Ive had aproblem pop up recently and progressed semi gradually (like over a span of a month) that I wanted to check about before biting any bullets. I have an 86 that when I first start it and make the first turn of the day the pump whines very loudly and vibrates the steering wheel and doesnt really offer much in the way of power assist. After I make that first turn though it is almost cured and by the time I get out of the parking lot it is silent again untill the next COLD start. Is this the pump dying or something else? Maybe a seal or something? I might just buy a seal kit if I had the time to waste if it happened not to help anything, but I cant justify that without some clarification. The car has 104k miles.

 

When did you last flush the system with new fluid and replace the reservoir/filter?

 

Sure sounds like the filter, part of the reservoir is starving the pump for oil when it is cold, the circulating of the fluid due to the engine running improves it enough that it no longer is cavitating.

Replace the reservoir, replace the fluid in the process and let us know if that doesn't fix it.

 

This is exactly the behaviour I had on my '89.

First turn of the day would whine as if there was air in the system, then quiet and some power assist. However when I drove another local '89 I was surprised at how light the PS was, especially as I didn't have the restrictor (got my high pressure line rebuilt recently).

Finally got round to rebuilding my PS pump using a seal kit, and whine cured, plus I have slightly more power assist than before.

Your '86 has the exact same PS pump as my car (was same from around '83 I recall, until '90 when Porsche changed to a higher presure 100 bar pump instead of 75).

The seal kit is actually a very easy install - trickiest bit is taking the PS pump off. Make sure you get the nylon wiper and associated rubber bow-tie around the right way (take note when you open up the pump - I have pictures somewhere of the whole process).

 

I'd check belt condition and tension first. If you've got no fluid leaks at all, and your resevior is topped up, you might get away with correcting the tension. Upon start when cold, the belt (if loose) will slip on the pully until the friction softens the rubber surface of the belt and grabs the pully fully. The vibration you are feeling could be intermitant pressure at the pump before the belt hooks up.

 

I did not know there was a filter, where is it?? I'll try that first, then go for the seal kit. Is there any way to inspect the ps filter (the way this car was serviced it may have been done)? Fluid looks bright red, but I only have 2.5k of my own miles on the car so I cannot say when the fluid was flushed although I think the rack was replaced not long ago by the looks of things, so with that goes a fluid change. BTW running the engine at say 2k rpm only makes the whine louder so it's not from low pump speed.

 

The filter is part of the reservour and cannot change it separately, you'll need to change the whole reservour.

 

At less than $20 the reservoir is a consumable.
Worth a try before you dig into the pump.

 

Hasn't been mentioned so far on this thread - use Dexron ATF, not power steering fluid in your 928.

Have you checked the belt condition and tension yet?

 

Thanks Wally....i didnt want to hijack but was going to ask the question.....i DE my 87 and towards the end of the day the power steering is whining/groaning and less responsive....i suspect it is from getting too hot...is there a fluid, much like Motul for brakes, that would help with power steering.
87 euro auto