The Waterpumper Blues
Had a little boxster come into the shop last week with a big coolant leak and grinding noise. Typically when I hear “grinding noise” complaints with an M96 or M97 engine, it means the waterpump is going to be in pieces, which isn’t a good thing. I can’t recommend enough replacing these waterpumps every 40k miles or 5 years. When the impellers come apart, the plastic bits will become lodged in the cylinder heads, leading to cracking and coolant intermix with the oil. A very simple preventative fix will lead to a $10-12k repair. It is one of those spend $1000 now to keep from spending $12k later fixes. This has been the case to some extent with Porsche water pumpers since they came out. In the earlier 928 and 944’s it was preventative to replace the timing belt and waterpump every 60k miles or 4 years, and most people doing with 944’s understand that maintenance schedule. Not so much with owners who have the cars produced in the last 20 years. Eventually this will become common knowledge and people will put money into their toys to make sure they live a longer life, we just aren’t there yet. We call this the ostrich effect.
The bearing in this pump was so shot that it caused the impeller to shift, making it very hard to get the top bolt out.
The belt was about 96k miles old from what I see.
Not a bad run for 100k miles, but now there is a lot of plastic up in the engine that can’t be flushed out. The future for this motor is not long. The proper, yet very expensive fix at this point is to remove the engine, pull the heads, pull the radiators, and clean everything out. Not cheap by any means and quickly exceeds the value of the car.
The few pieces of the plastic impeller that I could find.