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  • Porsche Club
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  • Present cars
    2006 Audi S4
    1988 928s4

ebk5368's Achievements


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  1. There is a fuse (row b, fuse 10 I think) for the gauge cluster. Also, if my weak eyes are reading the wiring diagram correctly, the control unit for the HVAC may also be affected. Make sure to check it before spending too many $$$.
  2. I posted this a while back but it explains why the error is there and why fixing it is hard. ************************************************************************ I spoke with a friend familiar with the instrument cluster system. The cluster controller receives a speed signal, typically CAN data from another vehicle controller, and then converts this via an algorithm into both the digital display value and the pointer position. It appears to be a linear function but it doesn't have to be; for example the graphic scale could be expanded on the lower range, of middle range, or upper range, depending on the manufacturer requirements. In the case of my S, such graphical trickery could be useful as the scale covers 175 mph in a 180 degree sweep and is pretty much useless as a ticket avoidance device. The difference between 35 and 40 is pretty hard to see. And also note that the display and pointer position are hopefully matched to avoid user complaints. To cover any manufacturing tolerance in the dial graphics, and to insure the legal tolerance range is met (remember that tire model, wear, and inflation all have influence), an offset in the algorithm function can be introduced by the system designers, the goal being a skewed tolerance to make sure you don't get a ticket for going 64 when your speedometer says 60. The instrument controller algorithm is not adjustable by mortals. The odometer may or may not have the same issue as it may be driven by a different algorithm and there is no skewed tolerance concern. Having said that I've checked my odometer on long distance trips and it seems to be plus about 4 miles every 100. It could be possible to trick the system with different tire size, or by finding the source of the speed signal and assuming it counts pulses from a toothed wheel, add or subtract pulses, but this would only fix a specific speed error at one point because such a 'fix' would introduce a percentage of value error and the speedo would only be accurate at the one point where both the curves cross. For example, if as built it is always ~~4mph high. If I increase the tire size by 6.25%, then at 64mph the indicated speed and actual speed would be equal. However, at 120mph indicated, actual speed would be greater, and at 30mph indicated, actual speed would be lower. An interesting subject but not an easy fix apparently.
  3. As my old crew chief once said, "...if it ain't broke don't fix it..." No help there if you really want to clean it...but it's an ugly job on a 986. You have to protect the interior and top, especially the back window, from splashes in addition to the electrical stuff, plus you need to take care of the engine compartment insulation (don't soak it). I don't know how deep the concours guys go, but I did some cleaning the other day as I was changing the water-pump and this worked pretty well: With the car on high jackstands, with the undertray removed, with the access panel behind the seats removed, with everything wrapped: - I used two hardware store spray bottles, one filled with a mix of hot water and mr. clean, the other with hot water. I heavily coated the areas to be cleaned with the cleaner mixture, worked any tough spots with a toothbrush and my fingers, and then flushed with the warm water. I took care not to leave the cleaner on too long and after it was all done made sure to run the car to evaporate any moisture. (An important point here, whatever you use to clean the engine, when you start it back up the fumes will fill the interior of the car because all the access hatches are open. You could end up with a clean engine and a seriously stinkin interior.) I only did the front of the engine this way, doing the complete engine would be a real mission. Or you could just wipe down every thing you can see with a rag and close it back up.
  4. I had the same problem a few months back. The solution was the point in the electrical system shared by both left and right sides; the headlight switch or the ignition switch. The headlight switch won. The illuminated ring around the headlight switch is delicate and finicky to assemble, take your time.
  5. The voltage regulator was the culprit. I may be the only guy who changes the voltage regulator as part of a coolant refill! It was a good learning experience. )-: 1) The water-pump was leaking but none of the coolant was dripping onto the floor in the garage. Instead, it was getting on the belt and burning off on the front of the engine. What little dropped down was collected by the under-tray and then burned off. the clue that made me look was a small drop in coolant level and a funny rotating noise from the pump bearing at low speeds. 2) Changing the water-pump was pretty easy. I didn't remove the seats and the hardest part was getting the under-tray off and on. 3) Mr. Clean and a tooth brush worked well to clean up the mess on the front of the engine, followed by warm water rinse, all administered by a hardware store spray bottle. 4) Draining and refilling the coolant went well. I used the drain plug in the bottom of the water manifold; it took a while because I didn't pull the vent hose but I wasn't in a rush. I measured the amount I drained out, 3 gallons, so I could make sure to put the same back in. I used Havoline Dex-cool extended life for the refill. With the vent valve open, and starting the process with the reservoir full to the top, on engine start-up the system immediately drank almost 1 gallon as fast as I could pour it in. Afterwards, closing the radiator cap and warming the engine at 2000 rpm until the thermostat opened, and then running until the radiator fans came on with short bursts to 5000rpm, it really didn't drink much more coolant. After shut down, I closed the vent valve, topped up the reservoir, and it was done. Sort of. 5) If I had to do it again I would not pull fuse B1 as suggested in the service manual. It didn't feel right then and now I'm sure. Without the 12v input from the Instrument Cluster telling the Voltage Regulator how to balance the output, the VR apparently died trying to do the job. 6) If you want to know how a charging system works some of the best sources are from the hot rod world. Google was great help for a guy whose electrical expertise ends when the smoke gets out. 7) The repair shop who tested my alternator out of the car didn't believe it was broken and proved it. The failure mode took a few minutes to manifest itself as the VR dropped the output to zero. Hopefully I can get my $20 back. Those guys cost me a week of head-scratching and heartburn. Here's to Martini's as a diagnostic tool. 8) Thanks to this site I was able to find a new Voltage Regulator. The original unit was an F-00M-145-225. There are no apparent cross references published to the Porsche alternator, but you can trace it to a lot of Audi's and VW's. The VW Beetle was the car I picked as my choice cross reference. Discountvdubparts.com listed the Beetle regulator under their part number W0133-1613555 for $67.95 (this is a common price on many sites) so I took a chance. The part arrived as an original Bosch p/n F-00M-145-350. I wasn't 100% sure if this could be used so I went back to Google and found a French repair shop that actually cross referenced the 2001 Boxster and both part numbers as being correct. So far it works… 9) Removing the Alternator was probably the easiest part of the job. The key seems to be backing the mounting bolts out about 3 turns and then tapping them on the head with a soft drift to knock back the bushings. Then, with a little patience and rotation, it falls right out. 10) Changing the Voltage Regulator is a simple bench-top job, remove the two big nuts on the back, and the two screws holding the back-cover on, and you can then access the three screws holding the VR down. Just take care with the brushes when you reinsert the new unit. I think the root cause of all this evil goes to putting water in Porsche engines. If this car or my old 928 are any indication, Porsche water-pumps appear to be a regular service item. $250 (water-pump) + $50 (coolant and gaskets) + $91 (VR w/shipping) + $20 (useless testing) = $410 (not including Vodka)
  6. Update: The generator repair shop tested it out of the car and said it worked ok. On the car, the the voltage regulator 12v signal from the instrument cluster (key on) is present at the generator plug. The cable from the generator to the battery tests ok. I cannot find any broken fuses. Back in the car, initially after startup it charges at > 13v. However, after a couple of minutes the charge drops back to zero and the battery starts to discharge. No battery indicator light ever comes on, nor any other telltales. My next step is to replace the voltage regualtor. E
  7. I replaced my 01 986 S Tip waterpump this week and completely flushed the cooling system. Following the factory manual instructions, during the initial stages of the refill, I pulled fuse B1 (key off) per section 19-14 to force open the coolant shutoff valve. This instruction was for Tip cars only. Fuse B1 covers the instrument cluster and tiptronic, PSM, TC The refill went well with no problems. Afterwards, I discovered the alternator is not charging. I have not completed any serious testing, but I suspect the voltage regulator has been killed. I also suspect running the engine up to temp with the instrument cluster off is somehow responsible for killing the alternator. Has anyone had a similar experiance? If what I suspect is true I wish I hadn't read the manual so carefully! Signed, cool but powerless in Seattle.
  8. I've put about 30,000 miles on an 01 tip and have the following experiance: • For city traffic, I don't worry too much and let it do its thing. Under typical conditions it shifts at low RPM (lower than yours) and doesn't get too exited. If I keep my boot in it, it runs close to redline. I recently had a chance to run from a stop sign to 130mph plus and the shifting was probably better than I would have done as a casual amateur. • I have noticed the shift map change to more performance oriented setting; it holds in one gear, down shifts early, shifts at higher RPM, etc. But I still haven't learned when it will make the change so I usually flip to manual if I need a specific gear. I believe there are 5 maps but I can only tell the 'basic cruiser' to 'performance' change. • Triggers appear to be related to throttle rate of change (on-off the gas faster), throttle opening (big), steering angle (?) seems to have an affect, maybe from its PSM option, and time between throttle off and brake on (fast transition). One of the other members can probably give some input on this point. • It has an odd habit of shifting up a gear at low RPM, low load, just when you step back into the gas. Apparently it shifted down a gear on the brakes and then decides to go back to a low rpm mode when you tip back in. I don't know of any trick to get it back to performance shift map other than driving it hard. I've rebooted the main ECU a couple of times with a battery disconnect (working on other issues) and didn't notice any change to the shifting action. The trans controller may remember the last map it was on. For me the tip's main problem is that it works best when driven hard, but with a fast car it's hard to keep a license while keeping the tip in the game. The rest of the time it's an average automatic. Of course where I live, with city traffic, that's not so bad. I can't wait for the new double clutch automatic-manual.
  9. I have an 01 tip and I seem to recall there was a service bullitin to adjust the shifter cable.
  10. I've checked my speedo at a number of different speeds and it appears to by a 4mph offset and not a percentage of the speed. The state of Washington has installed a number of speedometer calibration checkpoints just for this purpose, they look like a speed limit sign with a digital display 'Your Speed IS"... (-: They seem to work at almost any speed. As I understand the 986 system it is not adjustable and can't be recalibrated. If some one online knows how to adjust it, please post as it looks like some of us would like to work on it.
  11. I agree with Highlander. And I would also say it's a real bonus to have a guy who actually knows what Akerman and Castor are. If he can fix your bump-steer problem we want to know more. The comment about letting the car settle reads backwards to me; the car is settled with the full weight on its tires, not on the jack. In fact, at least on my 928, you have to pull the car down to its correct ride height in between adjustments before you can take a measurement. For me I always liked to roll the car forward and backward a car length to make sure we had everything settled back down. There should be some alignment guys in your area who have Porsche experience and some good references. And getting it done right is worth a bit of extra cash. Especially the silly details like getting the steering wheel centered (-: Be sure to ask for the 'before' and 'after' settings report so you can see what changed and where it was out. And if you're really interested in alignment, Carroll Smith's book, "Tune to Win" is worth a reading.
  12. I had some very bad experience with mixing tires on my 928. I replaced the rears with the exact same brand and type of tire, only 2 years newer, and created a really scary ride. It felt like the rear was only following the front to see what would happen next. The grip was ok but the turn-in dynamics were spooky. Be sure to find a good tire guy to do the mounting and balancing. Tire Rack used to have a nice section on the website with reviews for tire shops. Look for the guys with a lot of positive reviews and wide, as in wheel width (-:, passenger car wheel experiance. Busting tires is a tough job and the good guys tend to move up to better jobs (like management) as soon as they can. I found a guy in Seattle whose core business is wheel repair and he manages his own business. Also. you didn't mention Conti Sport Contact 2's. I've had good luck with both roundness and road noise on my 986 and 928. I can't make any claims for grip but they're good enough for my daily summer driving.
  13. Back in the mid 80's I used to rebuild BBS race wheels. We used 144 inch/pounds torque and only with new bolts. I've never worked on a road wheel, but we always replaced the seal ring/o-ring between the halves. BBS has an office in Braselton GA that can answer questions.
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