The intermediate shaft bearing, commonly known as an IMS bearing, has a significant failure rate in the Porsche 911 and Porsche Boxster from model years 1997 to 2005. Its structure and design cause the bearing to break early, which causes a catastrophic engine failure.
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How to Determine If Your Porsche IMS Bearing Is at Risk for Failure
From 1999 until 2006, the IMS bearing for these engines underwent numerous design improvements, including both single-row and dual-row bearing designs, but the problem was never sufficiently fixed. The “9A1” engine, the first 911-bound engine to totally do away with the intermediate shaft arrangement in favor of a technology that powers the camshafts straight off the crankshaft, eventually supplanted the M96 and M97 engines. That’s fantastic news if you purchased a 911 from the 2009 model year or later that has the more modern 9A1 engine, but what can you do to avoid IMS bearing failure if you buy a 911 with an M96 or M97 engine? How can you avoid being the victim of a failing IMS bearing if you’re trying to purchase a used 911?
Which Porsche models are susceptible to IMS bearing failure?
All Boxster, Cayman, and 911 vehicles from MY1997 to MY2008, with the exception of Turbo, GT2, and GT3 variants, are susceptible to IMS bearing failure.
But over time, the types of bearings utilized changed, and some of them were more likely to fail than others. According to statistics, the Boxster 986 and 911 models built between model years 2000 and 2005 are the most likely to experience IMS bearing failure, whereas the odds are extremely low for a Boxster 987 or Cayman built after a stronger bearing was introduced in late 2005.
In terms of mileage, there is no clear trend in the failures; some owners were unfortunate enough to encounter IMS issues at less than 20,000 miles, while others assumed they were safe only to have the bearing fail at 130,000 miles. In summary, you should be aware of potential issues if you now own or intend to purchase one of the versions with the weaker bearing that were in use from 2000 until late 2005.
The base engine (3.6) bears the designation “M96,” and depending on your engine number, you may have the smaller IMS or the revised bigger bearing:
Engine (3.6) number M96/05 69507476 has the larger updated IMS bearing, while Engine (3.6) number M96/05 69507475 has the smaller IMS bearing.
The “S” Engine (3.8) is designated “M97” and features a choice of a smaller or bigger upgraded IMS bearing:
Engine (3.8) numbers beginning with M97/01 68509791 have the larger updated IMS bearing, whereas Engine (3.8) numbers up to M97/01 68509790 have the previous IMS bearing.
Does the 996 911 suffer from the Porsche IMS bearing?
Furthermore, according to Rennlist and Pelican Parts forum users, owners of 996 Turbo, GT2 or GT3 models are exempt from Porsche IMS bearing problems. The so-called “Mezger engine” was indeed utilized in these, but it had a modified design that fixed the IMS fault.
The later 997’s IMS problems were also resolved by switching to the Mezger engine, which bears the name of one of Porsche’s illustrious engineers, Hans Mezger. According to Revolution Porsche Specialists, the earlier (2005–2008) 997.1 vehicles still had IMS bearing problems. The company asserts that Porsche 911s manufactured between 2000 and 2005 are the ones that experience IMS bearing failures the most commonly. However, a new engine design for the 2009 997.2 Porsche 911 eliminated the problematic IMS bearing. Any Porsche 911 made in 2009 or after is therefore protected from IMS bearing failure.
Fortunately, even though the IMS problem had an impact on resale values, Porsche 911 sales weren’t greatly harmed. A 996 or 997.1 911 can be an incredibly economical entry into Porsche ownership as long as you keep that in mind.
Ultimate Guide and Frequently Asked Questions for Porsche IMS Bearings
The IMS (middle shaft) of an M96 or M97 engine is supported by a sealed ball bearing. the bearing installed on the intermediate shaft by
Porsche offers an interval, replacement process, or replacement IMS bearing for
It was not able to replace or upgrade the original factory IMS bearing until LN Engineering.
inquiries to find out all there is to know about intermediate shaft bearings
and why the best IMS bearing Retrofit and Solution products are those made by LN Engineering
Paul Kramer’s The Truth About the IMS Bearing
Not to pick on, but the 2009 model year marks a change in that Porsche fully did away with the IMS bearing. Although the IMS bearing was not completely abolished by the 2006-20008 (with the exception of a few very early model years that still had the leftover M96 engine), the failure of the bearing was essentially eradicated. I sincerely doubt that I have read about a single instance of an IMS failure on an M97 motor. It’s interesting to note that IMS bearings have been used in Porsche engines since the 996s. Every 911 from 1964 to 2008 had an IMS bearing, in actuality. Even the cherished Mezger automobiles, such as the Turbos and GT3s, lacked IMS bearings. They simply never fell short. The M96 motors’ failure was mostly the result of poor upkeep. It’s true that poorly designed seals permitted bearing failure in vehicles with little mileage and irregular oil changes. I have never saw an IMS bearing fail in a vehicle that was frequently driven and received regular/appropriate oil maintenance (at least once a year).
With Dwain Dement (the owner of Vision Motorsports), I had a lengthy conversation on the M97, M96, and 2009 direct injection motors. I even went on a tour of his engine manufacturing facility. Each year, Dwain produces around 100 M96 engines as well as almost as many M97 race motors. The IMS bearing is a genuinely trivial problem, which is funny. Any wear issues can be easily detected WELL before catastrophic failure with the right maintenance, etc. However, the majority of individuals simply follow the lore that is widespread online. The casting of the cylinders into the casing is the major problem with M96 motors that is frequently disregarded. They may crack with prolonged use or high mileage. Since their cases are thicker, M97 motors rarely experience cracking problems. According to Dwain, he has never witnessed an M97 motor’s IMS bearing fail. He claimed that the bearing is considerably bigger and stronger.
The M97 IMS failure rate is interestingly close to zero…even with rather subpar care. Additionally, due to how much larger the bearing is than its predecessor, it cannot be replaced until the engine case is opened. Since they are better for higher RPM and a little more durable than direct injection motors in terms of boring to bigger displacement, etc., Dwain employs the M97 motor for the majority of his race car engines. After each race, he conducts an oil study on every M97 engine he supports (well over 20-cars). It’s interesting to note that he rarely observes excessive metal wear until there has been a serious missed shift, which he notes using the Motec(r) system, which is far more accurate than the original DME.
Sorry for the rant, but I’ve written numerous articles about it, visited four engine shops, and spoken with a ton of mechanics and engine builders, including Dwain, Deiter (Andial), Tony Callas, and others. There are numerous misconceptions regarding IMS bearings, etc. I went directly to folks who see these motors and bearings on a daily basis rather than depending on what is written online or in magazines.
Personally, I believe that direct injection motors are given far too much credit. Think about all the troubles that VW and BMW are experiencing with that configuration. All day long, I would choose an M97 engine to save money.
SERPRESULT
Porsche used a dual row intermediate shaft bearing from 1997 to 1999 that has been shown to be just as durable as the larger single row used from models 2006 through 2008.
Exists a 987 IMS issue?
According to our observations, the number of IMS failures has decreased significantly after the M96 (996, 986) engine was updated and replaced with the M97 (997, 987, 987C). This may also be because most of these vehicles are still covered by warranties at dealers, but no issues have been reported to us.
Whether the 2008 Cayman has IMS problems.
The IMS issue only affects vehicles manufactured in 2008 and earlier. Since the 2009 and subsequent engines lack an IMS, they are free of the IMS issue.
997 had IMS problems, right?
It is important to be aware of the problems with the IMS bearings in the 996 and 997 generations if you currently own or are thinking about purchasing a 911 Porsche model or year prior to 2009. It is commonly known that these vehicles’ intermediate shaft (IMS), which operated the engines’ camshafts, had a flaw.
Has the 2007 Boxster got an IMS problem?
They have to get their engine removed right away so the IMS bearing can be replaced. A number of
Failure of these models during routine maintenance on units 987 and 997
models. The grease seal ought to be taken out prior to replacing the clutch or flywheel.
off the bigger, non-serviceable IMS bearing to improve lubrication with engine oil. Keep in mind the
During normal operation, the intermediate shaft is bathed in engine oil, which supplies more than enough oil to cool and lubricate the IMS.
bearing. You can replace the triple lip seal while removing the grease seal from the IMS bearing.
can remove the seal from its groove using a dental pick or a similar tool. Simply remember not to
As soon as you take it out, drop it in the engine. This little YouTube video demonstrates
how to take a ball bearing’s oil seal off
engine damage and timing. The Cayman Register provides a tutorial that walks you through each process of resealing your
The early dual row’s load capacity is equal to that of the larger non-serviceable IMS bearing used in MY06-08 Boxster, Cayman, and 911 engines.
bearing. Since the later MY06-08 IMS bearings and earlier multi row bearings have double the
Once the grease seal has been removed, engine oil will be used to lubricate the bearing.
The 106-08.30 MY06-08 IMS RetrofitTM, when fitted as part of your M96 or M97 engine rebuild, makes
The original, single row bearing is replaced with a ceramic hybrid, dual row bearing in the IMS bearing, making it maintainable in the future without requiring engine disassembly.
bearing. Similar to that, the 106-08.60 IMS Solution offers the only real long-term solution to the IMS issue.
engine. In addition to the IMS Pro Tool Kit, installation requires the IMS Supplemental Toolkit, which comes with six additional tools to help with the MY06-08 IMS installation.