996noob

That is what they termed surface-air gap, whereby the carbon or soot buildup on the insulator allows the spark to jump along the conductive deposits and then the the air gap to the electrode, effectively a self-cleaning feature. However, I believe this exists for any spark plug, not just the Bosch ones. As long as there is an electrode, there are two ways it can spark, the air gap, or the surface-air gap. For a single electrode plug - there are two ways, 2 electrode - 4 ways, and the 4 electrode - 8 ways. It's just that with 4 electrodes, the rate of widening of the gap is slower as it is shared by multiple electrodes, and this is the main USP of the Bosch 4 electrode spark plug.

Back when I worked for Bosch in the South East Asia region, the marketing emphasis for the Super 4 was not so much any added performance, but rather that having 4 electrodes meant that the prescribed gaps would widen 4 times slower than single electrode plugs, and 2 times slower than double electrode plugs, resulting in longer service life than conventional plugs - it was as simple as that. During product training we would also emphasize that only one of the gaps fired at any one time, not all 4, and that it would be random, whichever air gap that would jump easiest at the particular time. I think consumers may have made assumptions about the product that were never intended.

I used to work for Bosch (diagnostics sales) but was always told that we couldn't get the Porsche software for our KTS machines to convert them to PIWIS. I guess that's what they told us to keep us from checking further. Anyway, it's been some time since I left the company, but I could get still get a KTS if I contacted them. When I left, the newest model was the 650. What's the model to get now if you wanted to convert it to a PIWIS? And where would you go to get the software to convert to PIWIS? You could PM me if you don't want to reply on the forum. Thanks! Any update on your wireless solution?

Recently, my light switch jammed up and could not turn off. I had to force it off by using force, and in the end I lost the "indexing" of my light switch. I think the "indexing" parts internally broke apart. Is the part the same for all 996 model years? Is it expensive?

Thanks...I'll check the bushing and see. Sounds like everyone's experience is pretty touch so just might have to lever it in. Any other tips would be appreciated. I also gave in last night and had it towed to the shop but determined to finish off the job and get her back on the road. Darron I am pretty certain that your bushing is not retracted enough. If it took some effort to remove, it will take even more effort to re-install. I had the same problem, and could not for the life of me get it pressed back far enough with the tools I had at home. You could fashion some sort of "puller" from bolts/nuts/spacers, but I think sending the alternator to machine shop that can press things in and out would be the easiest option.

I have tried that exact combination and can attest 100% that it will fit. Those widths and offsets are very common for aftermarket "Porsche" replica wheels, and are actually a 997 width and offset combination. However, I have found that on the 996, looks-wise, the fronts are a tad too far into the fenders in relation to the rear which are just about right. While the wheels will fit, they are quite far off spec from what Porsche recommends for 996's, just for your information.

Did you need to run a relay for the higher current draw of the more powerful horn? Or did the supply of one side of the original horns have enough juice?

Theoretically, the Y connector should be connected to 3 things which are; vacuum reservoir, switchover valve, vacuum source. Since you have traced the connections of the Y connector to the first two mentioned, then what you are probably missing is the vacuum line to the vacuum source at the left or right rubber sleeves which connect the air intake T-piece after the throttle to the left or right intake manifolds. Somewhere along this vacuum line, you should also have a one-way check valve. From memory, I believe you need to take out the throttle body and all that stuff to get access to the Y connector behind it. Your engine will not run well without the vacuum line connected. 1) you will have a vacuum leak. 2) your reserevoir will not get a vacuum accumulated 3) your resonance flap will not move. Hope this helps.

Headers, Cats, and Tips look standard to me. Only the Mufflers look to be changed.

I agree. The bolt pattern on the exhuast gasket and mounting flange is totally different.

HI, Its looks like I have a leak similar to this. Does anyone have any experience of changing the tensioner seal. How do you lock the cams? What tooling is needed thanks Jetbox Me too, I have a leak at the big nut as well. Would be helpful to know what is involved in changing the seal (is it an aluminium crush washer?).

Was the airbag from the new dash different? Or did the seller not provide the new airbag, and you used the existing one? Reason that I am asking is that I have the opportunity of getting a Mk2 dash with the glovebox for my Mk1, but on the "new" dash the airbag has been activated. So I was wondering if I need it in the first place, and if I can use my existing one.

I did a search on this topic and found this thread http://www.renntech...._1entry160676 I'm moving over my discussion to that thread.

I have the opportunity to get a Mk2 dashboard from a C4S, and would like to install this, if possible, into my Mk1 (1999 C2). The objective really is to get the glove compartment of the Mk2, while getting an overall better condition dashboard in the process. Here are some technical hurdles I might need some help on: The C4S airbag has activated. Can I use my Mk1 airbag unit and also the cover? Are the dashboards interchangeable at all? Are the electronics, if any specific to the dashboard, interchangeable? Is the instruments cluster the same? Have I overlooked anything?

I've researched this and have determined that the bolt pattern on the GT3 header to engine flange is totally different from the 3.4/3.6 engine of the 996 C2/C4/C4S. They won't fit. However, the mufflers MAY fit, but I am still trying to find conclusive evidence whether they do or do not.

so that vacuum switch activated the resonance flap on the intake? That looks like the switchover valve for the intake flap. You should have two hard vacuum lines connected to it, one from the vacuum tank buried behind and under the intake, and the other line goes to the flap. The lines are extremely brittle on old cars. I had to change mine as they just desintegrated when I tried to handle them.

I was unaware that Porsche made a 996 emblem in the size of the GT3 emblem, for the rear of a 996. Is it Chrome or Black, or come in both colors? What is the part number? I like the idea of 996 on the back. Never seen it.

You were right!

After taking the car back from the paint shop, I realized that the Litronic dipped (main) beams won't angle up when I flash the high beams. Could this have resulted from starting the car with the lights removed? I would guess that the painters might have moved the car while the lights were not installed. How do I diagnose and solve this problem? My car is a 1999 996 3.4L Coupe.

Should've said so earlier! Sending you a PM now.

While I agree with you that I'll probably be running them on loud mode most of the time, I need the switch for inspection purposes (inspection is annual) and when our "department of transport" cops come alongside the car (they'll stop you and give you a hefty fine). I'm lining up a set of used PSE's very soon, without the vacuum or electrical circuits, so this write up is very appropriate for me. Looks like I will not need to use a dedicated vacuum tank, as I suspected. I have made up a list of parts based on the relevant TSB's for the install of PSE. However, I can't figure out why there are several different numbers for the harness, or is it that these part numbers are for a set of parts including the harness? 928 573 727 03 Y vacuum connector x2 928 574 717 03 L vacuum connector x4 917 355 021 00 SS Braided teflon vacuum hose (L=380mm) x2 999 512 069 02 Clamps for braided hoses x4 996 605 123 01 Switchover Valve 996 613 987 10 Switch (Right Side of Radio) 996 613 988 10 Switch (Left Side of Radio) - "Tekalan" Vacuum lines Harness numbers: 996 612 978 00 PSE electrical Harness, but may include Relay and Switchover valve? or 996 612 980 03 PSE Harness? or Relay? or Both? I'm confused by the last two part numbers, and possibly by ordering them I may not need to order some of the above parts as they may come with. Unknown part numbers: Bracket for Switchover Valve Any advice on the part numbers?

Orient, thanks for the link to your write up. I'm going to go through it right now. Can I PM you if I have any questions? I'll post a summary of my understanding here so that we have something on Renntech for future reference.

While I agree with you that I'll probably be running them on loud mode most of the time, I need the switch for inspection purposes (inspection is annual) and when our "department of transport" cops come alongside the car (they'll stop you and give you a hefty fine).

I've been reading and re-reading the TSB for the installation of the PSE for 996 so that I can try to fully understand what's going on. I'm learning abit more each time I read it. My understanding is, for the 996, only the speed signal is taken from the DME, to switch the PSE off and on at some speed range, this feature I do not require, otherwise, the switch itself is connected to a relay, and relay connected to the switchover valve, via the harness. At this point, I am inclined to think that I should be able to run the circuit without the additional vacuum tank that comes with the PSE kit. Just wondering if anyone has DIY'ed the full PSE kit with switch on the 996, and perhaps help me understand better how it is wired. I know that quite a few here run the mufflers without the other parts, though.

Yes, many have. Do a search here for detailed descriptions. No wiring in the harness unless your car was ordered with PSE. Only one wire needs to be run from the engine to the dash. Or, some folks do not use the switch as the PSE default to always open (loud). Yes, in the TSBs for Carrera 996. Yes, you take the tips off your old mufflers and put them on the new PSE mufflers. Not usually. The switch is sold seperately but otherwise everything you need comes in the PSE kit. (again see the TSB for a list of parts) If I managed to find used PSE mufflers and wanted to install the switch, what parts would I need to get in order to control the switchover valve? I could follow the TSB and parts list to the letter, but is the there a short-cut circuit I could rig up with just the original switch and a relay and some wiring? I don't need all the functions of the speed range switching, etc.. I was wondering if the job could be done by getting the PSE switch, harness + relay (996 618 980 03) and switchover valve (996 605 123 01), some vacuum tubes and accessories, and tap the vacuum from the existing canister line, and control the PSE with that. Any advice?