Contour Enthusiasts Group Archives Forums General Troubleshooting water pump replacement and belt

I replaced the black plastc impellar pumps on 2 1995 V6s. Both were prior to disintegration, and one had cracks. My theory is that Ford molded the impellars from glass filled nylon. What got to the pumps over time was the water. Nylon has great properties, but will degrade over time in the presence of moisture. I think the term is hydroscopic. The white plastic could be one of many newer polymers,(maybe not as cheap and easy to mold as nylon) and never have a problem. I replaced mine with the GMB DuroPro metal impellar type from NAPA, yet NAPA's standard variety has the white plastic and costs more.

Since you have 50K on your car, I would recommend that you change both the water pump belt and the serpentine belt just to be on the safe side.

I hear that Autozone sells a water pump with a metal impeller, but I've also come to find out that the impeller isn't the part that fails first. There's some sort of shroud (cone?) made of metal that, over time, loosens and slides into the impeller. Since the cone is metal, and the (stock) impellers are plastic, the cone shreds the impeller, and forks up your cooling system.

Also, I was wondering if this has been a problem on newer Contours and Mystiques. I personally own a '99 Mystique with 45k on the clock and no problems so far. Is this pump going to fail on me, no matter how nice I am to the car? Should I go ahead and replace it with the Autozone special?

---Shifty. He has no mods.

There has been much info in the past on the cause of waterpump failures. The cone is real. It is a thin stainless steel cone that is "metal staked" to the aluminum housing. It is in close proximity of the impellar blades to create the suction. If it breaks loose it will aggravate, or cause the failure, however many impellars have broken apart without the cone coming loose.
When you replace the pump, check out the cone. Put your finger in the center and give a little tug. It should be tight. If it's loose, or falls off, you will need to replace the whole pump housing, and that's only available from Ford dealers or parts supply online. The new Ford unit should have the "improved" plastic impellar. In any case, don't leave a loose cone alone, even with a metal impellar.

So far, I have 101,000 miles on my '99 Mystique water pump, with no problems. Two Ford service managers I've talked to swear they've never heard of any unusual problems with these water pumps. I've heard that sometime between '98 and '99, Ford switched to a nylon impeller, instead of the black plastic model. I've also wondered about excessive RPM's being the cause of the impeller failures. I rarely take my RPM's over 3500, although the redline is 7,000. I've wondered if aggressive driving is somewhat the cause of the premature failures. Routine high RPM driving might destroy the impellers quicker than "normal" driving.

I treat my car like it's going to fall apart any second. Drive it like an old man. The one time I was really hard on it was when racing a girl in a '98 Cougar. Whipped her, too, thanks to my MTX. Traction control didn't hurt, either.

It sounds like this water pump cone is the problem. Is there an upgrade for it? I mean, if they keep falling off, you'd think Ford would have a recall notice.

Originally posted by Beachboy:

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... I've wondered if aggressive driving is somewhat the cause of the premature failures.

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I had to replace both of my waterpumps in May due to disentegration, I would dispute your theory based on my cars' usage. Impeller failure seems to start with radial stress cracks in line with the 2 small (anti-cavitation ??) holes.

Shifty:
Cone is a problem, but not the problem. Both of mine were firmly in place.