Here is what LN engineering has to say about IMS bearing failure
What can be done to check for a failing bearing?
First of all, there's no need to loose sleep over IMS failures!
There are a few simple things that can be done next time you're having your Porsche serviced to give you some peace of mind before you take the plunge and have an IMS Retrofit™ kit installed on your car.
Bare minimum, you need add a magnetic drain plug. This makes for easy inspection for IMS debris. Even better, add an IMS Guardian to your MY97-04 car for early detection of IMS bearing issues.
When doing an oil change, check the filter for any debris whatsoever. Same with the magnetic drain plug. Any sparkly metallic (magnetic) debris means you need to stop driving your car and plan to install an IMS Retrofit™. Even if there is only one piece, it's a good bet your bearing is failing.
Here is what IMS bearing debris looks like in the filter. Granted, this is from a full failure, but you can identify the nature of the debris from this photo:
If there is any very small pieces of plastic (bearing seal), that's also a good sign that the bearing is going bad. A failing IMS bearing will expel ferrous material that can be detected by the IMS Guardian to help detect a bearing failure in the earliest stages.
Any oil leaks at the rear of the engine should be checked out immediately - it is common to think you have a RMS leak, but in fact, a failing bearing will allow the IMS flange seal to leak.
Lastly, any technician who knows what a failing water pump or idler belt bearing sounds like should be able to use a stethoscope to listen to the IMS for similar problems from the general vicinity of the IMS bearing.
What can be done to prevent an IMS failure?
There is no quick or easy fix. Like with many aircooled engines, many get torn down and rebuild BEFORE an engine failure so that engines can get upgraded. Short of a pre-emptive rebuild, the best preventative measures that can be taken are to be religious with your maintenance schedule.But keep reading, there's more that you can do.
What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles or 6 months. If you drive short distances frequently or in cold climates, more frequent changes every 3,000 miles or 3 months is advisable.
If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. We use and recommend Motul 8100 5w40, which is an excellent Porsche approved lubricant for both street and track use.
By no means should you use any oil thinner than a 0w40 - do not use 0w30, 5w30, or 10w30 viscosities! Also, use of a low SAPS oil (has less Zn and P) isn't recommended.
Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
Also, make sure you drive your Porsche as it was intended to be driven! We like to see the revs kept above 2,500 rpm - higher rpms provide better protection than lower rpms for the IMS bearing (more on why this is so further down this page). Just make sure you're engine's warmed up first before putting a large load or high rpms on it!
On a new or remanufactured engine built in or after MY06 utilizing the revised M97 IMS, the only "preventative" measure that can be taken short of our Retrofit™ kits is to remove the seal off the front of the IMS bearing, to allow for engine oil to lubricate the bearing. Alternatively, you can repack the bearing with a quality synthetic bearing grease and put a new seal (available from any place that sells bearings). This same technique could be applied also to MY97-05 bearings, if found to be in excellent condition, but by this point, the majority of the labor that is required to do an IMS Retrofit™ would have already been spent, so it's a better value to replace rather than solely inspect and reseal the IMS flange.
With proper lubrication, more frequent oil changes, and spirited driving, longevity of your original IMS can be greatly extended. Our Retrofit™ kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well.