P2C4

What is the appropriate minimum RPM for the 996 manual transmission in gears 2 through 6? I assume first gear has no minimum other than the kill factor at about 1k RPM. Does the minimum RPM change for each gear after operating temperature is reached? The reason I asked is that I read somewhere (can't remember where, exactly) that lugging the motor contributes to RMS and IMS leakage and failure. Any truth to that either? Thanks for your replies

For the last 4 years I've had a 1999 C4 as my daily driver. Here's a link to a less than 90 second fix for the problem. Well, the first time you do it, it will probably take you 2 or 3 minutes for the first seat, and half a minute for the other seat. This fix is far less hassle than either a DYI seat belt replacement, or driving some where to have someone replce the belts for you. In four years, I've had to spray the seat belt female contacts and under seat connections I think 3 times. It always cures the problem immediately.

On the Mk I edition of 996 cars (which a 1999 is), you can get a digital temperature reading, and other readings. I learned this from a thread at rennlist. You use the climate control system in the car. Here’s how. Press and hold both the recirculation button, and the top (arrow up) buttons on the right side of the panel for a few seconds. The left screen will change. Pressing the + and - keys below that screen will make the display different numbers from 0 (i.e. zero) to 36, each beside a letter “C”. The reading 6c is the one you want. At 6C, or any other reading, then press the center vent button once. The display will change and show you your coolant temp in centigrade. (The other values possible I’ve not used much.) I just learned of this functionality, and was surprised to see that the coolant temperature may exceed 100 degrees C in slow stop/go traffic. The temperature gauge on the dash at that point reads in or to the right hand edge of the 0 in 180.

Thanks Loren. I looked for something like that, but didn't find it. While I'm asking, is the cylinder number the same for all Porsches or at least all 996 and 997 vehicles?

I have a 1999 C4 with 116K miles. I just changed the spark plugs and coil packs. Durametric software and Check Engine Light codes now tells me I have a periodic misfire in Cylinder #4. I think I know which cylinder that is, but I'd like to be certain. So, as a novice Porsche mechanic I must ask, what is the numbering order of the cylinders? Thanks in advance.

Sorry I ddn't see this post sooner. Nearly 4 years I've driven a 1999 996 C4, daily, year round, in Utah, about 20K miles a year. I put 17" Blizzaks on seperate rims and run those during 5 months of winter. (Summer rims are 18 inch.) Blizzaks are great for snow and ice and my car is better on parking lot ice than my Yukon XL with Goodyear winter tires! Must be the Porsche Stability Management. I take the care up skiing. Everywhere. We had a really bad snow storm in February 2 years ago. A couple feed of snow dumped suddenly. Only me and a Jeep were going anywhere on the I-15, trying to get home from work. I let him go first and followed him through deep snow on shoulders. Porsche is a great winter car. The C4 is definitely needed, as are decent winter tires. The Blizzaks are reasonably quite on clear roads, and feel comfortable at speed, though I've not had them going above 100 mph, and not at that rate often. Normal freeway reach 85 mph daily and the tires are more than fine. Hope that helps.

Loren, what is the procedure to "retrain" the sunroof to its opening and closing positions. Mine in a 1999 C4 stops before the correct end positions, or reaches the closed position and then slides back to 4 inches open. Thanks for your help.

I have a 99 C4, with 78K mi. Daily drive. A couple days ago the brake wear light came on. I had a reputable non-dealer shop check it out and they replaced the front brake pads and sensors. Also did the rear brakes while it was in the shop. They found the front right (passenger side) inside calliper brake pad excessively worn, like it was sticking or being used too much. I've not noticed any pulling while driving or braking. That pad was worn maybe three times as much as the other front pads. I'd done the front brakes about a year ago. They flushed and replaced the brake fluid. That probably hadn't been done for 2.5 years or 40K miles (my bad I guess). I'm wondering if there is something else that I should do to prevent this problem from happening again, or whether further maintenance should be required. Thanks for your thoughts.

99 C4, with 78K mi. Daily drive. replaced water pump at about 41K. RMS leak for the last 20K miles (but I'm waiting for the clutch to need replacement to fix that.) Recently, a sticking caliper on front break, wore one pad badly. Flushed breaks. We'll see if that cures it.

On July 4, 2007, the passenger air bag light came on. That seat gets much less use. I reset the light with the Durametric software (thanks for tipping us on to that Loren), and sprayed the connection under the seat with deoxit5 and the light is back out, likely for another year.

I have a 99 C4 with 55K miles. I randomly read the codes today under the ALARM heading using the Durametic software running on my laptop. It read the following alarm codes: 60 central locking limit position not reached 33 no passenger compartment monitoring 21 no engine start possible 3 door lock barrel open. The number of times DTC present for each code as 4 for Code#60, 3 for Code #3 and 1 for the other two. I've not noticed any miss behavior of the vehicle or its locking mechanism, other than sometimes the car might not lock or unlock by remote key when I'm out of range. I've searched this site and found noting about alarm codes, or alarm or faults, or alarm and any of those specific numbers. Any ideas about what this means, and what if anything I can or should do about it? I don't seem to be able to re-set these codes with the Durametric software. Is there a way to reset the codes? Thanks in advance for your replies.

1999 C4, 54,000 miles. Water pump at 44K, and the driver's window up/down feature 40, one bad line on the rear defrost. A great car. I think Porsche makes great cars if you treat them right. I owned a 1986 944 for 12 years and sold it at 202K miles, after a clutch and some rad reparis along the way. My perception, totally subjective, is that it ultimately costs less to maintain a Porsche than what Detroit produces if you keep both for 150K to 200K miles.

I just thought I'd add that both seats have so far remained fixed. I drive the car every day (18K mi/year).

After a little more than 6 weeks my airbag light came on -- fault code 45 drivers seat belt. I use my car alot, and the driver buckle probably had about 150 connections and 150 unconnections in that time. I think the light came on when the seat was adjusted -- rolled backward-- more than usual to accommodate the long legs of my son. That may have pulled on the wire connections under the seat from the seat belt. That's my theory. I sprayed the buckle with DeOxit5, and that didn't keep the light from coming back on. So for the first time ever, I sprayed the connections under the driver's seat. You may recall from my above post that initially I only sprayed the wire connections under the passenger seat belt. And I must apologize. It was more difficult to get at the connection under the driver's seat because apparently it has a little plastic guard at the front of the seat near the carpet. My passenger seat is missing that part. The guard had to be pulled forward to be rmove so I could see and spray the seat belt wire connections under the seat. It took me 10 minutes and a mirror to figure out how to pull that guard off. Getting it back on was easy. Spraying to 20 seconds. The airbag light has now been off for 9 days with my continued heavy use of the car. I still need to spray all the connections with ProGold.

I didn't remove the seat. I just gave each buckle a pretty good shot around the insides edges (with a rag rapped around the outside of the buckle to catch any over spray), and under the seat passenger seat a good shoot into each wire entry position in the plastic junction box (about two inches square) where the wires from the belt buckle lead. Don't forget to attach the little red tube to the spray can.

I think Kim's right. It might be a temporary fix. But if it's like audio equipment, you simply re fix it. And then preserve it (which I haven't done yet) with the DeoxIT Gold G5. I've got a can, but haven't used it yet (still pursuing the experiment). Some audio high end equipment employe gold plated connectors on input/output jacks. They still benefit (a little) from a regular annual cleaning. We're a little more than 3 weeks into my fix now with no problems. And the fix took about 30 seconds, or maybe 2 minutes if you count resetting the codes. So, if buckle replacement takes 2 or 3 hours . . . well, I think I could fix this pretty often and be time and money ahead. As I read this message board it seems Loren is almost never wrong. Let's hope this one surprises him. I'll update this post if this fix ever unfixes.

I have a 1999 C4 which I purchased 4 months ago with 37K miles. Ever since I've had the car the airbag light has been on. I read many threads on this site about the airbag light and what it means, including the technical bulletins. (Thanks Loren.). The local dealership wanted $600 minimum to fix the problem. Here's the odyssey. A couple months ago I bought the Durametric software and cable and used it to read and reset the error codes or fault codes and had numbers 45, 46, 47 and 48 which relate to the airbag light and the seat belts on both the driver and passenger sides. The message associated with the numbers was drive or passenger side "belt buckle may have been unplugged at some time, check connector to belt recepticle." So, I reset them. And they'd come back, particularly the passenger side. They'd come back on randomly within minutes or a few hours of a reset. So I prepared to purchase new seat belt buckles. Then I had :lightbulb: an idea. I didn't recall reading any thread here about cleaning the contacts. So, I sprayed both belt buckle recepticles liberally with DeoxIT D5 (using the small red tube to direct the spray), and I elevated only the passenger seat and sprayed all the electrical junctions I could find where wires from the seat belt connected. I'm used to being fussy about electrical contact cleaning for improved sound in my stereo and home theater system (yes it really does make a difference, and yes sometimes you can hear a difference, particularly in the high frequency sounds). Well it seems to have worked. It's been 3 weeks now. No airbag fault codes. I drive my C4 every day, usually 80 miles or so. My daughter is working with me this summer, so between us we operate each buck at least half a dozen times a day. And we've had no problems. (Knock on wood.) A word of caution. DeoxIT D5 is highly flammable, and the stuff will ruin the finish. (Keep a wet rag around to wipe off any over spray.) The spray nozzle on the 5 oz can be adjust to three positions. I used the lowest setting. This stuff will also clean up noisy switches in radios and other electronics. Usually it works best if you spray it on and then let things sit for 5 minutes, and then wipe off the contact, and then treat it with DeoxIT Gold. I didn't wipe any off, and I haven't treated my seat belts with any contact preservative (yet). :unsure: I hope I'm not just temporarily lucky, and I hope this helps someone else.

Thanks. Well, reduction of heat is what I'd really like to achieve, if possible. Any added power would be a bonus, not a goal of this project.

Motorcycles use exaust wrap tape to increase performance and control heat. I've not used it on any of my Porsches. But, like the above post, I'm interest in whether anyone has tried exhaust wrap tape, and what their take on it was. Did it increase performance? How much cooler was the engine compartment? Was it worth it?

You may be right. But I had a rear wiper on a 944 that I drove daily for 12 years. I used it, and liked it. Ugly? Maybe, but definitely functional. My C4 is now my daily drive vehicle, and I'm serious about putting on one. Has anyone retrofitted one?

Has anyone added a rear wiper as a DIY, or through a dealer? I'm interested in how it turned out, and what it cost if done through your dealer. Thanks.

Thanks.

bump

For a month I've owned a 1999 C4 with 39K miles. (It replaced a 1986 944 I'd enjoyed for 12 years.) I tried out the headlight washers a week ago, and it worked fine for the first two sprays of washer fluid. Then nothing, except leaking washer fluid from the left front wheel well close to the door, as others described above. The washer fluid light came on. Filling the tank again immediately resulted in more leaking from the same place. So, tonight I took off the wheel and wheel well liner. I couldn't get the washer fluid tank out. It appears to have some kind of a snap in plastic plug integral to the tank running horizontal toward the door. Anyway, the pump for the headlight washing system is behind the tank. I pushed down on it since it seemed to be separated in the middle (or from one black part to another of the same more than an inch diameter), and that solved the leaking. The tank now holds water, and the windshield washer system works fine. But the headlight washersystem doesn't squirt water. It makes noise like its trying to pump, but no water sprays on the headlights despite repeated trys. All hoses appear to be connected. Is my headlight washer pump burned out? What do I do to get the headlight washer system working? Thanks in advance for your comments, and for the many past comments. This is a great site. :D