Porsche 996 Common Problems: What to Watch Out For

In the late 1990s, Porsche completely overhauled their flagship sports car, the 911. Up until this point, the 911 was powered by an air-cooled engine (which means the engine did not have coolant or a radiator, instead relying on airflow, fans, and motor design to keep cool while running). The 996 generation introduced the first water-cooled flat-six in the 911. Produced from 1997 to 2004 (2006 for the Turbo S and GT2), the 996 generation was offered in coupe, cabriolet, naturally aspirated, and turbocharged variants, propelling the 911 into the modern era.

All 911s, even older ones like the 996, are pricey to pick up used. However, with some examples being almost 25 years old, the 996 is one of the more affordable options for second-hand 911s. If you are thinking about buying a used one or just want to stay on top of maintenance on your car, there are a few common issues you should be on the lookout for. In this article, we are going to dive into some of the most common problems with the Porsche 996.

Black 996 Porsche 911 Turbo

Coolant Expansion Tank

Coolant expansion tanks are overflow tanks for excess coolant. They prevent the buildup of excess pressure in the cooling system. When coolant heats up, it expands and can create problems for the cooling system within a car. 

The coolant expansion tanks on 996 Porsches were a particularly weak point of Porsche’s first water-cooled motor. The plastic tank has a tendency to leak and cause loss of coolant and overheating of the engine. If you see any coolant leaks towards the driver’s side exhaust, then the expansion tank could very well be your culprit. 

Coolant expansion tank

IMS Bearing

The Intermediate Shaft (IMS)  bearing in the 996 has been known to fail prematurely, leading to serious engine damage and costly repairs. Poor design is the primary cause of IMS bearing failure. Instead of being lubricated by engine oil, the bearing relied on internally contained grease. The internal grease would eventually wear out, and the bearing would fail. 

Symptoms of an IMS bearing failure can include abnormal engine noises, loss of power, and engine failure. If the IMS bearing fails, it can cause serious damage to the engine, including the pistons, connecting rods, and crankshaft. In some cases, the engine may need to be completely replaced.

If you own a 996 Porsche 911 and are concerned about the IMS bearing, there are several options to address the issue. One option is to have the IMS bearing replaced with an upgraded version that is less prone to failure. Another option is to have the IMS bearing removed and the engine modified to function without it. Both of these options can be expensive and require specialized knowledge and skills.

Many 996 examples have already had this service performed, especially higher mileage ones, but it’s always a good idea to check with the previous owner.

Coolant Pipes (Turbo)

The coolant pipe of a turbocharged car is the pathway for coolant to reach the turbo. The 996 has a turbo coolant pipe strong enough to deal with the pressure, but the epoxy Porsche used for the fittings would often fail and allow massive coolant leaks, which can cause major problems.

A bad turbo coolant pipe can cause a large loss of coolant, which can lead to overheating and extensive engine damage. Proactive replacement of the fittings is a good way to prevent your 996 from encountering the issue and causing further damage, as severe cases can result in complete engine failure (which is not a cheap replacement on a Porsche).

CV Axles

CV (constant velocity) axles are responsible for transferring power from the differential to the wheels and are an important component of the drivetrain. The CV axles on the 996 are prone to failure. 

CV axle failure can be caused by a variety of factors, including wear and tear, damage from road debris, and improper maintenance. If they fail, it can lead to a loss of power and control, making the vehicle unsafe or even impossible to drive.

Symptoms of a failing CV axle may include abnormal noises, vibrations, and difficulty turning. In some cases, the CV axle may completely fail, causing the vehicle to become immobilized.

Proper maintenance and regular inspections can help to prevent issues with the CV axles and other components of the suspension and drivetrain systems. It is important to follow the manufacturer’s recommended maintenance schedule and address any issues as they arise to ensure the safety and reliability of your vehicle.

Wheel Bearings

Wheel bearings are sets of metal ball bearings and rings used to allow the wheels to spin smoothly and efficiently. 996 Porsches with 4WD have the propensity to fail and cause issues in the wheel assembly. 

Bad wheel bearings can cause symptoms such as a grinding noise and disconnected/loose steering feel. It can prove especially unsafe in situations where evasive steering is needed. 

Wheel bearings usually last a long time, but the 4WD system accelerates the process on 996 Porsches. The bearings should be inspected during maintenance and replaced if worn. 


With old cars come old car problems. Many of the 996 models are over 20 years old now, and while their suspension wasn’t prone to rapid wear from the factory, there’s a good chance that your 996 suspension has run its course. 

The springs and dampers are huge wear points in vehicles, as they take the brunt of the force when hitting a bump or pothole. Bushings or other rubber pieces also wear more quickly than other pieces due to their soft and flexible nature. 

If you suspect anything wrong with your suspension, you should inspect or have it inspected ASAP to avoid dangerous issues. Common symptoms include a rough ride, trouble steering, and a feeling of instability from the vehicle at speed or while turning. 

Over Rev Codes

One of the most unique things to look at with the 996 Porsche 911 is the over-rev report. The car takes account of when the engine revolutions (RPMSs) have gone beyond a safe limit and saves it in the vehicle’s computer. 

The report consists of two types of reports. A type 1 event is an ignition at the rev limiter, while a type 2 event is an ignition above the rev limiter. Type 1’s are often due to hard driving and late shifts, while type 2’s are indicative of mis-shifts on the way down. 

The over-rev report is a valuable tool to see how the car has been driven by the previous owner and can affect warranty status if the car should still be covered. Revving beyond redline causes excess wear on the engine. Two identical cars with identical mileage can have two very different reports, which is why the over-rev report is so important for warranty purposes. 

Get your 996 Serviced at Orion Automotive!

Now that you know what to look out for, you can confidently care for your 996 Porsche. If you are looking to buy one second-hand, having a professional look the car over before purchase is a good idea. The Porsche experts at Orion Automotive Services have years of experience and a wealth of knowledge when it comes to these vehicles. Our in-house Porsche Specialist, Tim Pott, will ensure your 996 runs like it did the day it rolled off the lot. Call or schedule an appointment online today!

Book with our certified technicians today!


Book with our certified technicians today!