JFP in PA

The clutch assembly at the front of the compressor has a large bearing in it, which can seize. I don't think Porsche sells the clutch and bearing separately from the compressor, but you may find it in the after market.

You should hear the fan, but it should not be overly loud. They can start to make noise when the electric motor is going south or if something has damaged the blades or stuck in them.

The crank pulley should not "wobble".

Not really, FTIR analysis is useful as a continuous "on-line" analytical tool for diesel engines in environments such as engine test cells where the engine is running and the FTIR is automatically collecting data. FTIR is not as accurate as either GC or FI techniques, but they are both very expensive and are also "batch" samples techniques (read you take a small sample of the oil and inject it into the instrument), which makes them difficult to automate for long run auto sampling testing.

Thanks, but unfortunately, none of these address it issue of fuel dilution concentration accuracy between the two types of tests (flash point vs. GC or FI), which I have told is considerable; plus the fact that flash point analysis can be misinterpreted due to the impact of other factors on the oil which tend to give higher volatile's concentrations which are falsely attributed to increasing fuel dilution.

If the 996 follows the lead of the early Boxsters and 18" wheels, the chassis will develop cracks at key suspension mount locations. Porsche's wheel and tire size limit recommendations only concerns normal street usage, so staying off the track is not going prevent the problem from starting, it just may take longer. Once the car starts to develop these failures, it is nearly impossible to hide and will totally kill the resale value of the car if spotted in a PPI. Any disturbance in the OEM paint, such as the use of sound deadening overspray's on these locations immediately raises questions and lowers prices, if the car is even saleable. At the end of the day, it is your car and your money, so proceed as you please; but the TSB exists for a reason............

Loren, What makes the 19" wheel, "not approved for use on the 996 series cars"? Thanks, Offset and the fact that like the early Boxsters (which could not use 18" wheels), the chassis was not reinforced to handle the load of 19". Covered in Porsche TSB 18/04 4440.

Your problem sounds more like a mount issue rather than a clutch problem. In order to check out the mounts, you are going to need to access and inspect them, looking for tears or deformation in the rubber isolation sections. Most commonly, they tear with age, causing symptoms like you are describing. Both the engine and transmission have mounts, and it would be a good idea to have a reference source on hand while doing the inspection, such as the Bentley 996 manual, which gives you both photos and diagrams to work from as well as "how to" information on removing and replacing any of the mounts.

Orient Express is on the money, on your car the only information the PSE gets from the car is the ground speed to close the system and comply with European noise regs. No coding or activations are required to get the system to work.

First of all, the A/S 3's are an all season tire; good all around, but not as crisp handling or responsive as a summer tire would be.

Year and model would be helpful.

More to the point, I've been talking to labs that do UOA work, and a couple have told me that if a lab is using flash point analysis (cheap, quick, but grossly inaccurate) to determine fuel dilution levels, that alone can generate results similar to what you saw. From my discussion's with them, the recommended method to do fuel dilution in engine oils is by head space gas chromatography, or by flame ionization chromatography. While they seem to feel that flame ionization is the more accurate of the two methods, both only heat the oil sample to 300F to get the fuel off for measurement in the dector. That point alone seems to contradict your theory. I'm going to keep digging on this subject. I have inquiries into contacts I have inside the oil industry (started my career off working in the R&D group of one of the then big ones) to see if they can shed any light on the subject. Stay tuned.................

Hey jl-c, I just put Edge 5W 40 in the Turbo S. This is what Audi uses so I have a common oil with My wife's SQ5 for the time being. I plan to switch both cars to Millers after they hit 10,000 miles (broken in). That Porsche recommendation is only 1/2 right. Moisture (H2O) does indeed boil off as you heat up the oil but fuel does not. Once the oil is diluted with fuel it is permanent. If you look at the UOAs of my C4S as you get more miles the fuel dilution only increases in a linear fashion. By 6,000 miles the oil is diluted enough to lose a viscocity grade. So, I do not go longer than 6000 mile between oil changes in that car. Each car is different so, the only way to know what is going on with your car is to run serial UOAs until you have it figured out. Porsche's recommended oil change interval is more political than anything. You can go 10,000 miles but I wouldn't, at least not in my C4S. Millers is the absolute best as Luke's, mine and now Dus10R's experience shows. I am absolutely sure that wear rates fall off with this oil formulation. I'm not sure I can agree with your comments on fuel dilution. Nearly all the components in gas have considerably higher vapor pressures than water, so if the water is boiling off, the fuel should have preceded it. I think the issue may be how (the analytical technique) your UOA lab is measuring fuel dilution, they may be seeing accumulating fuel additive's that remain after the fuel actually flashed off, which would give the impression of increasing fuel dilution with time. It has nothing to do with vapor pressure JFP. It has to do with solubility and the polarity of the various molecules. I discussed this before when I explained fractional distillation. This is a mistake many people make. The UOAs are quite predictible in this reguard and reasonably accurate. Fuel does not boil off once it is desolved in oil. In order to separate it you have to heat it all up to 1000 degrees and catch the molecules as they condense. This is how oil refineries work. Non polar molecules attract each other in solution but repell polar molecules such as water. This is why the water boils off. I am going to have to look into this subject a bit deeper; I am find many references to the fuel dilution flashing off when an engine reaches both full operating temperatures, and some level of vacuum in the sump, and nothing (yet) to support your point. We will come back to this topic.................

Hey jl-c, I just put Edge 5W 40 in the Turbo S. This is what Audi uses so I have a common oil with My wife's SQ5 for the time being. I plan to switch both cars to Millers after they hit 10,000 miles (broken in). That Porsche recommendation is only 1/2 right. Moisture (H2O) does indeed boil off as you heat up the oil but fuel does not. Once the oil is diluted with fuel it is permanent. If you look at the UOAs of my C4S as you get more miles the fuel dilution only increases in a linear fashion. By 6,000 miles the oil is diluted enough to lose a viscocity grade. So, I do not go longer than 6000 mile between oil changes in that car. Each car is different so, the only way to know what is going on with your car is to run serial UOAs until you have it figured out. Porsche's recommended oil change interval is more political than anything. You can go 10,000 miles but I wouldn't, at least not in my C4S. Millers is the absolute best as Luke's, mine and now Dus10R's experience shows. I am absolutely sure that wear rates fall off with this oil formulation. I'm not sure I can agree with your comments on fuel dilution. Nearly all the components in gas have considerably higher vapor pressures than water, so if the water is boiling off, the fuel should have preceded it. I think the issue may be how (the analytical technique) your UOA lab is measuring fuel dilution, they may be seeing accumulating fuel additive's that remain after the fuel actually flashed off, which would give the impression of increasing fuel dilution with time.

Yep. Pulled everything from my 01 which functions perfectly. Tried this. No change. I'm suspect of the physical connections. Thinking about pulling the seat to take a better look. Although key fob talks to immobilizer which activates horn/locks. Q: durametric enthusiast cannot reset alarm/immobilizer codes apparently. Would these be stored outside the DME/immobilizer unit??? Elsewhere in the car where a battery(coin cell) fed storage unit stores flash or something? Running out of ideas. Also of note -- litronic ballasts appear to be MIA. And power seat control module is missing. Cable actuated hood/frunk latch are "locked". I wouldn't think these matter but that's about all that I can see left to address. Durametric system has never been able to code the immobilizer/alarm system, that requires access to a PIWIS or PST II.

OK, here is an M96 out of the car (1999 C4), and the water pump has the black pulley towards the lower left of the photo: As you can see from the photo, there is not a lot above the water pump, other than the engine case. You need to shine some light in there and clarify where it is coming from...............

A 99 C2 would be a 5.2.2, a 99 C4 would be a 7.2 DME. An 01 C2 would also be a 7.2 DME.

If you take a look at the photo Ahsai pointed out: You will note a square opening on the right side of the pump cassette. When in the car, that has a flat plate over it held on by some small bolts, and it can leak water if the gasket behind it fails, or the bolts come loose.

If the thermostat and pump mating surfaces are completely clean, and no sealant was used, and everything is properly torqued, something else is leaking.

Just be aware that these things wear with use, so buying a used unit could put you a couple of shifts away from the same place you are now..............

I believe you will find one in the Bentley manual.

Original part #986-325-612-01, but that may have been superseded, so check with a dealer. Retails for around $400.

My first question for the shop you took it to would be "What type of diagnostic scanner are you using?" If the answer is not a PST II, PIWIS, Durametric, or Autologic system, they cannot even see several of the key system that need to be tested.

This could be a number of small issues (sensor failures, etc.). If you do not have the expertise and the proper equipment to evaluate it, I would suggest taking it to a pro.

Glad to be of help, and that you got it sorted.