Purchasing a Porsche 996?
Buying or owning a Porsche all starts with a dream. For most of us, that dream starts in our early childhood years; and if you are like most of us, before you make any major purchase, such as a 911, you are going to thoroughly research any major purchase. I am writing this to help you make an educated decision on your purchase and what to expect if you are considering the cheapest 911 model - the 996 generation. I owned a 2001 Porsche Carrera 4 (996) for approximately 5 years. I bought it sight unseen off of Ebay. Yes, I took a leap of faith. Purchasing any car off the internet is a gamble. So why did I do it? I had several things going for me that gave me confidence in making this purchase. The first, and probably most important, was the fact that the current owner bought the car Certified Pre-Owned (CPO) from the Porsche Dealership in Naples, Fl, six months prior to me buying it from him . Plus, the owner paid $39,900.00 for the car and I bought it for 24,000.00. The owner wanted to buy his friends Ferrari 360 and needed to sell the 996 immediately, which is why I got such a good deal on the car. Now let's look at and discuss the major reasons why people do not like or trust the 996. First, the Intermediate Shaft bearing, aka IMS bearings; second, the transition from air-cooled to water-cooled; and lastly, the egg-shaped headlights, which went away from the traditional round headlights that was on all the previous generations. The most well-known problem and the one that we will focus on is the 996's Intermediate shaft bearings (IMS bearings). What is the IMS bearing and what does it do? As I mentioned before, Porsche transitioned from air-cooled to water-cooled engines, and in doing so, Porsche had to recreate different parts of the engine; one part of the new design was the intermediate shaft bearing (IMS - see diagram below), which linked the engine's crankshaft with its camshaft via chains.
The IMS bearings allowed the crankshaft to run the camshaft, which would give the chain a longer lifespan. In addition, it ran the engine's oil pump. On a side note, many engines have these shafts, including previous air-cooled 911s.
The problem is, the IMS had a design flaw. Although the IMS bearings runs the oil pump, there wasn't any oil going into the bearings itself to lubricate it, which means it had to rely on its own internal grease for lubrication. Over a period of time, the grease would break down and wear away, which would cause the part to fail. In that scenario, if you didn't catch it immediately, you would be buying a new engine, which is close to $20,000.00.
Today, there are several companies that have replacement parts that can permanently fix the IMS problem; including, but not limited to the following:
LN Engineering: https://lnengineering.com/products/the-definitive-guide-and-faq-for-porsche-ims-bearings/ims-retrofit.html
TuneRS Motorsports: https://tunersmotorsports.com/trs-development/ims-bearing-direct-oil-feed/
Pelican Parts: https://www.pelicanparts.com/More_Info/100124150.htm?pn=10-0124-150-M835&SVSVSI=0907&DID=2114
IMS Retrofit: https://imsretrofit.com/ims-101/
How to determine if your car's IMS is at the point of failure? There are several ways to determine it, if you have a small oil leak in the rear of your car; or when you change the oil, there is metal debris in the oil filter or in the oil itself; and if you are a mechanic, you can remove the IMS cover and see if it is loose. If you are intimate with your car, you can also and hear it, a failed IMS bearing will make some strange noises, such as a rattling sound or vibration during a cold-start. The good news is, you can detect it before it blows your engine.
If you are in the market for a 996, does the IMS bearing affect every 996? The answer is NO, it does not. From what I researched, it affects very few of them actually. Doug Demuro claims that approximately 5% of 996s will reach the IMS failure point (https://www.youtube.com/watch?v=Rr2dzAZEhk4), while the Porsche dealerships will claim that it is less than 1%. The highest statistic that I seen was 7%. Let's look at the highest stat, 7%, which is still a pretty low number if you think about it.
As for the 996 Turbos, from what I researched, the 996 Turbos do NOT/NOT have to worry about an IMS failure. The Turbos used the Mezger engine, which was a different design that eliminated this flaw.
Why does it affect only 7% or less? The owner/driver determines that. Based on my research, if you actually drive the car, and I mean above 4,000 RPMs, than that is when the IMS bearings will spin and grease itself and keep it well lubricated. If the car sits in the garage, or never goes above 3,000 RPMs then the grease inside the IMS shaft will not spin and rotate and eventually dry up leading to failure. So when considering buying a 996, a higher mileage model might not be a bad thing to consider, or buying it from someone who actually drives the car.
I owned my 996 for 5 years and never had an issue or replaced my IMS bearings. After doing my research, I knew that I would "drive" the car and push those RPMs above 4,000 on a weekly basis. I bought the car with 48,000 miles on it, traded it in it five-years later with 66,000 miles on it. My original purchase price was 24,000 and I traded it five-years later for 27,000.00. Yes, I actually made 3,000.00 off the car - Porsches, for the most part, hold their value really well.
This is a picture of my 996 (my first Porsche):
