Stadium Auto ServiceThis vehicle was brought to Stadium Auto Service Porsche specialists with an engine oil leak. Our technician who specializes in repair and service of Porsche vehicles suspected the engine's Intermediate Shaft (IMS) Bearing was starting to fail. This is a common problem for this year and model of Porsche.
Problem
Porsche M96 IMS bearing failure and rear main crankshaft seal oil leak.
1997-2005 Porsche Boxer 986/996 and Porsche 911 with M96 engines have a known problem with the failure of the Intermediate Shaft Bearing. The bearing is simply not strong enough to last the life of the engine. This engine design fault can cause serious engine damage if the bearing is not replaced before the outright bearing failure happens causing serious engine damage.
The problem is the bearing is a sealed unit that is weak and not lubricated by the engine oil. The IMS bearing has a limited life and replacement should be considered a maintenance procedure, similar to an oil change, not something that can wait until the bearing fails before replacing.
We recommended an IMS bearing replacement with an upgraded replacement part to give durability and peace of mind. The recommended service replacement of the upgraded bearing is every 75,000 miles or six years.
It is recommended to replace the rear crankshaft seal when the IMS bearing is replaced. It is also good value to replace the IMS bearing when the rear crankshaft oil seal is replaced.
1999 Porsche 911 with the M96 engine are well known for the failure of the engine's Intermediate Shaft Bearing. The recommended best repair is IMS bearing replacement with a heavy-duty IMS dual row retrofit bearing made by LN Engineering. Image Copyright: Stadium Auto Service 2023.
Tips
If the vehicle has high mileage, or if the clutch is worn or has problems, it is good value to replace the clutch while the transmission and clutch are removed from the vehicle. This saves having to remove the transmission again for a clutch replacement.
The IMS bearing replacement is not a repair to postpone until the bearing fails. If the bearing has reached the point where it has begun to fail and metal particles have entered the engine the engine must be replaced or at least disassembled and inspected for internal damage. A simple, relatively inexpensive bearing replacement has now become a potentially very expensive engine repair or replacement.
Repair
After consulting with the vehicle owner the transmission, clutch, and flywheel were removed to replace the rear crankshaft main seal and IMS bearing. With the transmission out of the vehicle, the technician was able to confirm that the IMS bearing was the original factory-installed bearing. The required pre-qualification inspection was performed and passed inspection.
The bearing was replaced with a heavy-duty LN Engineering dual-row IMS replacement bearing.
With the rear crankshaft seal and IMS bearing replaced we finished assembling the car, performed a test drive, and reinspected the vehicle for quality control.
Replacement Parts
We recommend and use LN Engineering IMS replacement bearings. LN Engineering pioneered the IMS Retrofit procedure with the development of the required tools to remove and change the original Porsche IMS bearing.
Stadium Auto Service is a LN Engineering Porsche IMS bearing Certified Installer. https://imssolution.com/certified-installers/
Pre-Qualification Inspection Procedure
LN Engineering has a required inspection process that is required before their replacement parts can be used. This inspection is required for the LN Engineering warranty. Bottom-line is that it is imperative that ONLY healthy, good running engines be retrofitted. Any engine problems must be addressed prior to performing an IMS Retrofit / IMS Solution installation.
The inspection specified and required by LN engineering for IMS bearing replacement is:
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Check engine computer fault codes with scan tool;
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Verify crankcase pressure to check health of oil separator;
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Remove oil pan and inspect for metal particles from failed bearing;
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Inspect cylinder walls for scoring from the crankcase;
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Cut open and inspect oil filter for metal particles.
If defects are found it is possible we will not be able to perform IMS bearing replacement service.
Full inspection details:
Contact Stadium Auto Service for comprehensive Porsche service and repair in the Ann Arbor, MI area. (734) 369-6787
See our Porsche service repair page for more information about the comprehensive Porsche repair service we provide in Ann Arbor, MI 48103
Porsche Models Susceptible To IMS Bearing Failure
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All 986 Boxster models.
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All 996 models (not including GT and Turbo models)
Cost
IMS Bearing Replacement Cost for Porsche Boxster and Porsche 911, 986, 996.
The cost of IMS bearing replacement for Porsche Boxster and Porsche M96 engine can vary depending on a wide range of factors: manual transmission or Tiptronic transmission; the type of bearing kit you choose; additional problems found during disassembly; and if the bearing is changed at the same time as other repairs are performed. Please contact us and we can provide a detailed estimate for your vehicle.
IMS bearing replacement on automatic Tiptronic transmission cars has a higher cost than with a manual shift transmission car.
There are a number of replacement bearings available with a wide range of costs. If you plan to keep the vehicle for a long time the best value is to use an IMS replacement bearing with pressure oil lubrication. The pressure-lubricated bearings have a higher initial cost but usually never have to be replaced again, compared to the recommended life of 75,000 miles for a sealed, non-pressure-lubricated dual-row IMS bearing.
Option 1 – IMS Bearing Replacement with double-row bearing on Manual transmission or Automatic transmission.
Option 2 – IMS Bearing Replacement with pressure oil fed bearing - a more expensive option but with an infinite life on manual transmission or automatic transmission vehicles.
The lowest IMS bearing replacement cost is when the bearing is changed during a clutch replacement or a rear crankshaft seal replacement. Adding an IMS bearing replacement to the overall job only adds the cost of parts and a small increase in labor cost to install the bearing.
Why Replace Porsche IMS Bearing
If the Porsche Boxster or Porsche 911 996 IMS bearing fails it causes a catastrophic engine failure. The bearing starts to shed metal particles that enter the engine and are circulated by the oil system which quickly destroys the engine. A replacement engine can be as much as the value of the car.
There is controversy regarding whether the IMS bearing should be done as a mileage-related maintenance service, or as a repair when needed. The difficult part is catching the IMS bearing problem before the bearing fails and destroys the engine. It is impossible to predict when the bearing will fail. And the failure can progress very quickly and total failure can happen with little to no warning. The best advice is if the bearing has not been replaced, or you do not know the history of the engine maintenance, the bearing should be replaced as soon as possible.
Before you decide to have an IMS bearing replacement performed it is important to understand the associated costs. Especially the possible cost of waiting too long before replacing the IMS bearing and suffering an engine failure.
We strongly recommend having this work done by a shop that has experience repairing this problem. The consequences of not doing the work correctly can be very costly. Stadium Auto Service is a LN Engineering IMS bearing Certified Installer. Call us to discuss your vehicle, the options available, and the costs involved.
Need Help?
Contact Stadium Auto Service for comprehensive Porsche service and repair advice in the Ann Arbor, MI area.
The transmission is removed to gain access to the rear of the Porsche M96 engine. It is easier to remove the transmission and leave the engine in the vehicle. The clutch and flywheel are also removed to access the rear crankshaft seal and IMS bearing. Image Copyright Stadium Auto Service 2023.
Rear view of the Porsche 911 M96 engine with transmission removed. The rear crankshaft seal oil leak is clearly visible. Image Copyright: Stadium Auto Service 2023.
View of the rear of the Porsche 911 M96 engine with a special tool to remove and install the IMS bearing. Image Copyright: Stadium Auto Service 2023.
Porsche 911 M96 engine with new LN dual row IMS bearing and retainer installed. Image Copyright: Stadium Auto Service 2023.
Porsche M96 IMS dual-row replacement bearing. Image Copyright: Stadium Auto Service 2023.
Porsche M96 engine with the special tool to remove and install crankshaft oil seal. Image Copyright: Stadium Auto Service 2023.
LN Engineering IMS Intermediate Shaft bearing kit for Porsche M96 engine.