The Intermediate Shaft Bearing (IMS) failure is a common problem among many Porsche models including the 911, Boxster, Cayman, Cayenne, and Panamera. Many owners are uncertain about what causes IMS bearing failures. This specific issue, which is expensive to repair, can be prevented with basic maintenance and inspections.
The IMS Bearing
The intermediate shaft bearing is a dual-row ball bearing located behind the timing chain cover. The IMS bearing helps turn the camshafts by spinning off of input from the crankshaft.
When oil pressure drops due to a lack of lubrication or excessive heat build-up, the bearing can fail. If this occurs while you are driving at highway speeds, your car will immediately go into limp mode, and you will no longer be able to accelerate or maintain speed. This will force you to pull over on the side of the road to try to prevent your engine from overheating and seizing up.
Causes of IMS Bearing Failure
Here are the most common reasons of an IMS bearing failure:
- Excessive Heat: Porsche IMS bearings are not designed to withstand extreme heat. When they are exposed to high temperatures, they start to expand and may even swell up. When this happens, they cannot spin freely around the shaft, which can cause them to seize up or lock in place. If this occurs while you are driving, it can cause a lot of damage to your engine and transmission as well as other components throughout your vehicle's drivetrain system.
- Oil Starvation: Oil starvation is basically just a lack of oil to the bearing. There are several reasons why this happens. The main reason is that the oil supply is not adequate, or at least it wasn't designed to be sufficient for the loads placed on it by the IMS. Another common reason for oil starvation is a faulty oil pump or pick-up tube.
- Oil Breakdown: Oil breakdown is a situation where the engine oil deteriorates because of heat and constant use. This can happen if you keep using the same oil for too long without changing it, or if you're just driving your car hard all of the time. This can also happen when you use a low-quality synthetic oil that's not designed to withstand high temperatures and extreme conditions like racing or hard driving on track days.
- Contaminated Oil: Contaminated engine oil can cause wear on any part of an engine, and it's no different with the IMS bearing. The most common contaminants are coolant and fuel from leaking intake manifolds and head gaskets. Other contaminants include dirt, sand, and even metal particles from inside the engine itself.
- Assembly Faults: When a Porsche is manufactured, there are numerous checks and balances in place to ensure that the assembly process is done perfectly. All components must be installed in the correct order and the proper torque applied to fasteners. This is particularly important when installing the intermediate shaft bearing cage, which must be installed with a special tool to ensure it is seated properly on the crankshaft shoulder. If this step is missed or not performed correctly, the bearing will move back and forth on the crankshaft as engine RPM increases or decreases, resulting in a rapid failure of the bearing.
Tips to Deal with IMS Bearing Failure
Replace your oil filter and change your oil at least every 5000 miles. Your oil filter should be replaced every 30,000 miles on average. Get regular inspections of your IMS bearing at these intervals. Have this checked at least one time per year, especially when your Porsche has higher mileage. Always check for any signs of metal shavings in the oil which would indicate that there is something wrong with the bearing. If there are metal shavings present, have a mechanic take a look at it immediately.
What to Do When Your Porsche's IMS Bearing Fails
At Royalty Auto Service, we take care of your car as if it was our own, with a commitment to honest and friendly customer service. Our hands-on approach has helped make us the go-to shop for all auto maintenance and repairs in Amelia Island, Brunswick, Kingsland, King Bay Base, Woodbine, Yulee, and St Marys, GA.
Our team at Royalty Auto Service is well-equipped to service luxury European models like your Porsche. Whether it’s emergency repairs or standard service, our friendly staff is here to help. Please call us at 912-576-2886 or visit our shop today to learn more or to schedule an appointment.
* Porsche 911 Car image credit goes to:kenmo.