Many of us dream of some day owning a Porsche 911. The likelihood of actually owning a 911 may strongly depend on the market and at the time of this writing, by far the most affordable is the 996 generation. These are the 911’s produced from 1999 to early 2005. It isn’t unheard of for people to pick up a higher mileage albeit fair condition Porsche 911’s of this generation for as little as $10,000. If you fire up Auto Trader, Cars.com or your favorite automotive classifieds you’ll be greeted to a plethora for under $20k. But you might not want any of those. You’ll want to read this before buying a Porsche 911 of the 996 generation and here’s why.
Out With The Old, In With The New Problems
The release of the 996 generation in 1999 brought about many firsts. The new chassis was larger than the outgoing 993 and the interior design was completely new. Everything was all-new in-fact and even though sacrifices had been made in manufacturing to reduce costs, for the 1999 model year, the Porsche 911 Carrera had never been better.
The most notable feature of the 996 models, besides no cup holders, is the standard-option ticking time bomb better known as the M96 and M97 engine. The Porsche community will tell you that only 2% of these engines grenade each year. But let’s do a little math. Multiply that number by 15 years and now we see that a 1999 911 Carrera that has yet to fail has an exponentially greater probability of failing during your ownership. Time to rethink the value proposition.
So what is it about the M96 and M97 engines that fail and what can be done about it? The reason the engines found in the 1999 to 2008 (yup, even up through half of the 997 generation) Porsche 911’s and Boxster’s fail is due to the bearing design holding the intermediate shaft in to place. What is the intermediate shaft?
The intermediate shaft (or IMS) itself is pictured and it’s primary job is to drive the engine’s overhead camshafts via chain sprockets located at both ends. The front sprocket spins the camshaft used for cylinders 4, 5 and 6 while the rear sprocket spins the camshaft for cylinders 1, 2 and 4.
The IMS itself is nothing new to Porsche. It was used in previous generations without so much as a hiccup. But those older engines were air cooled. The 996 Porsche 911 was the first to have a water cooled engine and the design of this engine did not include the oil passages on the flywheel-side that previously lubricated the IMS bearings. The new water-cooled M96 and M97 engines instead used a sealed roller bearing. Porsche switched up the design from a dual row to single row bearing but the failures continued. These were catastrophic engine failures that required and entire engine replacement. A replacement M96 (with the same IMS bearing design) could be north of $10,000. Now the time bomb simply resets. Still excited to own your slice of Porsche history?
Luckily there is a fix. If you find yourself the lucky owner of a Porsche 996, find an aftermarket bearing solution like the dual row design from LN Engineering. It may run you $2,000 for the update but with it comes $8,000 worth of peace of mind. Now you’ve defused the time bomb and have a reliable Porsche 911. No more sweating.
And for clarification, the IMS bearing failures applies to all water-cooled Porsche Boxsters and 911 Carrera’s from 1999 to 2004. A bearing update was made for the 997 generation in 2005 that significantly reduced the occurrence of bearing failures but did not eradicate them. Safest bet is to purchase a 2009 or newer 911 with the updated and more powerful engine.
The Other 996 Option
If a normal Carrera isn’t enough for you, there’s always the 911 Turbo, GT2 and GT3 models. Regardless of which you choose, 60 MPH will flash by in less than 5 seconds. The interior included all of the creature comforts that could be had in a Porsche 911 of those years and with power being put to the pavement by all four tires in the Turbo model, a premium 911 could also be a true year-rounder.
The Porsche 911 GT3 on the other hand is a stripped down lightweight racing machine with a factory roll-bar and hugely bolsters race seats. The suspension is way too firm to pull daily driver duty and the tires way too slick to be driven in anything more than summer months.
Both the Porsche 911 Turbo, GT2 and GT3 variants also use what the Porsche community call the Metzger engine. The Metzger-designed engine found in the 911 GT2 and GT3 is an entirely different animal from those in all other 911s, Boxsters and Caymans – cars much cheaper to manufacture. These engines use an aluminum crankcase, the same found in the air-cooled 911, with it’s true dry sump oiling system. The six separate individual Nikasil lined cylinders in this engine are covered with two separately installed water jackets each covering a bank of 3 cylinders on each side of the engine, thus adding water cooling to a crankcase originally designed for air-cooled cylinders (the normal 996 Carrera engine has the cylinders and water jackets cast together with the crankcase).
The Metzger engine design has found its way through the decades, winning Le Mans in 1998 and has survived to see it’s place all the way up to the current day GT3 RS 4.0 because it is nearly indestructible. These are truly well oiled machines that do not suffer from the same intermediate shaft bearing failures as non-GT2/GT3 911 vehicles.
All that performance and reliability comes at a cost. A 1999 Porsche 911 GT3 should still fetch over $50,000.