Following the release of the IMS Retrofit by LN Engineering in 2008, Porsche introduced their own IMS bearing replacement in 2017 using a sealed ceramic hybrid ball bearing.
In This Article...
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?
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.
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.
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.
Do Porsche Boxsters have problems with IMS bearings?
With the exception of the Turbo, GT2 and GT3 models, which continued to employ the air-cooled type shaft, all water-cooled 911s, Boxsters, and Caymans from 1997 through 2008 are susceptible to IMS bearing failure.
Porsche modified the bearing type numerous times during the production of these vehicles, first with a dual row bearing from 1997 to 2000 (with minor failure), then switching to a single row bearing from 2001 to 2005. (reports indicate this single row bearing as being the most liable to failure). A larger single row bearing with increased load capabilities was utilized in the following 997 and 987 Boxster and Cayman models, and it turned out to be much more reliable. View the Costs of Replacing IMS Bearings
Should my IMS bearing be replaced?
Any IMS bearing replacement is meant to be installed as a proactive step in routine maintenance and preventative care. The replacement of the intermediate shaft bearing is no longer an option once an engine has failed.
What year Porsches experience IMS issues?
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 build and design cause the bearing to prematurely fail, which causes a catastrophic engine failure.
When did Porsche experience engine issues?
The dreaded intermediate shaft (IMS) bearing failure is the most noticeable and well-publicized problem you’ll encounter on the used market. An IMS bearing failure can result in a loss of the engine timing, which would completely destroy the engine. A Porsche engine replacement is not inexpensive, as you might expect.
The M96 and M97 flat six-cylinder engines used in 911s, Boxsters, and Caymans between 1997 and 2008 frequently experience IMS bearing failure.
However, the 996-era Porsche 911s and 986 Boxsters experienced the most significant IMS bearing issues up to 2006. Despite the significantly lower IMS bearing failure rate in the later year samples, it is still feasible.
Before buying a car, it’s crucial to check the VIN and service records. It is best to budget for an urgent replacement of the IMS bearing if you locate a car in this time frame that you are interested in purchasing. It might cost up to $2,500 to have an IMS bearing replaced by a skilled mechanic.
The cost of replacing an engine, though, can be more than triple that. As a result, it is imperative to replace the bearing before anything else.
You would be hard-pressed to identify any significant failure areas of Porsche flat engines if the age of IMS bearing problems were excluded. Given their great performance, Porsche engines are known to be remarkably durable whether they are new or old.
Some more recent models hardly ever have “bore score,” which is the engine cylinder walls scraping together as a result of inadequate lubrication.
However, if a Porsche has been well maintained, you won’t likely encounter any significant problems.
Has the 2007 Cayman experienced IMS issues?
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.
Has the 2006 Boxster IMS issues?
The intermediate shaft on Porsche 987 Boxster, Cayman, and 997 911 engines was revised for model years 2006 through 2008.
, and a bigger 6305 bearing was employed. However, Porsche used a larger IMS bearing.
is larger than the IMS flange housing bore in M96 and M97 engines produced in and after the 2006 model year, making it impossible to replace this bearing without completely disassembling the engine.
Additionally, this indicates that Porsche will produce and market new engines for the Boxster, Cayman,
and 911 engines will feature the larger non-serviceable IMS starting with the 2006 model year or later.
What year of the Boxster does not experience IMS issues?
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
Why does the Porsche bore score?
The main factor for wear or bore scoring is a lack of cylinder and piston lubrication. All street-legal Porsches require 91 octane gasoline as the minimum grade.