IMS Bearing

what is the ims bearing?

understanding the ims bearing issue

The Intermediate Shaft (IMS) Bearing is a critical component in the Porsche’s M96 (features in this car) and M97 engines, found in Carrera models from 1997 to 2008. The bearing supports the intermediate shaft, which drives the camshafts, and if it fails, it can lead to catastrophic engine failure.

why is the bearing a concern?

The failure of the seals on the OEM IMS bearings in Porsche M96 and M97 engines is a key factor to the bearing degradation and eventual failure. Here’s what happens:

  1. Heat and Age-Related Degradation

    • The IMS bearing is housed inside the engine, where it is exposed to high temperatures. Over time, the heat causes the rubber seals on the bearing to become brittle, crack, and degrade, allowing the protective grease to escape the bearing.

  2. Inadequate Lubrication Design

    • The factory IMS bearing is a sealed, grease-packed bearing, meaning it does not receive constant lubrication from the engine oil like other internal components. When the seal fails, the grease inside can escape, leaving the bearing dry and vulnerable to excessive wear.

  3. Engine Oil Contamination

    • Once the grease is displaced, engine oil can enter into the bearing. However, engine oil alone is not sufficient to properly lubricate the bearing because it was designed to function with grease. The result is metal-on-metal contact, accelerating wear and eventual failure.

  4. Bearing Load and Stress

    • The IMS bearing is subjected to continuous rotational stress. As the bearing wears down and loses lubrication, the metal surfaces begin to break down, creating metal shavings that can circulate through the engine, leading to catastrophic engine failure.

  5. Corrosion from Moisture Intrusion

    • When a car sits for extended periods, condensation and moisture can accumulate inside the engine, further breaking down the bearing grease and accelerating wear on the bearing surfaces.

failure rates

  • 1997-1999 (Dual-Row Bearing - Early M96 Engines

    • Failure Rate: Estimated at 1% or less

    • These engines used a more robust dual-row bearing which has a much lower failure rate than later versions.

  • 2000-2005 (Single-Row Bearing - Late M96 & Early M97 Engines)

    • Failure Rate: Estimated at 8%-10%

    • The switch to a single-row bearing in 2000 made the IMS bearing more prone to failure, particularly in the 2000-2005 models.

    • This particular car has a dual-row IMS bearing, which appeared in some vehicles as they ran down the inventory of dual-row bearings. This is VERY good news for this particular car.

  • 2006-2008 (Larger Non-Serviceable Bearing - Late M97 Engines)

    • Failure Rate: Much lower, but still a risk.

    • Porsche redesigned the IMS bearing, making it non-serviceable without engine disassembly. Failures are rare but still possible.

Factors that increase ims faillure risk

  • Infrequent Driving: Bearings fail more often in low-mileage cars that sit for long periods. These cars are designed and meant to be driven.

  • Extended Oil Change Intervals: Dirty oil can accelerate bearing wear. The oil in this car is changed every 3,000 miles or sooner with Mobile One synthetic oil, which is the recommended oil by Porsche.

  • Lack of Preemptive Replacement: Cars still running the original bearing (especially in the 2000-2005 range) are at a higher risk. Regardless of playing the odds, the IMS bearing is a wearable component of the car and should be replaced at some point, so you are money ahead if you purchase a 911 with an upgraded IMS bearing and have peace of mind day one!

The good news - this porsche has had the ims bearing replaced!

To eliminate this concern, this 911 has already had the IMS bearing replaced with an upgraded solution, ensuring reliability and longevity. This protection upgrade provides peach of mind, eliminating one of the most well-known concerns with these engines.

what upgraded ims bearing does this porsche have

It was an easy decision; my Porsche mechanic highly recommended the IMS Direct Oil Feed (DOF)® bearing upgrade. I did some of my own research and was in agreement. TuneRS was familiar with the issue of the failing IMS bearings and discovered that the two largest contributing factors were lack of lubrication and excessive heat. So, they tackled the issue at the source of the problem. Their patented Direct Oil Feed (DOF)® give the bearing a continuous oil bath that assures proper lubrication at any RPM. Their testing on the racetrack during the 48-Hour Sebring PCA club race event showed that the oil fed to the ball bearings had cooled the bearing temperatures on an average of 30+ degrees Fahrenheit.

You are probably asking, how does the TuneRS DOF work? TuneRS Direct Oil Feed (DOF)® upgrade uses a patented custom-made Intermediate Shaft Flange that enables a direct flow of filtered and cooled motor oil directly to the open end of the Intermediate Shaft Bearing. The bearing receives oil fed by a custom oil line run from the positive oil pressure feed located on the engine valve cover directly to the custom designed Intermediate Shaft Flange. This oil comes directly after the oil-cooler thus delivering a cool flow of oil. This much needed lubrication and cooling has direct access to the ball bearings as the outer seal on the bearing is removed to allow oil flow. Therefore, providing the bearing with continuous flow of filtered engine oil for constant lubrication and cooling.

how much oil is to the ims bearing & what temperaturs?

  • Test data performed on a 2002 Porsche 911 3.6L Engine

  • Mileage: 57,542

  • Outside Ambient Temperature: 88°F

  • Outside Relative Humidity: 64%