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Quote from the article:"[T]hese all-new engines are surprisingly trouble-free -- especially in comparison with Porsche engines of the early 1970s." Great achievement. If all else fails, lower your standards! And because the all-new engines are so great and so much better than all the old rubbish, Porsche still has to use the old crankcases for their Turbo and GT3 engines. Cheers, Uwe

Being an automotive engineer myself, I have talked at considerable length with colleagues at the Porsche factory, at seal manufacturers and at various research institutes. The reason why the RMS fails is well understood and is a result of the 996's revolutionary crankcase design, which consists of a separate crankshaft carrier which is bolted into the actual crankcase, rather than the crankshaft running directly in the crankcase link in normal designs. Because the crankshaft is running in the crankshaft carrier, whereas the RMS is located in the crank case, you get vibrations between the crankshaft and the RMS, which ultimately destroy the RMS. With a conventional crankcase design, this can't happen, because both the crankshaft and RMS are located directly in the crankcase, so there can't be the same kind of vibrations between the two. Also, with the 996 design, the distance between the last crankshaft bearing and the RMS is much greater than with a conventional engine, where the RMS comes right behind the last crankshaft bearing. The increased distance between RMS and crankshaft bearing means that the flex of the crankshaft results in a higher lateral movement of the crankshaft at the point of the RMS. In oder to reduce the distance between last crankshaft bearing and RMS, Porsche developed a new tool that places the RMS deeper into the crankcase, i.e. closer to the last crankshaft bearing. The problem is worse with the 3.4l engine, because the gearbox drive shaft only has two bearings, therefore the whole crankshaft/flywheel/drive shaft system vibrates even more. With the introduction of 3.6l engines, GETRAG added a third bearing to the drive shaft to reduce these vibrations. Automatic gearboxes also have a better support of the drive shaft, this is the reason why the RMS problem isn't quite as bad with automatic gearboxes. Porsche attempted a new solution with the 997 engine: They added an extra bearing to the crankshaft carrier of the engine. The extra support and reduced distance between the new bearing and the RMS is supposed to reduce vibrations. Obviously there are other reasons for oil leaks in this area: Slightly off-centre crankshafts, failing intermediate shaft seals, leak in the actual crankcase (inadequate sealant application or casting problems), but the vibration issue is the reason why most RMSs eventually fail. Since the problem is inherent in the 996 engine design, it is unlikely that the new seal will solve the problem. Otherwise, Porsche would not have redesigned the crankshaft carrier for the 997. In fact, I have not come across a single engineer who thought that this would be the solution. Sorry. My car had the new 997 seal fitted at the factory three weeks ago, but for above reasons nobody sounded very confident that this will solve the problem. I'll keep you posted if and when it fails again. Cheers, Uwe

Hi Paul, It's almost always the top ball bearings. Well known problem, particularly when it't hot. Re-greasing doesn't really help, they need to be replaced. Problem is that it's not a permanent solution. I'm on my third set (all replaced under warranty and now I've just learned to live with it. Cheers, Uwe

Tyres can flat spot in four weeks, so I'd definitely increase the tyre pressure as suggested in the manual. I wouldn't worry too much about the battery, but a trickle charger certainly wouldn't hurt. Cheers, Uwe

As I have mentioned before, the new 996 seal is apparently the standard 997 seal. Don't know about anything about a new tool, but I'll be in Zuffenhausen at the factory next week to have my RMS changed (3rd time, 65000 mls), so I'll make some enquiries and keep you posted. Cheers, Uwe

FWIW, the new RMS is simply the one from the 997. Freudenberg made the various versions for the 996, I don't know if they have changed supplier for the 997 (KACO?). Cheers, Uwe

Hi, That's the pressure relief valve, which limits the maximum oil pressure to slightly under 5 bar. If you leave out the washer, you increase the preload on the spring, so you would slightly increase the maximum pressure. Don't know if it makes a big difference. I'd get a new washer, it's a rubber/metal design.

Hmm, did your car get a new engine? As Loren pointed out, the first number is in the normal format and seems to be a MY 2002 engine. The second one i've never seen, but it would look like at MY 2005 engine. "AT", which is not the formal format, might stand for "Austausch", which means "rebuild" engine. Just a wild guess, because in the old days rebuilds would just have an "X" added to the engine number. If it is really important to you for your concours stuff, send me a PM and I'll find out for sure in the factory in Stuttgart. I'll be there next time in two weeks' time. Cheers, Uwe

Well, the proper way to do it is with a Porsche System Tester: You let the car idle. Then you use the PST to switch the timing on one bank. The idle should change and become lumpy. You change it back, and it becomes smooth again. Then you do the same with the other bank. It's worth checking out, because if one bank runs on early and one on late under high load, the cylinder head can overheat. The cam position hall sensor is important in this context too, because the DME compares the signals from the crankshaft sensor and the camshaft sensors to determine if the timing is set to "early" or "late". Cheers, Uwe

Hi, this would be consistent with a defective oil separator and can seriously damage your engine. Known problem with the older models. I'd have it checked out by a garage ASAP and certainly would not redline it. I don't want to cry wolf, but it's certainly a possibility. Cheers, Uwe

Don't yank at it. It's clipped in, so you need to press the little release at the side of the plug to pull it out.

Yes, why would Porsche know ... :rolleyes: If your coolant "gets dirty just like your oil" then you've got a major problem with your engine. Cheers, Uwe

People say a lot of things on the internet :). The factory workshop manual states: "Note: The engine cooling system was filled with a lifetime coolant filling at the factory. This coolant must not be mixed with or replaced by other coolants." I'm sure Loren can confirm this. Also, if you look at the maintenance checklist available on this site you'll notice that no coolant changes are prescribed. Cheers, Uwe

I'm not sure if super-glueing is likely to be a permanent solution. Usually the emblem gets damaged when people press on it to close the bonnet. I'd probably buy a new one, over here they are about 45 Euros, so I guess that'll be about 50 bucks. Cheers, Uwe

Just out of general interest: Why do you want to change the coolant, considering that it's a lifetime filling and, at least according to Porsche and the coolant manufacturer, does not need to be changed? Cheers, Uwe

I'd say it is wrong. If you look at the TSB on transmission oils, it says "Transmission oil SAE 75W-90 for manual transmission, front-axle drive (C4), and rear axle final drive (Tiptronic transmission)". Cheers, Uwe

:oops: Altough you had said it earlier on, I didn't realise that PTX isn't sold in the US. I was thinking why the h*ll do they want to use a different oil? From the specs you can't tell if Mobilube SHC is OK, the specification GL-5 alone is far too general. There are quite a few different GL-5 oils around, particularly for different kinds of LSDs (limited slip diffs), with varying amounts of EP additives and friction modifiers. You definitely don't want a high EP content in your gearbox oil. However, I had a look at the spec sheet on Mobilube 1 SHC 75W-90 and concerning the EP content, they say "where mild extreme pressure gear lubricants are recommended". It also looks like it is specifically designed to work in the gearbox and differential: "Wide multipurpose capability: One lubricant for heavy duty manual transmissions and rear axles". AFAIK Mobilube is still developed in Hamburg/Germany. If I've got time I might give them a quick call tomorrow and see what they say. Cheers, Uwe

Goodness, that's appaling. However, give the build quality of my car, perhaps not entirely surprising. Where did they end up last year? And is there a link to a web site with the actual ranking? I found the JD Power site, but couldn't find the ranking. Cheers, Uwe

I don't think I would. For the reasons explained above (gearbox and diff in the same casing and hence using the same oil), I'd use a transaxle-specific oil. Almost all major oil manufacturers make them, Mobil 1 calls it PTX, Shell calls it Transaxle, Castrol calls it TAF-X. There is a reason why Porsche (or in fact GETRAG) recommend a specific oil. Obviously you can pour in whatever you want, but if you knowingly discard the manufacturer's advice, then don't complain if your gearbox (and in particular the synchromesh) doesn't last as long as you might have hoped. Also, I wouldn't necessarily go with people's recommendations "ABC is a good oil for Porsche boxes". Very few people understand the specifics of gearboxes, not even car manufacturers themselves (they just buy them in) and certainly not the mechanic at the dealership. But why not just go with the gearbox manufacturer's recommendation and be on the safe side? Cheers, Uwe PS: I know that the old G50-bases boxes used any old 75W-90 API GL5, but the synchro was different and the change intervals were shorter.

Hi, Porsche recommends Mobilube PTX or Shell Transaxle, both 75W-90. I'd stick with these. Reasoning: Gearbox oil these days is quite gearbox-specific, much more than engine oil. Porsche gearboxes are quite unusual in that they contain both the gearbox and the differential. Normally, differentials want hypoid API GL-5 oil, which is very low friction and withstands the extreme pressures of the differential. This low-friction GL-5 is not ideal in a normal gearbox, because the low friction doesn't let the synchromesh work properly. Therefore, normally gearboxes take GL-4 oil and GL-5 oil is not recommended. Unfortunately, in the Porsche box you need one oil for both diff and gearbox, so Mobilube PTX and Shell Transaxle are specially designed GL-5 oils that let both the diff and the synchromesh work properly. Cheers, Uwe

I wouldn't close the bleeder screw as soon as I see clean fluid. The Porsche workshop manual recommends that you bleed about 250ml (about half a pint) of brake build per caliper. Whilst 250ml might be slightly excessive, it would wait until I see at least 50-100ml of clear fluid. The car and brake manufacturers' reasoning behind it is this: 1) We want to sell expensive brake fluid to our customers :clapping: 2) Within the calipers and abs pressure modulator there are quite a few recesses and awkward places where it takes a while for all the old brake fluid to flush out. So if you start seeing clear brake fuild at the calipers, it is good practice to let it run for a little while to make sure that all the old fluid has come out from these awkward spots. The second point brings me to the recommended pressure of the bleeder. Porsche recommends 1.5 bar (I guess about 20psi). As "ar38070" pointed out, that's not ideal with a Motif bleeder because you are pressing wet air into the brake fluid. That's a design flaw of the low-cost Motif bleeder. Professional bleeders solve this problem by either using an electric pump to pressurise the brake fluid, or in pneumatic systems similar to the Motif bledder they use a membrane to separate the brake fluid from the pressurised air. However, I probably wouldn't recommend reducing the pressure below 1.5 bar, even with a Motif bleeder. With reduced pressure, you decrease the speed with which you press the fluid through the lines. However, high speed is desirable because again it makes sure that the old brake fluid is flushed our from all the awkward places such as the pressure modulator and calipers. This is particularly important because the old brake fluid containts a significant amount of water which can lead to corrosion problems (apart from a decreased boiling point). Therefore, I'd probably stick with Porsche's recommendation. Cheers, Uwe

Hi, There are different types of antifreeze, and some are not compatible with each other. In fact, they are so incompatible that they can turn into some gelatinous gunk. You need to use Porsche antifreeze or one that is compatible with Porsche. See also this thread: Antifreeze thread Cheers Uwe

Very useful! Thanks a lot, Uwe

Hi, make sure you get the right logo. From MY 2002, Porsche moved the positioning of the logo to the bottom of the lid. The problem is that the new logos only fit in the new position, not the old one. Basically the curvature of the lid is concave at the bottom and convex at the top, so they had to make different logos. It's the top of the "C" in "Carrera" that is curved differently. So if you try to stick a new style logo in the old position, the top of the "C" will stick out. Not all dealers know this. Cheers, Uwe

Hi, The Carrera control unit was made by Hella, the Cayenne and Touareg units are made by BHTC, which is a joint venture between Behr and Hella. BHTC also have a US subsidiary in Plymouth, Michigan. Maybe you want to contact them directly. Cheers, Uwe