MP4.2+6.0

hopefully it has the hydraulic in it. I can't be sure if G004 superseded G002 in Audi's nomenclature; parts counter should know. If by chance you are looking at ecs's site which says that, I would not take that as authoritive. In the same pages, they don't seem to understand fully (or at least communicate) what Audi did transitioning from the older mineral oil to the synthetic variey in the late 80's. Here's one site that gets into this: http://www.sjmautotechnik.com/troubl...sp.html#hydoil. Blau parts has a page too: http://www.blauparts.com/vw/vw_fluid...ic_fluid.shtml They get into practical experience about intermixing the older 7S stuff and the newer synthetic. As they say, Audi said way back when that was okay to do (I owned the 5000 when that change was underway), but Pentosin's can labeling says no.

Meanwhile to your question, obviously get the fluid level right for starters, and w/ the current spec hydraulic fluid. If any doubt, change it--Audi specifically says not to use Dextron based fluids (American cars generally, Toyotas and various others). And yes, it gets pretty black over time. The only filter in the system is in the reservoir typically, and it isn't much to catch anything other than the biggest junk that could come out of a rusty can or some such unusual case. My car remains under CPO and extended maintenance so I have left it be, but once it's mine to maintain in full, I plan to change it. Have done so on the C5 4.2 and my older C4, and along the way have learned how essentially to power flush it and avoid any bleeding or dry running (death to the pump in short order). The fluid is relatively cheap and not a lot is needed, particularly when compared to the mess and nightmare of a failing or blown steering rack or difficulty changing the not inexpensive pump.

MP4.2+6.0

http://www.pentosin.net/pressrelease..._CHF11S_V3.pdf

Sure enough, looked at O'Reilly's web site and found it at my local store as I thought I had noticed recently: http://www.oreillyauto.com/site/c/de...4184&ppt=C0031 Net of shipping charges, the corner brick and mortar store may be the cheapest (and fastest) option here. Or again, the dealer price may not be that far off either for peace of mind.

Iron_Mike

@MP4.2+6.0: thank you for all your info, very helpful. btw, the fluid itself is not black, the power steering fluid container is black (--> painted black) and therefore i cannot determine by color what type of power steering fluid is currently in there. I dipped top of my finger inside, it appears yellow / transparent or green... hard to see...

Do you have any theories on what might have caused the malfunctioning today ?

Thanx again for your help !

- M

Iron_Mike

Update:

As i wrote in my initial post, the malfunctioning stopped after the car stood for app. 3 hours.

Today I did another little test drive. When I started the car, no problems / errors popped up. After about 15 min of driving, ABS, ESP & parking break message popped up on the dash...

It appears that the problems are only popping up when the car has run for a little bit.

Is it possible that this is an overheating issue that triggers the problems ?

- M

P.S.: will bring it to the dealer tomorrow and read out error codes...

Mike_k

It's an electrical component so it's very possible that it might be overheating and then failing. Either way though, it's going to require replacement, regardless of cause. It's a non-servicable part.

I'd second you not losing power steering though. If anything it defaulted to the firmest setting .

Iron_Mike

@Mike_k: well, the first time the problems occurred (--> my initial post), steering was noticeably harder when I restarted the car (after it was parked for 5 mins)- not sure how much power steering aid was still left.

When the problems occurred again today during my test drive (while I was driving), I noticed that the power steering was still there (although ESP, ABS and parking brake light were on). I continued to drive for another 5 mins and at one point the steering got noticeably harder, although still manageable - so u might be right that it defaulted to a diffrent power steering setting (I didn't even know there were different power steering settings).

I'm guessing there's either a short somewhere, that then triggers the problems - or overheating as I mentioned before. Since the problems occur when the car has been running for a bit and they don't go away until the car has cooled off, overheating seems to be the problem.

How could this be diagnosed / inspected ?

Would the vagcom system return error codes that we could trace back to overheating ?

The dealer (I am bringing the car to tomorrow) can read our error codes, but they are not a repair shop, hence they got limited knowledge so I wanna make sure I come prepared...

Thanks again for your help !

- M

Iron_Mike

@mike_k: btw, which "non-servicable" part are you referring to ?

mishar

Dealer with limited knowledge that needs wisdom from this (or any other) forum and bad power steering are not very promising combination.

Generally speaking it is way more likely loose than short contact. Only way to even start seriously thinking about it is VCDS (VAG-COM) scan.

Iron_Mike

@mishar: yes, I totally agree.

there's is actually a little bit more to the story - typical crazy car story...:

I recently purchased the car, the car dealer (who was very nice and said that they were NOT a repair shop) told me, after I asked him if they found any issues on their inspection on the car when they got it, that they replaced an ABS sensor. he said everything else was good, maintenance records (by the former owner) look great and they are all there.

I test drove the car 4 times (!) (always 5-8 min drives). I did a pre-purchase inspection by a AAA certified shop (very cheap for AAA members), they found nothing major. they also test drove the car (ca. 5mins) - NOTHING.

I buy the car, drive it back home (25 min) and the malfunctioning occurred... what can you say ?!

Another theory that I have is, that the mechanic who did the inspection maybe loosened one of the ABS sensors (not sure if that would trigger the symptoms I'm experiencing)...

anyways, will get the VCDS codes tomorrow morning and will update...

mishar

I think they already did that scan and it pointed to that ABS sensor, but something else too. Like ABS module, for example. They changed easier and cheaper one and it looked fine. Unfortunately just looked. I am coming back to the loose contact (my experience). Hopefully it's just that. Cheap but difficult to find.

Take some USB memory stick with you and try to make them to save a copy of that scan for you. Upload it here.