Page 20 - KCRPCA JanFeb 2021

NUTS & BOLTS
WATER PUMP BLUES
FROM FAILURE TO FIX FAST
TECHNICAL EDITOR KARL WILEN
As we end another hot season and move forward into the cooler weather, one thing remains the same....your water cooled Porsche’s cooling system is another year older! Since the water cooled Porsches came out back in the late 70’s and early 80’s, it was common knowledge to replace those water pumps on a regular basis as preventative maintenance. Back in those days, the water pump rode on the tim- ing belt, and a pump failure could have catastrophic effects on the motor. While the mechanism is slightly different on today’s en- gines, the results of a failed pump can still have a big impact on your wallet. I’ve touched on this sub- ject before, but feel it is important to stress this again as new buy- ers are attracted to these cars with their affordable buy in pricing.
See Picture 1
While there is no timing belt to worry about on the modern water- cooled engines, the pumps still fail as often, if not more. Symptoms of a failing water pump can mani- fest as a “pulley noise”, grinding noise, or a small drip of coolant underneath the car. It might even burn the belt and cause a rubber smell as the pulley wobbles and eats the drive belt.
Here you can see the water pump location on an M96/M97 engine with the front access cover re- moved. This pump’s bearing had starting play, allowing the impel- ler to make contact with the pump housing and shatter.
See Pic 2
The factory pumps come with a plastic impeller which can explode apart once the bearing starts to get play in it, and it can send those little plastic bits through your
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