I’ve got power steering whine, and if you touch the PDCC lines under the hood near the reservoir, a vibration (I’m told that is a clear sign of cavitation and pump failure). 2009 CTTS ~85K, new to me about 1K and 6 months ago.

I just paid a shop $800 to put in the $2,200 pump… and the noise persists.

so I am hoping for your best suggestions on troubleshooting this.

some things to note and possible theories:

1) I did the steering and pdcc fluid change about a month and 200 miles ago. Possibly slurped some air pdcc side during the fill. I used the method of plumbing return to a bucket, filling reservoir with new, and turning engine over for a second then right back off. One of those ran a second long end slurped air. Subsequently filled, ran the bleed and calibrate programs with my Foxwell nt530, no air in reservoir, and noise did not start immediately after. I don’t think this it it?

2) used pentosin chf11s instead of 202 b/c that is what FCP Euro sold for this application. Upon asking Porsche, the original fill, and still the recommended fill, is 202. Fixed below with new pump, and will use 202 going forward.


3) I recently did an oil change, including moving the PDCC expansion loop out of the way, and then zip tying it back (like most: missing the bracket). It is fairly loose in there, so I don’t think it is linked to the issue but maybe? (Easy enough to eliminate, I’ll have the shop cut the zip ties.) it started soon after this.

4) at same time as oil change, I noticed this pressure line (below) was not set in its clips. Used a pry bar to try to set it in. When it “snapped” into place, I thought I had just snapped the clip which broke at that moment. Is it possible I cracked the inside of the line or knocked something loose?

line #4 (the middle section, which is black and feels like hard plastic, not the ends which are metal), and clips #13 in this diagram:




5) paid indy shop to confirm diagnosis of faulty pump, and R&R if they agree. They did, and did. They also botched the job, as steering fluid is leaking from the “banjo bolt” pressure side of the pump (at least that is where we think it is leaking from, but it is certainly leaking from somewhere near the pump). Needless to say I’m upset; they have not been awesome on this job, and now I’m guessing they have a lot of hoses to replace given the fluid is everywhere down there.

So the noise and vibration persist, and the reservoir lost about 2 inches of fluid on the 20 min drive home and overnight.

so maybe they failed to bleed properly (though this seems hard to do), or I got a bad lump directly from p-car dealer, or the leak at the banjo is the new source of the same noise? (Is the banjo, parts 3,4 and connecting pressure line 1, the power steering side or the pdcc side?)



Is the banjo, parts 3,4 and connecting pressure line 1, the power steering side or the pdcc side?

Is this more likely a pdcc component like a valve block or whatever they call the actuators in the middle of the sway bar? Did the flush maybe work something loose that is causing cavitation somewhere else in the system?

any and all troubleshooting suggestions welcome!

 

Bump… any ideas?

The shop is pulling it back apart to fix the leak, which seems to be on the steering side not the PDCC side..

I’m worried that even when they finish, the issue with the noise will still be there.

thanks In advance.

 

It was the banjo bolt leaking. Maybe they used the wrong crush washers (they used shop supplies, but are going to use the Porsche ones this time), or maybe they did not clean or torque it?

Still unsure why the vibration (cavitation?) is still there.


here some pics of the area.

 

Bonded sealing washers work better than crush washers. You can get a whole metric set on Amazon for about $20. I've had crush washers leak before and replaced them with these bonded sealing washers. I've never had one of those leak, even when crush washers would. I've used them on motor oil for drain plugs, gasoline on a fuel distributor, etc and haven't seen them break down due to chemical exposure. The PDCC system uses mineral oil so even less harsh than gasoline. Would probably hold up just fine if you still have a leak there.

https://a.co/d/46lfWHv

 

Following…as the Silver GTS has a PDCC system fault, currently at the back distribution block…but similar vibration at the reservoir as you describe. Local Porsche dealer master tech says he hasn’t seen any issues with any PDCC system in the years(10-12?) he’s been there, and the other Indy that theoretically specializes in Porsche’s…the service writer asked me what PDCC was.