Dale_K

Do you have a low temp thermostat? This is totally a guess but something like that might confuse the computer for stuff like whether the car has completed a full driving cycle.

I had my passenger seat out and that looks like the decorative cover that fits on the front side of the seat rail bases.

I don't know how to jump the resistor but you can turn them on in high or low with the Durametric software. Otherwise I guess you could see if both fans work in high speed when the coolant gets really hot. If both fans run in high but only one in low I guess it would be the resistor. If one fan never runs and the other runs in both high and low may be you've got a bad fan or bad connection to the fan. I think the resistor is out of the picture in high speed.

What year is the car? Does it have a Tiptronic? My car has a Tip and there is a vacuum operated coolant control valve that can create a vacuum leak if the valve is bad but only in high temp situations, when the car thinks the Tip needs more cooling. I think vapor lock is less of a problem on cars with the pump inside the tank but I guess you could have a faulty fuel pump or fuel pressure regulator. You could buy a fuel pressure testing gauge and compare readings before and after the motor heats up. Different year cars have different fuel systems (two pipe, one pipe).

No gasket on mine. I first replaced my cap and bleeder valve and only did the o-rings when I still had a leak. Actually I think my bleeder valve is OK because the new and the old felt the same. And the cap should have a part number that ends in the suffix 04 if you want to be sure you have the latest version. Basically I don't think you have a temp problem but instead a leak problem. Put on a new cap and bleeder and see what happens. I've been seeing temps near 100 and I did for the first time see 3 drops of coolant on the garage floor this morning. I guess the hardware store o-rings aren't sealing perfectly. They certainly aren't metric o-rings. Let me know if you want my old bleeder valve for free.

Not speaking to the issue of temps, but I was able to fix a leak that caused coolant to be released near the right rear wheel. There are 2 o-rings under the bleeder valve housing. I matched some up at the local hardware store for less than a dollar. After you take out the 8 little bolts and remove the bleeder valve cap the remaining piece actually lifts straight out but it is likely to be kind of stuck so you need to grab it with some big pliers and wiggle it a little. The o-rings loose their shape over time and won't seal. Here's a couple pics I took. This is the part you have to lift off with some prying. The o-rings laying loose.

This is totally a guess, but maybe the fuel pump? Try opening the front trunk when the sound is active. I'm having some squealing sound when the motor compartment gets heat soaked so I sympathize.

I read a post somewhere about one of the large independent Porsche specialist who can reprogram the DME to completely ignore the immobilizer. I don't know if that's actually your problem because I'm not an expert here but just a thought since you've not gotten to the bottom of it yet. I guess you've already tried different keys.

Another possibility is the o-rings under the bleeder valve are leaking. I assume they transferred the bleeder valve from the other tank. On my car leaking o-rings will allow the coolant to exit by the right rear tire and not into the trunk. Here's a picture of the o-rings. The other poster could well be right that air in the system is making the car overheat.

I've noticed something similar on my 2000 S Tiptronic but later I realized I needed to press even harder on the gas pedal. I think there is a switch that detects a request for full throttle. I just walked out to the garage and checked this. In my car I can definitely feel a click at the very bottom of pedal travel when I press it with my hand. It's surprisingly stiff. A person could think they had their foot all the way down when it's not.

I noticed a pattern with mine. If I start the car and move it a few feet, then wash it and start it again to move it back in the garage, it will very reliably smoke pretty bad the next time I start it. Otherwise it doesn't seem to smoke and doesn't use oil between changes.

Maybe you could check the fuel pressure. That's only a guess on my part.

This is just a guess but maybe your oil fill tube was already old and working around it may have damaged the accordian section near the rear buckhead. You could try wiggling it with the engine running to see if you can hear anything or notice the motor changing its rpm. Or you could spray some flamable solvent (carefully - fire extinguisher on hand) on the fittings around the area to see if the motor picks up speed to pinpoint a vaccum leak. Some garages have a special smoke testing machine to locate leaks.

I replaced the "vent valve" on my 2000 S and did it wrong the first time resulting in a situation where I couldn't get any gas in the tank. In my case I didn't put the trigger unit in correctly. It's a piece about the size of a pencil with a small wiring harness connector. This is my old vent valve. Actually I don't think there was anything wrong with the original but I broke it taking it off. It only cost about $35. A picture of the trigger unit. A new one comes with the valve. The trigger unit fits into a recess in the vent valve, right against the fill tube. I don't know for sure but I think it must be a magnetic switch. If you push the little tab on the vent valve with a small screwdriver (visible at the edge of the filler pipe surround) the car will accept gas slowly even if the venting system is messed up. I had to do this once before I figured out that I'd didn't put the trigger unit in the right place when I installed a new vent valve. I'd say you should jack up the right front, pull the wheel and the inner fender liner and look around. All the components are right there, including the charcoal cannister control valves. First check the fuse but it doesn't sound like thats your problem if you hear a click when you move the flapper back.

Will a smoke test reveal leaks on the secondary air injection system? Is there some kind of control valve that isolates the air injection vacuum plumbing from the manifold until the DME signals the air pump to run? I've had a smoke test run on my car without showing any leaks there but nothing special was done to enable the air injection while the test was going on.

I've personally seen the Durametric display a 0410 and 1126 codes and then hooked up the generic scanner and it did not show the 0410. Also seen the 0410 by itself in the Durametric (no CEL) when at the same time the generic would not show anything. Some generic scanners will display pending codes but not my cheap Walmart unit. Personally I say go for the Durametric if you plan on keeping the car for a long time. It's fun to use and lets you activate functions. I wasn't sure if my fans were working in both the low and high speed modes so I tested them through the Durametric with the motor off and could easily hear both modes. I'm ordering a fuel pressure test gauge and I'll use the Durametric to turn on the high stage of the fuel pump. The downside to the Durametric is the lack of information about the meaning of the values you obtain from the sensors. I'm chasing down my 1126 code, which means the car is running lean. It was hard to find someone who could explain the data. According to an expert at another web site my car is running rich at low loads and lean under higher loads, pointing toward a MAF or fueling issue. In this case the Durametric is (maybe) pointing at a non-obvious solution since typically folks assume vacuum leaks are the most likely cause for the 1126 code.

Thanks. I did buy a book called the "Boxster Maintenance & ODBII Manual" thinking it would provide a detailed explanation of the car's systems, etc but it only has about 1 page per code and doesn't describe the theory of operation or the evaluation of diagnostic data. It must be a different book than the one you mention. I am interested in buying the more complete book if anyone has a link. I guess the "LV" in "CLV" must be Load Value. I don't understand the negative values reported by the Duratmetric for RKAT data points. I guess I need that book. Somehow I was getting the impression (totally guessing) that 0 (zero) might be the ideal value for points labeled adaptation with the actual number reported being a percentage of the permissable range of compensation being applied by the DME. Minus numbers would represent one direction (lean vs rich) and positive the other. That's all guesswork lacking "the book". The basic idea I have is that my car's failure mode (CEL stays off for a long time after clearing, car runs great) might be pointing to an intermittantly bad sensor, such as the MAF (shop wants to put on a new one.) If that was true I'd see pretty normal values from the data points except when the bad sensor was acting up. The other failure mode would be if all the sensors were working OK. Then I would expect to see data values that signify a pretty strong vacuum leak and those values would improve after each incremental repair fixed another leaking item. Obtaining and understanding the Durametric values is an attempt to see which of those two scenarios is most likely.

The main question I wanted answered was not whether or not I have an air leak. What I want to know is how to use the Durametric to understand and monitor the performance of the car. I would be grateful if you or anyone else could shed some light on the actual numbers I posted, the measurement units, their meaning and especially numbers from the same data points on Boxster motors in tip-top condition.

I'm sorry, it wasn't 1124 - I was going off my memory about the previous codes. It must have been 1126, 1128 and 1130.

My 2000 S Tiptronic that I bought back before Christmas has been throwing codes indicating the motor is running lean and I've fixed one vacuum leak on the oil fill tube with one other fix pending on the line going to the brake booster. The codes are 1124, 1126 and 1130. I bought a Durametric unit that often shows an additional code of 0410. The ODBII maintenance manual says 1126 is "Oxygen sensor adaptation range 2 (cylinders 4-6) enrichment limit". I cleared the 1126 and 0410 codes and took a 30 mile ride last evening and obtained the following readings idling in my driveway at the end of the ride. The motor seemed to run perfectly as near as I can tell. The Durametric showed "no faults" at the end of the drive. Typically the CEL comes back on after about 200-350 miles. Loss Adaptation Idle .08 Adaptation range 2 FRA Bank 1 1.27 Adaptation range 1 RKAT Bank 1 -2.58 Adaptation range 2 FRA Bank 2 1.24 Adaptation range 2 RKAT Bank 2 -2.39 MAF sensor volts at idle 1.30 I don't understand any of the above except that the MAF sensor volts seems OK. Are these the correct data points for monitoring long term fuel trim? What do the terms "range 1" and "range 2" mean? What do FRA and RKAT mean? What are the units of measurement? What do the values signify? What are ideal or good values on a Boxster motor that is running well? What kind of numbers would show running lean vs running rich?

I figured this out and fixed it yesterday. About a week ago I replaced an item Porsche calls a vent valve near the filler cap. The trigger unit actually fits inside a recess on the plastic housing of this valve. I didn't realize it when I took it off (the plastic housing broke while unscrewing a stuck bolt and the trigger unit came loose at that moment without me noticing). Anyway I'm back in business. Here is a picture of how these two parts fit together. BTW you get a new trigger unit when you order a vent valve. I thought the supplier made a mistake and I actually thought the trigger unit was a brake pad sensor that escaped from somebody else's order.

I've been working on a odd sound coming from my fuel tank cap area and I mistakingly moved a funny looking item that I now believe is the trigger unit for the gas tank vent valve. Now my car won't accept gas when I try to fill up. Here is a picture. Can anybody tell me exactly where it's supposed to go?

I bought a 10 year old Boxster with 100k on the odometer, so somebody must have used it as a daily driver but if you live where it snows a lot I don't think it would be a good idea. I remember the TV broadcast this winter during a snowstorm somewhere and a Boxster was spinning out. Even if you get winter tires the ground clearance would likely be a problem. Not to mention the salt damage.

OK, some progress today at the local foreign car shop in Hot Springs, AR. They hooked up their smoke testing machine for locating vacuum leaks and found a pretty big one on a line that exits the driver side intake manifold right behind the driver's back. The line turns left and runs about 6" then goes down to the bottom of the car and I think it goes forward at that point. The reason I don't know for sure is that I was in the car raised in the air wiggling the line while the 2 mechanics were underneath making sure they knew which one it was. Looking at the shop manual and parts diagrams it must be the vacuum line to the brake booster. Possibly part # 996 355 577 42 for a 2000 S but I can't find a diagram in the parts catalog that specifically shows the hose from end-to-end. It would have to be a pretty long convoluted hose if it's one piece. The main point of this post is how valuable the smoke testing tool is. I doubt a home mechanic would have found this leak and I know for sure that one Porsche shop didn't find it when they searched for leaks and didn't use a smoke machine. The line was rubbing against the chassis as it turned down from the top of the motor. The mechanic said he saw a small wisp of smoke and then when he wiggled the line it blew out smoke like crazy. And although the full story isn't over until I get the line replaced and spend enough time with the car to know it's fixed for good, this also points out that jumping to a conclusion that it must be a bad MAF sensor might be expensive and frustrating. Not saying it still couldn't be a sensor but I'm glad I searched for the fundamental stuff first.

Do you still have the codes after getting the car running with the new battery? I guess you might not know for a while because some take multiple driving cycles before showing up. Nice that you got the car running again anyway.