Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

DWS964

Contributing Members
  • Posts

    20
  • Joined

  • Last visited

Everything posted by DWS964

  1. I just replaced both LCA's, with the left side having a bad/squeaky ball joint. I found the camber (0.3 deg change) and toe had changed on the left side, but not on the right. I would suggest the alignment.
  2. I have considered this - perhaps the power steering fluid and rack warm up? I have been unable to detect any play in the tie rods, or any other part, by the time I get the car on the lift and get under and around it. I had my friend drive the car and listen/feel for the noise. Our conclusion was that is was more of a creak/binding than rattle. Thanks everyone for the input. Bottom line is that i just need to pull some parts out and get to the bottom of this.
  3. The car has developed a noise in the left front suspension. Well, in the left front corner. I originally assumed it was a loose sway bar link - that kind of noise. The odd feature is that the noise is not present when the car is cold. It only shows after being driven for many miles and something warms up. During the recent cold blast when the daytime temperatures were still around 10F, I did not hear the noise at all. Now that the temps have gone above freezing, the noise is prevalent after driving the car for a while. I sometimes wonder if the noise is more of a "binding" noise/creak than a loose thunk/rattle. I have noticed a problem with what I assumed to be the front springs binding when turning at low speeds. (once again, this was more noticeable when warmed up). I suspected bad upper shock mounts, or that perhaps the thrust bearings were missing from the installation of the PSS9 suspension (common mistake apparently). I put the car on the lift, and sway bar and control arm and shock bolts are tight. I might drop the shocks out this weekend to see if the upper mounts or thrust bearings are bad. Why would the noise increase with temperature? I have thought about CV joints - but the sound is not quite like the clicking/binding sound that I recall from my FWD Honda's with really high miles, torn boots, grease gone, worn out.. outer CV joints. But then, I really noticed it this AM at low speed coming into the parking lot, but both while driving straight and when turning. Perhaps more frequently when wheels are straight ahead. I will get a thunk on as little as the 3/4" lip entering my garage. Still unsure if it is a loose rattle, or a binding noise. The 996 is relatively low miles - 65K, CV boots all nice, etc. I do not recall seeing many front differential problems being mentioned here. Another hypothesis is steering rack or tie rods. Found one reference here on RT with inner tie rods as root cause. Suggestions? Driving me nuts. THANKS
  4. yes, latest software - v6.x No ABS faults. I assume any PSM faults would come under the ABS codes section. I do not think that PSM nor ABS lights flash during the event, but I am not looking at the dash at the time. THANKS
  5. Yes, the car has PSM (all C4's have PSM, I assume?) Sadly, although the car has a supercharger installed, it is not achieving major torque increases - so I am inclined to rule out that failure mode. I was tempted to turn off PSM and see if the failure continued to surface, but didn't want to take chances on a new track. I am trying to make the connection to hard braking. But it may be something in the PSM, which I assume is collecting signals from brakes, wheel speed sensors, throttle setting, ...etc. And there is the connection between a bad MAF causing PSM and ABS lights to come on, that I have experienced. So, I will go after the MAF (cleaning or swapping) and the Throttle adaptation and go from there. THANKS for the input.
  6. The questions continue (I'm an engineer...) What is there in my manual transmission that would be communicating with the DME? I would guess that disconnecting the battery first in your procedure would erase an existing code? Or, would I expect it to remain? I have been clearing the offending code with my Durametric. I am unsure whether I will be able to duplicate the conditions that caused the failure, on the street. Coincidentally(??), during this same time, I was having trouble getting full power out of the motor. It would not rev past about 5K when floored and would just run out of steam and not go any further. I have noticed some inconsistency with this engine in winding out and getting full power. It has the Vortech supercharger installed and I know that the chip has been modified by the kit mfg, injector rate increased, etc. I suspect a MAF contribution, as a KN filter is installed, so I will clean and/or swap out. Maybe the knock sensor is holding things back. As I said, the performance is inconsistent. Loren, THANKS for your help - always first class service. Darrell
  7. Thanks for the suggestion - but tell me what this is doing and how it relates to the P1508(408). And why would this manifest as a Limp under braking scenario?
  8. "Porsche fault code 408 - Function monitoring Torque comparison Signal implausible" shows up in Engine error codes. Does not throw a CEL. Cleared the error code, and went back out. Happened about 4 more times. Always on hard braking at end of straight, with a blip and downshift. (still not really heavy braking, not going real fast as still learning track). But it seems that engine went to limp before I could blip to downshift. Perhaps went to limp before clutch went in. I was heel-toe'ing on two other corners without incident. (and with less heavy brake) I am wondering if my fat foot is touching the gas pedal during heavy(er) braking prior to clutch-in and blip, and this is when the limp mode starts. Quick turn off and restart and all is fine.
  9. This happened twice to me today on the track, and once over a year ago on the track. During braking and downshift, the car loses power and will not rev past idle. The engine doesn't die. No CEL. Seems like a "limp mode". I pull over, turn it off, and restart, and no problems. I have heard/read somewhere about this happening if brake and gas are pushed at the same time. But, I have also done hard braking and blipping the throttle for downshifts on multiple laps in several sessions. Interesting that this happened at same point on track today - end of straight, braking and downshifting to go into the bus stop at NCM.
  10. The 2000 Millennium Edition was also badged on the rear (and inside door sills) as "911" not "Carrera". ?
  11. The clutch assembly at the front of the compressor has a large bearing in it, which can seize. I don't think Porsche sells the clutch and bearing separately from the compressor, but you may find it in the after market. The pulley still spins freely, so I assume this means that the bearing that would be part of the clutch assembly must still be fine. I cannot get the compressor shaft to rotate. So, apparently the compressor seized, while the clutch was engaged, and instead of the belt slipping, the pulley+clutch unit tore loose the rubber isolator built into the pressure plate hub (the melted rubber in the picture above). The pressure plate hub attaches to the splined shaft of the compressor, and the electromagnet couples the pressure plate hub to the spinning belt driven pulley. So I think I can still drive the car safely with the clutch pressure plate removed, just no AC. Need to figure out why the compressor seized, but bottom line is that I need a new compressor+clutch unit.
  12. Any speculation on the root cause of the compressor failure and seizure? To my knowledge, the system had not been opened up previously and has only 60K miles (but 14 years) on it. I am trying to sort out how much of the system I should change out (receiver/dryer, expansion valve, ...) and other procedures (flushing, etc) to be done. I plan to install the new compressor myself, given the non-standard complexity of the engine compartment with the supercharger install; but will perhaps employ a shop to do the flushing, evacuation, and recharge. I want to pay special attention to getting the correct amount of oil back into the system. The shop manual has some very good and specific references on oil quantities per component and recharging procedures.
  13. Update: finally pulled out the supercharger ducting and found the AC clutch totally fried and the compressor seized. So, I am up for a compressor replacement. The system is still under full pressure. Curious for reasons for the compressor failure. The system had been operating well right up to that point.
  14. Just caught that - I am now a Contributing Member. Best investment. Will scan the document over a beverage this evening. THANKS
  15. "Sorry you don't have permission for that" when I try to download the pdf (will try again at home, perhaps it is my work network that is blocking me) The Climate Control System.pdf is likely what I was looking for to lay out the system, so I can start the search for failure modes. I scanned with Durametric last night, and no codes were present for the HVAC. I have a new set of gauges coming, so I can check the Low and High side pressures. The initial high pressure indication on the Low side told me that the compressor was not performing. Hopefully the Diagnosis guide will help ID the faults before I turn it over to someone else. At a minimum, I will take it to a shop to recover the freon before I start any disassembly and replacement. Thanks for the help.
  16. yes, the condenser fans are running. When I engage the AC, there is no noticeable load on the engine from the compressor, even though the compressor clutch appears to be engaged. It would seem the internals to the compressor are gone, or there is a bypass/relief open.
  17. My AC has stopped functioning. Recently I started the car and engaged the AC and it cooled properly. Parked for a few minutes and restarted (I normally switch off the AC before stopping engine, but failed to do it this time). Upon restart, there was a definite "strained" sound from the engine, my first impression was of a locked up PS pump, that lasted for a bit and then a "pop" or release of some kind and the noise went away. No AC cooling after that. I checked to see if the AC clutch was engaging and it is (and disengages when switched off). I put a gauge on the low press side in the frunk and it showed high pressure. (it was a cheap AC refill gauge that pegged on pressure, so I quickly disconnected for fear of safety. (but I would expect high pressure when the compressor is not running) After hearing the pop and lack of AC cooling I expected to see an obvious release of compressor oil in the engine compartment, but nothing. And I obviously still have a charge of freon in the system. So, the question is where to start diagnosing. It is as if the compressor was pressure locked on the restart, and perhaps there is a relief or bypass that was set. the compressor is hidden under the supercharger and intercooler plumbing, so I will pull that loose to get a better look. 2000 996 C4 Millennium Edition w/ VFEngineering supercharger and assorted other goodies
  18. Very cool. Data is always good. And, doing it yourself, doing it wrong, ... is a great way to learn. I wonder how much the drop links contributed? I have Tarrett adjustable links, but have not tried disconnecting to see if they are preloading or not. Now I am really anxious to find a shop with scales.
  19. Coaster: It would be interesting to see your After numbers on the corner balance. And, what your new ride height numbers are at all four corners. Which corner was adjusted? Also curious of the number of turns required at each adjuster to accomplish the balancing. Are we talking only one or two turns to produce a big change in loadings? I, too, set up my PSS9's to X74 specs (and stayed within the Bilstein TUV limits) for ride height at all four corners. I need to find a shop with scales. Did you set corner balance with or without driver weight in the seat? The shop manual says No. Your before numbers showed 127# bias on the left side. THANKS
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.