996TT, DME

2004 996TT W/X-50. Any known problems with these [DME]? Any ideas on what a replacement DME costs? Did the 2004 996TT come with tire pressure monitors? I know that 2005 was the first year of no spare tire. I am also aware of the coolant fittings issues. Thanks!

Quotes source post: 12114910

The DME for these cars is pretty reliable. I can't recall reading about one failing. Avoid jump starts. Avoid unnecessary battery removal/installation. If you have to jump start the engine or have to swap the battery pay close attention so you don't hook something up wrong. If you do any work on the car be sure you avoid static discharging into a say a MAF connector, or an O2 sensor connector, any connector actually for almost all wires run to the DME. Have no real idea of the cost of a new DME but a WAG would be between $1000 and $2000. Easy enough to find out. Just get a quote from your local Porsche dealer parts counter. There are businesses that "rebuild" these, at least for some models: Boxster, and the NA 996. I haven't looked but these business might rebuild the 996 Turbo DME, too. No TPMS hardware. IF you are thinking of buying a 996 Turbo there are more things to consider than the ones above.

Yes, I am considering a 996TT W/X-50. I am not aware of much more than what is listed above except the automatic wing giving out at 20,000-30,000 miles. Please enlighten me on further problems with these. Thanks, DWDunn

Quotes source post: 12116084

Well, first the car is just a used car so you want to be sure you can give the car a thorough used car check out. My advice is to arrange to visit the car with the engine dead cold. Turn on the key and be sure the CEL comes on then goes off. Be sure the A/C is off. If this is on the fans run all the time and this tends to keep the engine a bit cooler and can mask an overheating problem. You will check the A/C later. Start the engine and let it idle while you walk around the car car looking the body over. While you are of course interested in what the body looks like you are listening to the engine for any scary noises as it starts running from cold and warms up. Ideally it would be nice to let the engine idle long enough to be able to check the oil level but this can take 10 minutes or more of idling time. After this then have the seller take you on a test ride. The route should cover 15 miles and give the driver a chance to demo the car in a variety of scenarios. Within reason you want to experience the car as you intend to use it. Pay close attention the car/engine as the car is driven. Back at the starting point then you take the car out as the driver. Cover the same route. Drive the car the same way. If after the above test ride/drive then back at the starting point then you give the car a thorough used car check out. Assume nothing works until you have confirmed it does work. What to specifically check? Well, everything. If point you to the spoiler you might miss a bad headlight and the ballast/starter in one of these things can run nearly $1000 to replace. If I point you to the radiators then you miss a 6-speed that jumps out of 2nd gear. If I point you to the front diff and possible leaking axle flange seals you miss power seats that no longer work right. But based my experience with my car over the years I can point you to some biggies... Spoiler as you know. Any signs fluid leak, if the thing doesn't go up smoothly and evenly or fails to come down in the same fashion that's a bad spoiler hydraulic system (probably) and that's $2K to replace with factory new hardware. Some have "rebuilt" this and met with some success. If a manual tranny sure the tranny doesn't jump out of gear, any gear, not just 2nd. After the car/running gear is fully up to temperature listen for a high pitched whistling noise. If this is going to appear the odds are high it will be when one coasts up to a stop light with the manual tranny in neutral and the clutch pedal released. If you hear the noise press down on the clutch pedal. If the noise goes away this is from a high pressure relief valve in the power steering fluid reservoir that is only available in a new tank. If the car is equipped with a manual transmission be sure the clutch accumulator is good. A sign is if you when you go to start the engine and press down on the clutch and the clutch is hard to depress. This can be a sign the accumulator has lost boost over time. After you start the engine the boost should appear almost instantaneously. If when the engine is running and you push down on the clutch or release it if you feel any pulsing this is a sign the accumulator is bad. A test of the accumulator is to with the wheels straight ahead and without turning the steering wheel start the engine and let it idle 20 seconds. Turn it off. Then fully depress the clutch pedal then release. No need to do this real fast or real slow. Just pick a rate that is ok with you. Count the number of times you do this before the clutch pedal gets hard to push down. My info as to the number of times that indicates the accumulator is ok varies. Some say over 30 times. Some say fewer times. My experience is if the accumulator is bad the pedal will get hard in just a few pushes/releases. After the pedal effort goes way up then start the engine again and let it idle 20 seconds. Shut off the engine. The pedal should be easy to push again. Look for fluid stains on the plastic panel under the front trunk lid on the driver side of the car. The clutch slave cylinder can act up and fluid leaks past and the power steering fluid reservoir level gets low while the small reservoir under the panel gets too full of fluid and this leaks out. Be sure both radiator fans run and blow the same amount of air. Ideally it would be nice to have these come on from the engine coolant temperature being hot enough to trigger. This can be the case if after your test drive you park the car and let the engine continue to idle. You can use this time to verify the engine compartment fan works. In some cases this can run all the time the engine is running. (The fan in my Turbo does this.) This I understand is a function/feature controlled by a fuse in the fuse box. If this fuse -- I forget which row/number of fuse -- is absent the fan only comes on when the engine compartment temperature gets above a certain temperature. Also, if you continue to let the engine idle after the car has been test driven then if there is a coolant leak you have a better chance of catching it as you will get a whiff of anti-freeze. (It was just such a whiff that clued me in my car's water pump was leaking.) But the leak can be at the front from one of the 3 radiators. (Earlier this year all 3 of in my car were found leaking and had to be replaced.) If you have the presence of mind, when the engine is idling as soon as you hear the radiator fans turn on shut the engine off. The heat load in the engine raises the coolant temperature and pressure and if there is any leak in the system the odds are high it will make itself known. Let's see... what else? Oh hot idle oil pressure should be in the 1 to 2 bar range. Even in blazing hot temperature with 0w-40 oil in the engine the lowest I've seen the hot idle oil pressure get is just a touch above 1.5 bar. The voltage gage should read about 14V after a cold engine start and after the car is driven some distance -- 15 miles -- the level should drop to around 13.5V. The level can vary depending upon the electrical load. If you flip on the lights, or turn on the A/C the voltage level can drop as less voltage gets routed to the battery as more is required for the other electrical loads. The coolant gage doesn't vary much. The thing is pretty heavily dampened so the needle just hangs around the 180 degree hash mark. After the hot engine has been off a while check the coolant tank cap for any signs of condensation. This can be from a leaking cap -- common -- or a leaking coolant tank. The above is not a complete list, but you get the idea. After all of the above (and more) then if you still like the car and believe you can buy it for an agreeable sum of money arrange for a PPI by someone who knows these Turbos inside and out. Among other things the PPI gets the car in the air so a thorough inspection can be made underneath. Check for RMS leak or any sign of a leak from any part of the engine, turbos, turbo oil lines. All hoses/fittings want to be checked for any leak sign. The engine coolant hose fittings are glued (epoxied) into the block and this epoxy has been known to fail and one or more fittings leak. To repair this is an engine out job. The water pump can leak. Look for antifreeze residue build up behind/under the pulley. Check the belt for sharp edges. A sharp edge is a sign the belt is rubbing and this is a sign some accessory drive (water pump most likely) has excessive bearing/shaft play. Check all transmission seals and rear and *front* diff seals. Check the CV boots for cracks. Check the power steering lines for leak sign and check the steering rack for leak sign. Give the rack dust boots a grope. If they feel like cheap breast implants the rack seals can be letting power steering fluid past. This can be due to a bad high pressure relief valve that is routing too high pressure power steering fluid to the rack. Check the radiators for any leak sign. Look along where the bottom of the radiator and the core join. If a lot of trash build up in the radiator ducts the odds are good there'll be a leak if not now soon as the radiator and condenser can corrode. Look for differences between head lights or radiators/condensers. If a difference this can be a sign the newer ones were installed in the course of repairing the car after an accident. Tire wear will be noted. Often the rear tires wear on their inner edges. This is -- based on my experience -- a sign of an alignment problem. I'd like to see all 4 matching tires, N-rated tires, of course. A more heavily worn right rear tire comes from the absence of LSD. Check the wheels. The hollow spoke wheels are expensive to replace. Check brake pad thickness and rotor thickness -- a 1mm lip at the outer edge of a rotor is a good sign the rotor is due to be replaced -- and condition. No cracks or signs of severe scoring or overheating. The caliper paint should not be discolored for if it is this can be a sign the brakes were overheated. Look for rubber tire marbles on top of the plastic underbody panels. The presence of these is a sign the car has been tracked. Lots of trash can be a sign mice or rats have been in the car. The DME over rev counters and time stamps and total engine run time should be read out. If anything of any concern the PPI guy should go over this with you. And so on. A good used car check list is the list the techs use when CPO'ing a car. While you may not be abel to do all the checks the ones you can do can go a long way to helping you build up some confidence the car is in good condition.

WOW! Hey Macster, thanks so much for all of the info! And thanks so much for all of your time you took to pass on these words of wisdom/experience! I will print this and take it with me [if the car hasn't been sold]. I see you are in Livermore. I'm 40 minutes east of you in Riverbank. I am doing a re-landscape project in my front yard because of the drought. I am doing the work myself and am planting drought tolerant plants with rock, gravel and boulders. This drought is not from 'climate change'. California has a history of droughts that last from 50 to 150 years. The 'Ancient Bristle-cone Pines' have kept records for us going back almost 9,000 years. The oldest tree [Methuselah] is just over 4,700 years old and is still alive. California came out of a 50 year drought in 1848. We didn't start keeping records until 1850. What the record [from the trees] shows is that we have been in a wet cycle starting in 1850. Quite interesting, no? Again, thanks so much for the great information!