JFP in PA

You tech is pretty much correct; these lines were never meant to be serviced with the car assembled, so there is quite a bit of work involved.

Welcome to RennTech :welcome: Glad we were able to help you on your quest to find a Porsche. Now might be a good time to consider becoming a contributing member, which would give you even more access the our library of technical information.

Amazon.com carries some of the LN Engineering parts, so that might be a good starting point. I would also "Google" your location, you may find someone nearby as well.

UPDATE & reply to JFP with a finished C4S (YAY): Well I have my 2004 C4S back with a working & very strong Tiptronic Transmission. The replacement Tipronic S sent by LA Dismantlers was received, installed, re-coded & adapted uneventfully. While this was a very time and $$$ consuming experience, and JFP the sole responder, I still owe JFP & Renntech an update. Mainly in case anyone else picks up this thread looking for Tiptronic S replacement info or data regarding LA Dismantlers / LA Porsche. Turns out my wrenches at Autobahn in Copley, OHIO knew exactly what they were doing. Louie Pejnovik, owner and brother John were exceedingly patient and professional throughout this process. (both with me and LAD) Their mechanics clearly are 1st rate. I mentioned in a previous post that mucho time was spent trying things with the 1st Tipronic S sent by LA Dismantlers (LAD). Todd Dakarman of LAD even sent another TCU to try. I think he thought Autobahn was not competent. I'm sure he runs across that from time to time. Well they are competent Porsche certified wrenches with all the right stuff. Autobahn also tried switched out the conductor plate, valve body and harness. All to no avail. That extra work trying to get the bad LAD tranny to work cost a great deal of $$ given multiple re-adaptaions and driving tests. Nearly $1500. So how did it end up? After about 750 miles of fairly hard driving to make sure all is well, all is well. I have my C4S cab back with a strong Tiptronic S tranny and all is well with the world for now. Not any spec of oil leak anywhere. I let LAD know and they arranged to have both my original core and the bad tranny picked up. Upon arrival at LAD I knew I would get my $1000 core charge back, but anything else? I know the "warranty" on used parts is part only but anything else? It seemed LAD may be aware of my posts here and on Rennlist, but I'm not sure. While initial response about the 1st bad tranny sent was slow, EVERY contact was very professional and EVERYthing they said they would do was done. I dealt with Caleb mostly, but also with Peter & owner Todd Dakarman. I carefully and politely spelled out all my costs. Autobahn agreed to split my costs into 3 invoices 1) Original R&I with some other work I had done since the drive train was out of the chassis. 2) Labor & parts attempting to get the bad 1st Tiptronic S to work. (We went thru a lot of Porsche ATF & filters LOL) 3) The final R&I for replacement Tiptronic S #2. I received an immediate response that Todd was reviewing. Within 24 hours Caleb advised me they would refund my $1000 core charge + $1500 for all the extra work AUTOBAHN did trying to get the first transmission going. $2500 - nice. Furthermore I was offered $1200 store credit or $600 cash for the 2nd R&I. I felt that to be very reasonable given the fact they did not have to anything, if they wanted to be the "bad guys" some portray them to be. So did it still cost me way more $$ and time than it should have? Yes, but stuff happens. I drew the short straw in that respect, but LA Dismantlers made it hurt less. It could have been much worse, if it wasn't for their thoughtful professional response to the problem. As a professional myself I've always been a believer that no matter how capable you may be, stuff does go wrong. What separates the pro's from wannabe's is how they respond to a problem when it does happen. Ultimately LA Dismantlers stepped up and handled the problem very professionally. By this measure LA Dismantlers is top notch IMHO. I have my beautiful 996 C4S back and feeling good again. Do I wish it had round headlights? Sometimes LOL. But this C4S is still a super car with an original window sticker of $109,000, and more car & more fun than most people will ever experience. It also helps that I got a smoking deal on it when I purchacesd it this spring. Now I have close to a retail price into the unit, but that's OK. I love the car. If you may be wondering why someone would go thru this for a lowly '04 996 - this pic and the driving experience says it all. over & out. - Hutch Carrera 4S-5c.jpg :thumbup: Glad to hear it all worked out for you. Now go drive it like you stole it!

We have a lot of customers running the magnetic plug, which is a good idea. I also like the spin on filter (100% filtration) and a FilterMag as well.

I wouldn't use that oil. Look instead at Joe Gibbs DT 40, a very high ZDDP 5W-40 oil and plan on 3-4K between changes..

Yes, it can be done, but it is a bit of work. You will need to locate the later parts and then make up a wiring harness to connect into the car and run it to both ends of the car to connect to the latch mechanisms. Because of the effort involved, the view may not be worth the climb.

If the car has been sitting, it might be a temporary thing. Problem is that you need to get the car into running and driving condition to find out. Also, please do not duplicate post, it is against forum rules. I have removed you second posting of this.

There are a lot of iron and steel components in these engines; valve springs, cams, crank, etc. It could be from any of them. I would plan on shortening your oil change cycles to monitor this, and running oil with as high ZDDP level as you can find.

Do a search, this is a common failure that occurred on early 986's. You have probably snapped the plastic ball bits on the top mechanism and need to replace them. Been written up multiple times.

It always helps to have the year and model of the car. If the clutch slips at all, it is not normal behavior. Does your clutch pedal seem high and unusually stiff? 2004 911 C4S No, clutch seems normal to me. Well, it you are seeing slippage, there is something seriously wrong that is probably not going to heal itself. If the clutch is not something you can deal with yourself, take the car to someone that can.

Hey JFP,, The failure lights show up at highway speeds and not during braking, which led me to believe the problem is probably not inside the braking system. That's why I was thinking MAF or speed sensors. Does that make sense? Perhaps, but even voltage spikes can trigger these MIL's, which is why you need a Porsche specific scan tool like the Durametric system to read the codes to see what is going on.

The brake hydraulic system may just need a complete flush, which if you are getting ABS/PSM faults, the Durametric system can help correctly activate during bleed process.

Sorry, but I would never do this in that manner, bouncing an engine off the rev limiter while standing still is a recipe for disaster. You need a system that logs (read records) the data over time, and then drive the car and collect the data in a "real world" (read engine under load, not free wheeling) manner; then you take the car out for a brief run, let it record the data, and review it afterwards. With a decent system, like the Durametric, you can collect data from multiple system simultaneously so you see the systems interacting.

Yes, at WOT the engine is inhaling all the air it can get, and the fuel system has to deliver enough fuel to keep it happy, if it does not, the engine leans out and starts to miss. I would also look at the MAF values both at idle, part throttle and WOT.

If the system can record fuel trim data, try making a pass in the car with it recording and then look to see if the fuel trims drop off lean when the misfire occurs. if it does, the car is basically running out of gas at high revs, which would probably be a fuel delivery issue (pump, pressure regulator).

While the crank position sensor might not code, the car would not even start if it was bad. The cam sensors would throw codes. I would still suggest checking fuel pressure and delivery just to be on the safe side. If you could get access to the Durametric software on a laptop, you could record real time data while actually driving the car, which could throw some more light on what exactly is happening when the car starts to miss, including the fuel trims.

Welcome to RennTech :welcome: OK, let's start with a couple of "obvious" places to start: How old are the coil packs and have you checked them all to make sure the connectors are properly seated? If the shop that worked on the car was dense enough to not torque the plugs, you can pretty much bet they did not properly check the coil connections. Look at the coil packs and check them for signs of cracking, while completely normal, it a sign they are getting old and need to be replaced. If the car was in my shop, I would be bore scoping the cylinder where the plug electrodes were missing as they had to go somewhere. Same thing applies to the current cylinders that are misfiring. I would also be running a compression test at a minimum, preferably a leak down on the same cylinders, just to make sure these is nothing physically wrong with them. I would also be checking the fuel pressure and delivery rate, just to be sure that the system is not leaning out at higher revs. When was the last time the fuel filter was changed?

It always helps to have the year and model of the car. If the clutch slips at all, it is not normal behavior. Does your clutch pedal seem high and unusually stiff?

I'm not a big fan of swapping parts out without knowing why; I prefer to do one at a time, particularly when parts like that bleeder valve retail for nearly $100. But I have the benefit of a shop with spare parts about for most things. That said, it would depend upon how much the extra parts cost, and how much you value your time (not having to address the same problem twice).

Correct, but most DIY'ers really cannot justify the nearly $1K price for a smoke generator, which leaves them the "hands on" approach.

Depends on which side of the valve vacuum is being applied. Normally, when these fail, they are either stuck open, stuck closed, or won't hold vacuum.

This is one for the Boxster, but the basic components are pretty much the same:

Yes, plus others scattered around the system.

That would be a good starting point, but I would also look at all the flex lines as we often find small cracks in them as well.