996 Buyer’s Guide

I wrote this article a few years ago and posted it over at the old Porsche Forums/German Auto Forums, and I still get a lot of emails every week about it.  Essentially, the same questions were popping up over and over, so I compiled some information related to my experiences working on 996’s.

Pre Purchase Inspection: I can not recommend a PPI enough, unless you are a professional Porsche mechanic. Typically they run from $150-500, and is money well spent. A good PPI will include a printed document that covers inspection of all aspects of the vehicle. They will look for a lot of issues that I will talk about later. Typically the potential buyer will pay for the PPI. This information is solely for the buyer, and the seller should not have access to this information, since he did not pay for the inspection. Make sure you discuss this with the person inspecting the car, so that there are no misunderstandings.

Background: The 996 version of the Porsche 911 ran from 1999-2005 in the states. It was produced in a C2, C4, C4S, as well as the Twin Turbo package.

Repair Cost: Everyone will experience different labor rates depending on which dealer or independent mechanic you have your car serviced at. Some dealers are quite affordable, while others will charge $250 for an oil change. This will all depend on your area. A good independent Porsche mechanic can save you a lot of money. Make sure you budget maintenance into your overall purchase price of the vehicle. Also, keep in mind that a major failure with a Porsche can cost you a LOT of money, so you may want to look into aftermarket warranties, or Porsche certified (CPO) which still have a warranty remaining. Keep in mind, at one time the car was very expensive, and because it depreciates in value, doesn’t mean the parts and labor get any cheap. You are still paying to maintain a Porsche.

Porsche 996:
Upkeep: Some of the more common failure/maintenance points:

Rear Main Seal: The C2 and C4 engine is prone to rear main seal leaks. While the internet makes it seem like a huge deal, it is not as common as one might think. Well I shouldn’t say it isn’t common, but a leak bad enough to even leave a drip of oil on the ground is pretty rare. You can usually find a hint of wetness at the bellhousing on most 996’s. No big deal. It is definitely something to look for when purchasing a 996 though. Cost of replacement can typically run upwards of $1500 since you replace the clutch while you are in there. The updated seal used is a 997 part number. Typically, if the engine does not show a leak at the RMS by 15k miles, then it will not likely occur. The RMS issue does not exist in the turbos, as the engine is the traditional flat six, split case design. I am sure they still occur on occasion, but not nearly as often. When should you replace the seal? When the oil drips on the driveway start to annoy your wife. Will it hurt anything? No, but a severe leak will obviously lead to decreased oil in the engine over time, and could lead to engine failure if you do not add the oil it is losing. The intermediate shaft bearing (flange) can also leak and mimick an RMS leak. It is located directly under the RMS area.

Clutch:Typically clutch life will be around 50-60k miles if driven hard. This will all depend on the driver of the vehicle though. I have seen clutches go out around 30k miles, and some cars with 70-90k miles on the original clutch. Cost to replace is roughly $1500 for C2/4. For the turbo, expect around $2500-3000 due to twice the labor rate (18 hours), and a more expensive clutch.

Stiff Clutch Pedal: Typically a very stiff clutch pedal in the C2/4 is indicative of a bad throw out bearing guide arm. There is an updated arm and release bearing which will alleviate this problem. Again, you are looking in that $1500-1600 range to have it replaced.

Tires: Porsche put quite a bit of negative camber and resultant toe into the rear suspension, and along with the weight of the engine being over the rear tires, tire life is much shorter than a standard car. Typically 15k-20k miles out of a set of rear tires is doing very well. Due to the negative camber/toe, the insides will wear out first, while the outside tread will still look good. Front tires will last longer, and typically you will get twice the life of the fronts versus the rears. You can realign the car to a more neutral toe setting in the rear and extend the life a bit.

Brakes: At roughly 30-40k miles you will probably need at least brake pads in the front. They wear almost twice as fast as the rear pads, so typically you can get a set of rears to last per 2 sets of front pads. At 60k miles, expect to replace the rotors at all corners. To replace everything front and back, expect around a $1200 bill.

Oil Changes: Typically the engines will use a Mobil 1 0w-40, 5w-40, or castrol 5w-40 full synthetic oil. Usually it will take roughly 8.5 quarts of oil, and a paper cartridge oil filter (Mahle #OC128). Some dealers will charge $60, some will charge $250 or more! Now, with that being said, the failures of the intermediate shaft bearing (discussed later) is partially being blamed on the thin 0-40 oil. Without getting into a huge oil debate, I recommend running 5w-40 in these engines.

Tune-ups: Tune ups are done every 15k miles, with major services done at 30k, 60k, and 90k miles. Minor services can range from $500 for an oil change, pollen filter change, air filter change, and inspection of the vehicle. A major service will include the aforementioned, along with spark plugs, and a much more thorough inspection of every aspect of the car. A major service can easily run over $1200.

Engine: Intermediate shaft failure: I like to call this catastrophic engine failure, because it typically will require a new engine. Some of the C2/4’s have had serious failure due to the intermediate shaft failure. Is it all that common? Hard to say based on the large number of vehicles out there, but it is starting to happen more and more. This is where a warranty will save you, as it will typically run around $15k for a rebuilt engine to be put in the car. Porsche dealers do not even try and fix the engine, they are boxed up and sent back to Germany where they are inspected. Porsche will install a remanufactured engine as a fix. Having talked to some dealer techs recently (as an independent, I have only seen 1 or 2 failures in the last 5 years), the techs have told me that Porsche has replaced a lot of engines that could have been easily repaired at the dealer. There is a fix to the intermediate shaft issue if it is caught early enough. If you hear the engine making an odd ticking at start up (something you don’t normally hear), and you shut it down, chances are the IMS can be repaired. Porsche wanted to be known as having great customer service, so they decided replacing the engine was far better for that. Unfortunately for a dealer tech, you get paid more to repair items, than to replace items under a warranty/good faith type claim. LN engineering has come out with a bearing replacement/upgrade kit for these motors. Recent evidence is suggesting that the failure is happening to LOW mileage cars that are not driven enough. Condensation builds up in the oil, seeps past the IMS bearing seal, washes the grease out of the bearing, and erodes the bearing internally. The higher mileage cars are not seeming to be affected by this nearly as much. I recently pulled a bearing out of a 100k mile 996, and it was like new. LN has a ceramic bearing which does not use an outer seal which allows oil to flow freely through the bearing to keep it lubricated and prevent erosion.

Engine: Vario cam pads: Vario cam pads should be replaced by 100k miles as they will show significant wear by then. The pads help keep tension on the timing chains and are critical to the engine.

Engine: Oil Air Separator: A failed oil air separator can cause oil to be injested back into the intake system where it will burn off. Oil should stay in your engine, not get burned off.

Engine: Slipped Cylinder Liners/Cracked Heads: The early 996’s (1999 in particular) was prone to having the cylinder heads crack, or the cylinder liners crack. Not as common as the IMS failures, but we are starting to see more and more show up. Another catastrophic failure.

Coolant Tanks: A plastic coolant tank in a very hot engine bay is going to crack at some point and leak. The tanks are about $200 with a couple hours of labor to replace. This plagues the 996 and the 996 Turbo.

Wheel Bearings: I have replaced quite a few wheel bearings now in the 996/boxsters. The sealed bearing will start to growl, like excessive road noise or cupped tires when they go. Since they are a 2 piece sealed system, they will not exhibit typical bearing play in the wheel. Not a huge deal, but it does happen.

Ignition switches: All 996 and 986 boxsters suffer the ignition switch failure. Do not take the car to a dealer for this issue, as they will make you replace the entire assembly. In reality, all that needs to be replaced is the $15 control switch. At about 30 minutes to replace, it is a cheap repair. A bad ignition switch can make turning the key feel mushy, as well as cause wierd electrical issues like a radio that goes haywire, or AC that stops working.

Conclusion: 996 prices are starting to become very attractive as they are now easily found in the teen’s. Unforutnately, I feel that you are rolling the dice on whether or not you will have a major failure. There are a lot of these cars out on the road, and so overall, the percentage of failure isn’t huge. The problem is, when it happens, you are going to put as much into repairing the vehicle as you paid for it. Everything listed above are minor issues with the exception of the cracked head/cylinder issue and the IMS bearing issue. The IMS issue is likely fixed using the LN kit, though you need to be proactive about replacing it right away. If you stay away from the 99’s, your chances of the cracked head/liner issue is greatly reduced. Buying a 2000 and later is probably your best bet for having a reliable car. The lower mile car you buy, the faster you should have the IMS bearing update kit done though. The cars are a blast to drive, and with a little precautionary work, you will most likely put gas and oil in them and continue to drive them without issue.

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Bo Brammeier

March 28, 2011 at 4:13 PM

Hey Doc, tracked you down from the GermanAutoForums. Bummer you are not there anymore but I understand. You might remember me, I live out in Cheyenne, Wyoming and asked you a couple questions about a 997. I am looking at getting one next summer and was curious whether the “S” option is worth the price? Also, still up in the air on all-wheel drive. Is that worth it as well? I really appreciate any insight you can offer, whenever you get a chance. I enjoy keeping up with your projects. Thanks


    March 28, 2011 at 4:59 PM

    Hi Bo.

    I am currently out in Cheyenne visiting my parents and sister/brother in law. Love it out here! If I were buying a 997, I would probably spring for the S version. A little more hp is never a bad thing 🙂 AWD is nice, and the system is pretty bulletproof. It makes the car heavier, BUT the car is pretty foolproof in the corners, it just pulls the car through a corner with much more control than the rwd with the rear engine.

Bo Brammeier

July 12, 2011 at 8:30 PM

Hey Doc. I was also curious what you know about the CPO program. Would you still recommend a PPI if the car is Certified Pre-owned? I am looking at getting something with less than 20k miles on it. Thanks



    July 16, 2011 at 8:55 PM

    CPO protects you from warranty work, but it still will not protect you from the car possibly having previous damage, so a PPI is still a good idea.

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