai

+1 and I would also replace the pump with OE if it's original. Good price for parts at ECS tuning and Sunset Porsche.

Macster

Get the car in the air and carefully inspect the water pump for signs of a coolant leak.

If it is leaking, and it probably is (I say this after reading you have replaced the coolant tank and the cap), replace it with whatever the dealer's parts manager shoves over the parts counter at you.

My 2002 Boxster's factory water pump lasted 172K miles and its replacement is ok at 288K miles.

My 2003 Turbo's water lasted nearly 125K miles.

Neither water pump showed any signs of impeller problems. The Boxster's water pump was noisy. For the Turbo, it was a strong odor of anti-freeze that clued me in the water pump might be leaking and I got the car over to the dealer and on the lift pronto and sure enough there was a blob of dried anti-freeze residue behind the pulley.

Might mention both replacement water pumps had the same impeller material as the original water pumps.

Rgardless if the leak is from the water pump, a prematurely bad coolant tank or cap, or some other place, you need to get the source of the leak id'd and addressed and ASAP.

Meares

heater core?

cobra935o

My AOS went right about the same mileage you have on my 04. It was a little tougher to diagnose since it only started to spray out of it when it was hot, the coolant was all over around the back side of the motor by the drivers side rear wheel. As far as water pump, I did that a few miles after, but I did a metal impeller pump, so I dont ever have to worry about plastic coming apart in there again as it did with the first one. I have been working on cars (and airplanes) for a pretty long time, and I have never ever seen another pump with a plastic impeller on any other car before (I am sure there have to more out there). If its the water pump though there will be no question of where its coming from, the coolant will be coming out the bottom of the pump on the front of the motor.

Hurdigurdiman

When I DIY'd my pump early summer this year at 70000 miles, I tried for an After Market pump approx $250 but out of stock everywhere. I went for the Porsche Original at $400 along with low temp Thermostat. No loss of coolant since after 3000 miles. The old one would leave an egg cup of water on the garage floor directly under the pump after a cold start and also as it cooled down after a run. The water was coming from behind the water pump pulley. I didn't notice if the new or old pump had metal fins or not. It was Porsche Original. Anything good enough for PORSCHE, is good enough for ME. (How is that for advertising ?) LOL

johnkuz

Thanks all. I have a pressure test scheduled for Tuesday. We will see what they say.

RngTrtl

...except for the thermostat