Re: Here's the evidence, where is the problem?

A few weeks ago I had to add power steering fluid.
At the track last weekend, the car started smoking and it was leaking oil droplets through the slipstream up onto the rear bumper.

So I took it apart today and found that the overflow hose from the power steering reservoir isn't connected to anything (see pic).

Is that possible?

Or is the reservoir leaking from the bottom?

Common problem at 64k miles? Your thoughts and comments would be appreciated.

Mike

Excess pressure in the system caused overflow. I don't think that's a big surprise or a problem unless it is chronic. Have you ever replaced the fluid?

Doesn't an overhead overflow tube make sense, though, rather than having fluid discharge to the ground? Since evaporative emissions, waste oil, et c. are a concern, I'd think so would PS fluid.

(And Happy New Year, too.)

the reservoir must be leaking given the volume on top of the engine.

Hard driving on the track can "overheat" the PS system. It's a not uncommon failure mode. It can result in melting of a particular plastic fitting where a metal high pressure return line feeds the lower PS fluid reservoir. When the fitting melts, the seal of this connection to the reservoir is leaky. Where it leaks is pretty much at the front top of the engine block -- top and dripping down the front. This could be what you are seeing.

On Spec Boxsters it is almost considered a requirement to install an underdrive pulley. It turns the accessories slightly slower, and this reduces the PS pump speed and temperature. It has no ill effect on alternator behavior nor water pump effectiveness.

If memory serves, if the fitting is leaking, you *can* just replace the lower reservoir half. It doesn't require replacing the pump itself nor the upper reservoir.

Good info; the hard core track guys usually do the UDP to protect the PS system a bit and some add a PS cooler and insulation around the return lines lines to better isolate the system from heat..

I recall a guy on the old Pete's Boxster board (Docta Boxster?) that tracked his 986 S a lot and went through a couple of power systering pumps under warranty till Porsche said No Mas!

Finally, I've heard driving style at the track might enter into this (as well as the track layout); if you're continually "sawing" in turns (adding input) rather than a steady turn, you may be prone to overheating the PS unit.

Thanks for your help guys, it makes sense.

So in the drawing below, is the lower reservoir half item #8?
Or is it the bottom of #1?
I tried taking #1 off but I can't seem to get that collar that goes over 4, 5 & 6 to do anything but spin.
Tight working quarters too.

Yes, the lower reservoir is #8. I think the hard line enters at the back of it (not shown in photo) which is where the leak-prone fitting is. Perhaps making the heat problem worse is that the return line zig-zags around under the AC compressor, so it gets sandwiched between the AC compressor and the engine block, absorbing lots of their heat by near or actual contact. Wrapping that section with heat insulating tape might help. And of course, on a race car the AC compressor probably gets removed anyway.

Maybe the thermostat change too.
Thanks to all.

it kept overheating until they realized the water pump was cavitating the coolant. By switching to either a less aggressive vane profile (or a reduction gear?) they got the car to run cooler. Don't recall if they were successful in hitting 200.