The Porsche 911 is the staple model from the Porsche brand while also being one of the best cars in history. The 911 has a 70+-year-old legacy of being the cutting-edge sports car. Throughout many of its iterations, the 911 still seems to be as superior as it always was.
The 911 recipe consists of a rear-mounted flat 6 engine, rear-wheel drive, and a classic trail-braking driving experience that simply can not be replicated by any other sports car out there. The 911 seems to be a really reliable car which means that most 911 models are dependable and able to last a long time.
However, the 911 is not perfect and the most common and most severe 911 issues are oil leaks, IMS bearing issues, faulty COV solenoids, cylinder scoring, and overheating issues. These may not be the most common 911 issues per se, but are the most common severe issues that do play a major role in long a 911 might last.
All in all, the 911 is a tremendously capable and relatively reliable car that is able to stand the test of time admirably. Even so, you need to maintain it constantly if you want your 911 to hold its value, as well as most 911 models do.
Porsche 911 – Oil leaks
The 911 oil leak issue is a well-known occurrence across most 911 models and generations. The most common places from which the 911 loses oil are the rear main seal, valve covers, spark plug seals, and turbo oil supply line seals. Some of these like the rear main seal leaks need to be addressed immediately as it tends to destroy a manual gearbox in no time.
Because replacing this seal requires you to completely take the engine out, many 911 specialists suggest that you should also replace the clutch while you are at it. Understandably, this does seem like the best course of action, but it does cost a lot of money.
Porsche 911 – IMS bearing issues
Older Porsche 996 and 997 generations are known to suffer from the well-documented IMS-bearing issue that is able to cause all sorts of issues whenever it decides to fail. The IMS bearing is a well-known weak point of these engines which needs to be replaced soon enough if you want to maintain your 911’s value.
It does cost quite a lot of money and is not something you want to fail. As such, be sure to replace it directly at a Porsche dealership or a licensed Porsche specialist. Some say that the IMS problem is not as common as many believe it is, but, it is true that these do drastically affect the resale value of most 996 and 997 models and as such should be replaced.
Porsche 911 – Faulty COV solenoids
All 911 models are known to suffer from potentially faulty COV solenoids. The vacuum solenoid is designed to control the engine vacuum for the engine to affect all the mechanical changes within it. These are typically controlled through the ECU and are controlling many car systems such as exhaust flow, redirecting hot air, and many more.
If the COV solenoids do fail they are likely going to affect the air cleaner flap, exhaust flaps, heater shut off-valve, fuel tank valve vent, transmission and clutch valves, coolant valves, and the tuning flaps. This means that these can destroy many vital car functions and thus should be on the lookout.
Porsche 911 – Cylinder scoring issues
One of the most severe 911 issues ever to be addressed is the dreaded cylinder scoring, or the so-called “Deadly Engine Knocking Noise”. The M96 and the M97 engines are the two most affected by this issue that creates deep gauges in the cylinder liners and can eventually destroy the engine entirely.
Some owners have reported that even some newer 911 models suffer from these issues and that the easiest way to tell is if one exhaust pipe emits black smoke while the other one does not. The root cause of this problem is still not 100% sure which means that fixing this is difficult.
Porsche 911 – Overheating issues
Both the Porsche Boxster and the Porsche 911 are known to sometimes suffer from cracked cylinder liners which lose coolant and therefore overheat the engine. The issue here is that these are really difficult to diagnose without completely removing the engine.
The “easiest” way to tell if your liners are to blame is to start the car up, let it run for at least an hour, and keep a sentient eye on the temperature. Many of these start leaking coolant after the engine has reached a higher operating temperature.
Which Porsche 911 generation is the best?
Both from a technical and value standpoint, the 991 generation is the best. The 991 pre-facelift models are really popular because they still come with naturally aspirated engines while post-facelift 991 models are even more popular because they are overall better versions of the pre-facelift 991.
All in all, no matter which 991 you go for, you are likely going to enjoy it. The 997 is also one of the best 911 generations while the 996 is the most controversial. The current 992 generation is the most advanced 911 of them all, but it is potentially a bit too big and heavy to be able to compete for the best.
Which Porsche 911 generation is worst?
It’s difficult to say that any 911 generation is bad because they are not. However, some generations like the 991 and the 997 are drastically better than the 996. As such, the 996 could potentially be the “worst” 911 model due to many different reasons.
For starters, the egg-plant headlights the 996 comes with are disliked by many. The 996 was also the first water-cooled 911 which was also an issue back at the time. The values of the 996 make it obvious that the 996 is the least favorable 911 ever.
Should I buy a Porsche 911?
Yes, you should. It’s incredibly easy to recommend the 911 as it is such a great car overall. It looks great, it drives great, it is relatively efficient, really reliable and it holds its value admirably. The 911 truly is one of the best cars ever.
Also, the long-lasting 911 legacy has made the 911 a dream car for many generations which means that the 911 legacy is likely to stay strong for many generations to come.