Cooling System Maintenance
> I have an 84 928S that just today started running hot.
> The water was a bit low, so I filled it. Nice and green looking, no rust.
> No apparent leaks. Any ideas?
See if adding coolant helped. You might also try to bleed your cooling system. I did this by parking the car on a hill so that the radiator was higher than the engine. Turn on the car and then loosen the 3/4" fill hose that runs from the coolant fill tank to the top of the radiator. Pull the hose of just enough so that you can see air bubbles escape without letting a bunch of fluid leak out. When there are no more air bubbles, push the hose back on and tighten the clamp. (Thanks go to Devek and the instructions included with my radiator for tips on bleeding the system.) BUT, there's a good chance that your water pump is on its way out. My car had run hot for a while, but since I replaced the pump, the car usually runs near the center of the gauge.
> Now the newby part....
> Just where the heck is the water pump? I looked in all the spots my
> non-porsche's have had one, but could not find it.
> How hard is it to replace?
The pump is located behind the timing belt cover and is powered by the t-belt. Replacement is non-trivial since you have to remove the t-belt and then make sure the belt is retensioned precisely during reassembly. The golden rule is to always replace the water pump and t-belt at the same time, regardless of which component actually needs service. Also, make sure the person doing the replacement has the proper ($400) tensioning gauge - no exceptions! Expect to pay in the neighborhood of $600-$800 for replacement of the belt and pump (which includes the cost of the belt and a quality PCNA rebuilt pump). Be sure to check the condition of the tensioner and guides during replacement. Finally, the belt will have to be retensioned 1500 miles after installation. Most shops should include the retensioning costs in the initial installation bill.
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