Richard Hamilton

Mark I had the same wind noise on mine, and found that it was because the window was not going high enough. This caused the top edge to get sucked outwards at speeds above about 85mph, and break the seal at the top. Adjusting the door strike plate was absolutely the wrong thing to do, and I would question that with your dealer. There is a procedure in the manual for adjusting the pressing force of the window against the seals, which is pretty much as PTEC describes. There is also a procedure for adjusting the door window height, and angle in the longitudinal direction. If you want, I could email you the pages of the manual. PM or email me with your email address if you want them.

FWIW - The DME diagnostic section of the manual shows the Mass Air Flow should be 17kg/hr +/- 2.5 14500/3600=4.02 g/sec 17000/3600=4.72 g/sec 19500/3600=5.41 g/sec 5.34 is definitely not low, and appears to be within tolerance. Loren, thanks for the drawing of the EVAP canister purge valve - you had sent it to me before. I assume it is attached to the inlet manifold, but before I start delving into it, does anyone know what it looks like, and is it serviceable? A photo would be wonderful. Tool Pants seems to have a photo of every component on his Boxster - how about this one?

I have still got the P1123 & P1125 error codes on mine, but NO CEL. Checked fuel pressure - perfect. I would check the EVAP canister purge valve if I knew where the heck to find it. I have just tried a bottle of injector cleaner in the fuel tank, in the vague hope that this will cure it. I'll let you know if it works for me. Meantime, anyone know where the EVAP canister purge valve is located (inlet manifold perhaps), and what it looks like?

I don't believe they have redesigned it - that's the problem!!!

Thanks PV. My last question (I hope!): I know the #009 connector pins go into the instrument cluster plug, and the #010 leads go into the cruise connector, but do I need #009 or #010 leads on the Motronic plug? I know that the pin on the end of the #010 lead is part number 999 652 901 22, but what is the part number of the pin on the #090 lead? Hopefully our OBC guru (Tool Pants) has the answer :king:

2001 C4 Cab - Uk spec. I am just trying to get things straight in my mind before attempting this, and have a couple of questions: 1) If the clutch switch is in place and connected, I assume there is nothing more to do with it. Correct? 2) Are the pin connectors the same on the cruise stalk connector as on the motronic plug? (999 652 901 22). As far as I can see, there are just 5 wires to connect: Cruise connector Pin #1 to Motronic Connector #IV pin 27 Cruise connector Pin #2 to Fuse B7 Cruise connector Pin #3 to Motronic Connector #IV pin 25 Cruise connector Pin #4 to Motronic Connector #IV pin 19 Instrument Cluster Plug 1 (blue) pin 16 to Motronic Connector #IV pin 18 And activate it with the PST2, of course. Is it really that simple? :(

Sorry, it's a regular C4 Cab - wishful thinking on my friend's part!

Thanks Jeff It is a friend of mine who is interested in doing the retrofit on his C4S. I don't think it is a practical proposition to do it on my 98 C2. It seems like the C4S should be fairly straightforward provided stuff like the clutch switch is fitted. We need to start crawling under the dash. If anyone has actually done it on a 996 it would be useful to hear from them - especially if it was a RoW model. P. Viby perhaps? Jeff or Loren - Is the Motronic version the same on a C4S as an egas Boxster? (I think it is 7.8 on the later 986 Boxsters). Unfortunately I don't have the wiring diagrams for the later cars - unless anyone can oblige?

Is the cruise retrofit fairly straightforward then? I have seen the Boxster retrofit instructions - any pointers for the 996 anyone?

This is a UK specification 3.4 litre pre-facelift 2001 model C4S cabriolet. Does it have fly-by-wire throttle, and hence is cruise control retro-fittable?

There must be some region-specific coding in the instrument display, to account for the difference between UK/US gallons. Even my '98 996 is user-switchable between Metric/Imperial - not just on the OBC, but the digital speedo as well. However, you have to connect the PST2 to change the temperature display on the aircon.

The most likely difference between the 996 and GT3 gearboxes would be the ratios used. It might be that the synchro rings and hubs could be the same. I know that Porsche have a similar policy on the tiptronic boxes - replace the whole box - but you can get the parts from ZF suppliers. Perhaps when the box ends its production run (I assume that the 997 uses the same box) the parts will miraculously become available.

Is the GT3 gearbox the same basic unit as the 996? If you look at the PET you will see that all the gearbox parts are listed separately, and most have 996 part numbers. It might be worth looking in to.

I wonder if it could be a differential problem. Do you feel or hear any rear tyre scrub in slow speed tight turns?

Mine is definitely 10mm hex, which is the ISO standard for M6 thread. 13mm is the standard hex head on M8 screws. Either mine is unusual (maybe it has been replaced with an ISO standard screw) or Mr Porsche, in his infinite wisdom, chose a special screw for this application.

Just to get really picky, the DIY shows the M6 screw as needing a 13mm wrench - in fact, it should be a 10mm wrench. Sad, aren't I?

Thanks Jeff I guess I should stop worrying until it starts to run rough. Can you tell me what the EVAP canister purge valve is?

I had this on mine, and it was the anti-roll bar drop links. (Maybe you call it the stabiliser bar). The joints on one end had worn, causing the clonking sound. "Cheap" and easy to fix - less than $100 for the parts.

Maybe I should try this as a new post. My DME fault register shows P1123 and P1125 fault codes, but I DO NOT get the CEL coming on at all. The car runs fine, but I would like to find out what is wrong sooner, rather than later. The DME actual values I am reading are: Idle Speed - 680rpm Load Signal - 1.3ms Mass Air Flow - 19 kg/hr Hot film mass air flow meter - 1.31 volts Engine Temperature - 90°C Throttle Plate Angle - 0° Ignition Timing - 5.3° crank Specific Air Mass - 17.0 kg/hr Specific Air Adaption - 3.0kg/hr Injection Time - 2.8ms Oil Temperature - 90°C IATS - 27°C ECTS - 92.3°C Oxygen Sensing Cyls 1-3 - 0.9 to 1.0 (varying) Oxygen Sensing Cyls 4-6 - 1.0 to 1.15 (varying) Range cylinder 1-3 (FRA) - 1.02 Range cylinder 4-6 (FRA2) - 1.01 Range cylinder 1-3 (TRA) - -0.36 Range cylinder 4-6 (TRA2) - -0.33 O2 sensor ahead of cat conv (1-3) - 0.1 to 0.7 volts (varying) O2 sensor ahead of cat conv (4-6) - 0.1 to 0.7 volts (varying) Camshaft Position deviation - -3.0° crank Rough running threshold - 8.4 Rough running - 0.0 Segment (A) - 1.0 Segment (B) - 1.0 This should be Segment B - I can't get rid of the smiley! Learning progress, sensor wheel adaption - 0.000 Misfire detection - 0.000 Engine compartment temperature - 60.0°C Oxygen sensor heat resistance ahead of cat conv - 3.2ohms I have checked the fuel pressure, and it is spot on - 3.8 bar engine off, and 3.3 bar at idle. I think all the readings are within the range of nominal values in the manual, except the TRA values that are way out. "TRA - Time Relative Adaptation; a fuel injection adaptation method used to compensate for engine/sensor changes at idle, which are short term & small affecting the AFR, e.g. intake air leaks, and which generally varies equally with +/-values under normal conditions (taken from www.systemsc.com/glossary.htm)". I don't think it is an air leak, because the idle speed and mass air flow are within limits. The MAF sensor readings also seem to be correct, and I think the FRA values being correct bear this out. Any ideas anyone?, and BTW what is the EVAP canister purge valve mentioned in other similar posts? Sorry for the amount of data, but I thought that too much was better than too little. I'm not sure what all these readings mean - I just took them straight off the PST2.

Berny By taking the oil filler cap off you will have introduced an air leak and the ECU will richen the mixture accordingly, hence the rough running. Small leaks, like a leaking cap, can cause the idle speed to raise 3-400 rpm, and again it adversly affects the mixture control. If you have a scanner, plug it in and check the idle speed (should be 680 rpm), and also see if you have error codes. Richard

Sorry to butt in here, but I have a similar problem on my 1998 C2 tiptronic. My fault register shows P1123 and P1125 fault codes, but I DO NOT get the CEL coming on at all. Ignore this - I started a new thread.

I agree with Loren that the third party manuals aren't very good, and the bootleg Porsche manuals are pretty poor quality usually. However, this week I bought one on eBay made by LexCom Informationssysteme GmbH in Germany, which seems to have been made for Porsche, or with their approval, perhaps. It is a properly indexed and bookmarked pdf copy of the factory manuals, and covers 1998-2001 models. If you see one of these, go for it - it's the real deal.

Yes - thanks for that Loren - extremely useful!

1qt/1000 miles seems like a lot to me. I change my oil every 6000 miles, and don't need any top-ups between changes. Mine is a 60,000 miler. Piston ring wear could be one cause, but it could also be valve guide wear. If you get a cylinder leakage test done, it would determine if it is one or the other (or both).

Thank you for all the information Jeff. I ordered the wires from my local VW dealer and they should be in today. They were readily available from VAG UK. Maybe all us Porsche guys buying these leads are causing the factory to remanufacture them! ps. I should be able to email you the pictures we discussed on Thursday.