What Should a Rebuilt Porsche Engine Really Include?

Shopping for a rebuilt Porsche engine can be confusing because the term “rebuilt” does not always mean the same thing from one shop to another. One engine may be advertised as rebuilt because it was disassembled, cleaned, fitted with new seals and gaskets, and put back together. Another may be fully inspected, measured, machined, reconditioned, upgraded, balanced, blueprinted, and assembled using proven solutions to correct known Porsche engine failure points.

Both may be called “rebuilt,” but they are not the same product.

This difference is especially important for Porsche Boxster, Cayman, 996, and 997 owners with M96 and M97 engines. These engines have well-known failure modes, including bore scoring, cracked cylinders, IMS bearing issues, oiling concerns, timing chain wear, cylinder head problems, bearing wear, and debris contamination. A proper Porsche engine rebuild should address the entire engine system, not simply replace the obvious failed part.

Flat 6 Innovations has spent more than 25 years focused on Porsche engine reconstruction, development, and failure analysis. Their approach is based on the idea that a Porsche engine should be rebuilt as a complete, engineered system, not assembled as a collection of reused parts.

Read Flat 6 Innovations’ definition of a rebuilt engine

What Does “Rebuilt Porsche Engine” Actually Mean?

At its most basic level, a rebuilt engine is one that has been disassembled, inspected, cleaned, repaired or machined as needed, and then reassembled with the goal of restoring proper function and reliability. That definition sounds straightforward, but the problem is that the standard can vary dramatically from one shop to another.

Technically, an engine could be taken apart, cleaned, fitted with a few new parts, and reassembled. That may allow someone to call it rebuilt. But it does not necessarily mean the crankcase was properly reconditioned, the cylinder heads were rebuilt correctly, the crankshaft was inspected, the rotating assembly was balanced, the IMS was addressed, bearing clearances were set, or the original failure mode was corrected.

That is why the word “rebuilt” can be misleading. Porsche owners should not compare engine rebuilds by price alone. They should compare what is actually being done.

Rebuilt, Repaired, Remanufactured, and Reconstructed Are Not the Same

Before choosing a shop, it helps to understand the difference between common terms.

A repaired engine may only receive the minimum work needed to make it run again. This could mean replacing a damaged component without correcting the root cause of the failure.

A rebuilt engine can vary widely. Some rebuilds include extensive measurement, machining, and replacement of worn components. Others may reuse many original parts with little more than new seals, gaskets, and bearings.

A remanufactured engine is typically rebuilt to a more standardized specification, often with more wearable components replaced and a goal of returning the engine closer to original condition.

A reconstructed engine goes further. This is the term Flat 6 Innovations uses because their goal is not simply to return the engine to its original state. Their process is designed to correct known design flaws, upgrade key components, improve reliability, and build an engine that is better suited for long-term use.

Why Rebuilt Porsche Engine Prices Vary So Much

One of the biggest questions Porsche owners ask is why one shop can advertise a rebuilt engine for far less than another. The answer usually comes down to what is included, what is reused, what is skipped, and how much actual reconditioning is performed.

A lower-cost rebuild may reuse most of the original internal parts. It may not include full crankcase reconditioning, cylinder repair, cylinder head rebuilding, IMS shaft work, upgraded fasteners, balancing, blueprinting, or extensive cleaning. It may also avoid replacing expensive components unless they are visibly broken.

That can make the initial price look attractive, but it may leave the engine with the same weaknesses that caused the original failure.

Flat 6 Innovations explains that some shops advertise so-called rebuilt engines at prices lower than the cost of a proper engine rebuild kit, before even accounting for the cost of correctly reconditioning major components such as the crankcase, cylinder heads, and intermediate shaft. That price difference is not magic. It usually means parts or processes are being left out.

Read Flat 6 Innovations’ explanation of what parts are required

What a Quality Porsche Engine Rebuild Should Include

A proper Porsche engine rebuild should begin with complete disassembly and failure analysis. The goal is not just to replace damaged parts, but to determine why the engine failed and what must be corrected before the engine goes back together.

At a minimum, a quality Porsche engine rebuild should include:

• Complete engine disassembly
• Thorough cleaning of all components
• Inspection and measurement of all critical parts
• Crankcase inspection and reconditioning where required
• Cylinder bore inspection and repair planning
• Crankshaft inspection for straightness, cracks, and wear
• Connecting rod inspection and reconditioning or replacement
• Measurement of main and rod bearing clearances
• Cylinder head inspection and rebuilding
• Valve guides, valve seats, and valve springs addressed as needed
• IMS shaft inspection and correction where applicable
• IMS bearing solution where applicable
• Timing chains, guides, rails, and tensioners inspected or replaced
• Oil system cleaning and inspection
• Replacement of worn or failure-prone components
• Dynamic balancing of rotating components
• Blueprinted final assembly
• Final testing and break-in guidance

If these processes are not included, the owner should ask why.

Flat 6 Innovations’ Process

Flat 6 Innovations describes its Porsche engine rebuild process as deliberately time-intensive, with quality placed ahead of speed. Their process begins with a comprehensive assessment of the core engine. Engines with catastrophic failures, overheating damage, cracked cylinder heads, connecting rod failures, or crankshaft failures may be disqualified from rebuild eligibility because not every engine core is a suitable foundation.

Before disassembly, engines are inspected for issues such as porous crankcases or rear main seal leaks related to manufacturing defects. During disassembly, each component is examined, photographed, and tagged, even if it will not be reused.

The engine cases are sent to LN Engineering for reconditioning, which can include installing Nickies aluminum nickel-silicon-carbide plated sleeves, resurfacing the deck, and vapor blasting the exterior. The intermediate shaft is checked for runout, the drive sprocket is pinned, and the IMS Solution is installed where applicable.

Cylinder heads are inspected for cracks and defects before complete reconditioning. This can include new guides, new seats, new valve springs, and a precision Serdi multi-angle valve job. Performance builds may also receive extensive cylinder head porting.

Crankshafts are inspected for straightness and cracks, then polished. Damaged crankshafts are replaced rather than relying on oversized bearings that could compromise structural integrity. The crankshaft carrier is inspected and line honed to improve oiling, and rotating components are dynamically balanced.

Before final assembly, components receive ultrasonic cleaning and a denatured alcohol wipe-down. Flat 6 Innovations emphasizes that every component, including new components, is inspected and measured before assembly. The final engine is blueprinted rather than simply assembled.

Read Flat 6 Innovations’ rebuild process overview

Why Parts Selection Matters

A Porsche engine rebuild is only as good as the parts and processes used. Reusing too many original components may keep the price down, but it can also leave the engine with worn or marginal parts that should have been replaced.

Flat 6 Innovations states that it replaces more components with upgraded parts than it retains. Even the components that are reused undergo inspection, measurement, and significant reconditioning.

For M96 and M97 engines, Flat 6 Innovations uses solutions co-developed with LN Engineering, including Nickies sleeves and the IMS Solution. These solutions were developed to address known problems rather than simply restore the engine to its original vulnerable configuration.

That distinction matters. A rebuilt engine that repeats the original design weaknesses may be cheaper, but it may not be the better value.

Why Bore Scoring Must Be Addressed Properly

Bore scoring is one of the most common reasons Porsche owners begin searching for a rebuilt engine. On affected M96 and M97 engines, bore scoring can cause ticking noises, oil consumption, smoke, metal debris, and loss of compression.

A proper rebuild must correct the damaged cylinder surface and the piston/ring system. Simply replacing pistons or installing new rings in damaged cylinders will not solve the problem.

Flat 6 Innovations uses LN Engineering Nickies sleeves as part of its cylinder repair strategy. These aluminum nickel-silicon-carbide plated sleeves provide a durable bore surface and help address one of the most significant failure points in affected Porsche engines.

When comparing engine rebuild quotes, owners should ask exactly how the shop addresses bore scoring. If the answer is vague, the rebuild may not be addressing the root problem.

Why the IMS Solution Matters

IMS bearing issues are another major concern for many Porsche Boxster, Cayman, 996, and 997 owners. A complete rebuild of an applicable M96 or M97 engine should include a serious IMS strategy.

Flat 6 Innovations uses the IMS Solution, co-developed with LN Engineering. Rather than simply installing another sealed ball bearing, the IMS Solution replaces the original bearing approach with a pressure-fed plain bearing system designed as a permanent solution.

During the Flat 6 Innovations process, the intermediate shaft is checked for runout, the drive sprocket is pinned, and the IMS Solution is installed where applicable. This is an example of how a properly reconstructed engine addresses known weaknesses during the rebuild, instead of treating them as optional add-ons.

Why Cylinder Heads Cannot Be Ignored

Cylinder heads are often one of the most expensive and important parts of a proper Porsche engine rebuild. Worn guides, damaged seats, weak springs, cracks, poor sealing, and previous machine work can all affect reliability and performance.

Flat 6 Innovations’ process includes cylinder head inspection and reconditioning. This can involve new valve guides, seats, springs, and a precision Serdi multi-angle valve job. For performance engines, ported cylinder heads are the result of years of flow bench refinement and dyno testing.

A cheaper rebuild may not include this level of cylinder head work. If cylinder heads are reused without proper inspection and reconditioning, the owner may face oil consumption, poor compression, valve train problems, or repeat engine failure.

Why Bigger Does Not Always Mean Better

Increasing displacement can be appealing, but size alone does not determine engine quality. Flat 6 Innovations emphasizes that the complete engine combination matters more than displacement alone.

Their Stage 2 Street and Track Performer engines include more than Nickies cylinder sleeves. These engines may include high-compression forged pistons, custom Total Seal rings, forged connecting rods, ported cylinder heads, upgraded valve seats, guides, valve springs, modified camshaft timing, performance camshafts, upgraded hardware, ARP fasteners, coated bearings, optimized clearances, and internal modifications intended to improve oiling and reduce common failure modes.

A larger-displacement engine that is not properly engineered can be less reliable than a smaller, well-designed combination. The goal is balance: power, torque, drivability, durability, and longevity.

Read Flat 6 Innovations’ explanation of why not all rebuilt engines are created equally

Why Cleaning, Balancing, and Blueprinting Matter

Cleaning, balancing, and blueprinting are often invisible to the customer, but they are essential to engine life.

Cleaning removes oil residue, carbon, abrasive debris, metal particles, and contamination from the engine. This is especially important after failures that produce metal debris.

Balancing reduces vibration and stress on the rotating assembly. A properly balanced rotating assembly can improve smoothness and reduce fatigue on components.

Blueprinting means measuring, verifying, and setting critical clearances and specifications during assembly. It is not enough to assume that new parts are correct. Flat 6 Innovations measures even brand-new components before final assembly.

These steps take time, labor, and expertise. They also help explain why a comprehensive Porsche engine rebuild costs more than a basic reassembly.

Questions to Ask Before Buying a Rebuilt Porsche Engine

Before choosing a Porsche engine rebuilder, owners should ask detailed questions. The goal is not to find the cheapest engine. The goal is to understand what is included.

• What exactly is included in the rebuild?
• What parts are replaced?
• What parts are reused?
• Are reused parts measured and documented?
• How is bore scoring repaired?
• Are the cylinders sleeved, plated, or reused?
• Are the cylinder heads fully reconditioned?
• Are valve guides, seats, and springs replaced?
• Is the crankshaft inspected for straightness and cracks?
• Are bearing clearances measured and adjusted?
• Is the rotating assembly balanced?
• Is the engine blueprinted?
• Is the IMS bearing addressed?
• Is the oiling system inspected and improved?
• Are known Porsche failure modes corrected?
• Is there documentation of the process?
• What break-in procedure is required?
• What support is available after installation?

If a shop cannot clearly answer these questions, the owner may not be comparing equal rebuilds.

Why the Cheapest Rebuild May Cost More

A low advertised rebuild price can be tempting, especially when a Porsche owner is already facing a major repair. But a cheaper rebuild may become much more expensive if it does not correct the original failure, reuses marginal parts, skips proper machining, or omits known upgrades.

If an engine has to be removed, disassembled, and rebuilt again, the owner may pay twice for labor, machining, parts, shipping, fluids, installation, and downtime. Saving money on the front end can quickly become the most expensive option.

That is why Porsche owners should compare the scope of work, not just the final number. A complete reconstruction with upgraded parts, proper machining, and documented processes is not the same as a low-cost reassembly with minimal parts replacement.

The Flat 6 Innovations Difference

Flat 6 Innovations positions its engines as reconstructed rather than merely rebuilt. That distinction reflects the depth of the process: failure analysis, careful core selection, LN Engineering case reconditioning, Nickies sleeves, IMS Solution installation, cylinder head rebuilding, crankshaft inspection, carrier line honing, balancing, blueprinting, upgraded components, and Porsche-specific performance development.

Their work is backed by decades of experience, years of research and development, dyno testing, flow bench refinement, and a focus on known Porsche engine failure modes. For owners of Boxster, Cayman, 996, and 997 models, that experience is the difference between buying a rebuilt engine and investing in a properly engineered Porsche engine.

The Bottom Line

Not all rebuilt Porsche engines are created equally. The word “rebuilt” can mean anything from a basic teardown and reassembly to a fully reconstructed engine with upgraded components, corrected failure points, precision machining, balancing, blueprinting, and documented assembly.

For Porsche owners comparing rebuild options, price should never be the only deciding factor. The real question is what the rebuild includes, what problems are corrected, what parts are replaced, and whether the engine is being built by a shop with deep Porsche-specific experience.

Flat 6 Innovations goes beyond the minimum by treating the engine as a complete system. Their reconstructed Porsche engines are designed to address known weaknesses, improve durability, and deliver the power, drivability, and reliability Porsche owners expect.

Are all rebuilt engines created equally?

What processes should be carried out?

What parts are required?

The definition of a rebuilt engine

Contact Flat 6 Innovations

Porsche IMS Bearing: Why It’s Still a Critical Ownership Issue

The Porsche IMS bearing is one of the most important topics for owners and buyers of water-cooled Porsche models from the late 1990s through the late 2000s. While the issue has been discussed for years, it continues to catch new owners off guard—often because they believe the problem is either rare, already solved, or no longer relevant.

The IMS bearing supports the intermediate shaft that drives the engine’s cam timing. When this bearing fails, the result is frequently catastrophic engine damage. Porsche revised the bearing design multiple times, but none of the factory versions eliminated the underlying risk. As these cars age, the likelihood of failure increases due to time, mileage, and lubricant degradation.

A major source of confusion is the continued use of failure rate statistics from the Eisen class action lawsuit. Those figures were based on data collected many years ago, when the vehicle population was significantly younger. Today’s cars are operating well beyond their original design lifespan, making those numbers increasingly irrelevant.

Another misunderstanding is the belief that an upgraded IMS bearing is permanent. Many replacement bearings still require scheduled replacement. Only pressure-fed plain bearing conversions eliminate the service interval entirely.

For buyers and owners alike, the most important factor is documentation. Knowing whether the IMS bearing has been addressed, how it was addressed, and whether it requires future service is essential to protecting the engine and the investment.

IMS Bearing Replacement Costs: What to Budget and How to Choose Between IMS Retrofit and IMS Solution

If you own a 1997–2008 Porsche Boxster, Cayman, or 911 with an M96/M97 engine, planning for ims bearing replacement costs is smart preventative maintenance. A proactive IMS service typically runs $1,500–$3,000 installed (parts + labor), which is far less than the cost of an engine rebuild after a failure.

Related resources: IMS Bearing Replacement Costs Guide (LN Engineering)  |  IMS Retrofit  |  IMS Solution

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IMS Bearing Replacement Costs (Typical Ranges)

Most owners see totals in this range, depending on model, transmission, shop rate, and bundled services:

Service Package	What’s Included	Typical Installed Cost
IMS Retrofit only	IMS Retrofit kit (ceramic hybrid ball bearing), labor to access and replace	$1,500–$2,300
IMS Retrofit + clutch + RMS	Add clutch components and rear main seal while transmission is out	$1,900–$3,000+
IMS Solution (oil-fed plain bearing)	Permanent, oil-fed plain-bearing kit; similar labor time, higher parts cost	$2,200–$3,500+ (varies by model and add-ons)

Note: Tiptronic/automatic models can add labor; regional shop rates and parts selection also affect totals.

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What Affects IMS Bearing Replacement Costs?

1. Labor time & transmission type – Manual cars typically require transmission removal; some Tiptronic cars may need the engine/trans removed as a unit.
2. Parts choice –
   • IMS Retrofit (ceramic hybrid ball bearing) generally has the lower parts cost but includes a service interval (often 6 years / 75,000 miles).
   • IMS Solution (oil-fed plain bearing) has a higher initial parts cost, but is engineered as a permanent fix with no planned service interval.
3. Bundled “while you’re in there” items – Common add-ons: clutch, RMS, air-oil separator, water pump, dual-mass flywheel (DMF), fluids/filters.
4. Pre-qualification & inspection – Verifies the engine is a good candidate; findings can change scope and cost before work begins.
5. Tools & logistics – Access to the right fixtures and rental tools keeps labor predictable.

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Choosing Between IMS Retrofit and IMS Solution

IMS Retrofit (Service-Interval Approach)

• What it is: A ceramic-hybrid ball-bearing upgrade designed to be oil-lubricated in service.
• Why owners choose it: Lower up-front parts cost; an effective upgrade when paired with a clutch service.
• Service interval: Commonly 6 years / 75,000 miles (confirm for your specific kit).
• Learn more: IMS Retrofit

IMS Solution (Permanent, Oil-Fed Plain Bearing)

• What it is: An oil-fed plain bearing that rides on a pressurized oil film (like crank bearings), eliminating rolling elements.
• Why owners choose it: No planned service interval; engineered for the life of the engine—ideal for long-term ownership.
• Warranty: Limited warranty terms vary by application; review details at the official site.
• Learn more: IMS Solution

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Best Time to Schedule IMS Service

The most cost-effective time for ims bearing replacement is during a clutch or RMS job. With the transmission already out, you avoid duplicate labor and can bundle other preventative items.

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Cost-Saving Tips

• Bundle smart: Combine IMS with clutch and RMS while the transmission is out.
• Confirm your current setup: If the car already has an IMS upgrade, check the install date/mileage and applicable service interval.
• Pre-qualify: A quick inspection prevents installing a new bearing into a compromised engine.

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FAQ: IMS Bearing Replacement Costs

What’s the main cost difference between IMS Retrofit and IMS Solution?

Parts cost is the big swing. IMS Retrofit kits are typically lower priced up front but have a service interval. The IMS Solution kit costs more initially but is designed as a permanent oil-fed fix with no planned interval. Labor time is broadly similar because access steps overlap.

Why do some quotes exceed $3,000?

Higher regional shop rates, extra labor for Tiptronic models, and bundling of clutch/RMS/DMF, etc., can push totals above the usual window—but bundling often saves money over the long term by avoiding duplicate labor.

Do I really need pre-qualification?

Yes. Pre-qualification confirms your engine is a candidate for the work and helps avoid installing new parts into an engine that’s already experiencing damage.

Is waiting OK if my car shows no symptoms?

A clean filter and quiet engine aren’t guarantees. Planning a proactive IMS service—ideally aligned with clutch or RMS work—helps avoid unpredictable and costly failures.

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Bottom Line

Budget $1,500–$3,000 for most ims bearing replacement costs on affected Porsche models. Choose IMS Retrofit for lower up-front parts cost with a planned service interval, or step up to the IMS Solution for a permanent, oil-fed approach with no planned interval. Either strategy is far cheaper—and far less stressful—than a post-failure engine rebuild.

More info: LN Engineering  |  IMS Retrofit  |  IMS Solution

Installing the IMS Solution: A Step-by-Step Guide to the Only Permanent Fix for the Porsche IMS Bearing

When it comes to Porsche engine reliability, few topics spark as much conversation as the intermediate shaft (IMS) bearing. Fortunately, there's one patented, permanent fix: the IMS Solution.

In this comprehensive guide, Jake Raby of Flat 6 Innovations walks viewers through the installation process for the IMS Solution, a retrofit engineered to eliminate IMS bearing failure—a well-known Achilles' heel in Porsche M96 and M97 engines. Based on the video walkthrough and the official 2023 IMS Solution installation manual, here’s everything you need to know.

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✅ Pre-Installation: Critical Qualification Comes First

Before installation begins, pre-qualify the engine to ensure it's a viable candidate:

• Perform a full diagnostic scan (fault codes, camshaft deviation, over-revs)

• Check crankcase vacuum and inspect for debris in the oil, filter, and sump

• Perform a bore scope inspection of cylinder bores

• Never install the IMS Solution in an engine that has suffered a prior IMS failure

🛠️ For full details, read the 11-step IMS Pre-Qualification Procedure in the manual.

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🔧 Step-by-Step IMS Solution Installation Summary

The installation is broken down into a series of chronological, precision-based steps:

1. Remove the Gearbox

Start by pulling the transaxle to gain access to the IMS flange (911 Tiptronic owners will need to remove the engine as well).

2. Set the Engine to TDC

• Rotate the crankshaft clockwise to top dead center (TDC) for Cylinder 1

• Lock the crankshaft with the IMS Pro Toolkit’s locking pin

⚠️ Performing the procedure out of time will result in camshaft timing errors.

3. Secure Camshafts and Remove Chain Tensioners

• Remove bore plugs and lock the right-side camshaft

• Remove all three timing chain tensioners (left, right, and IMS-side)

4. Modify the Crankcase for Oil Feed Line

• Use a drill and handsaw to create an oil feed port

• File the opening to ~20mm to allow fitting of the IMS Solution oil feed fitting

🛠️ This step is critical to enable the oil-fed design of the IMS Solution. The flange serves as a drilling template.

5. Remove the Original IMS Bearing

• Use the IMS Pro Tool to extract the bearing through the center stud

• Clean the intermediate shaft thoroughly

• Install the supplied plug using the provided installation tool

6. Install the IMS Solution Bearing

• Lubricate and tap the bearing into place with a soft-faced hammer

• Place the protective shim and reuse the original snap ring (or spiro-loc if dual row)

7. Install the IMS Solution Flange

• Lubricate the O-ring and bearing surfaces

• Tap the flange in until flush with the crankcase

• Torque flange bolts to 7 ft-lbs and the center nut to 12–20 ft-lbs

8. Spin-On Oil Filter Adapter Installation

• Lubricate and install the adapter with supplied sealant

• Use the provided shim if needed to clock the fitting correctly

• Torque to 18 ft-lbs using a special spanner wrench

9. Install Oil Feed Line and Finalize

• Connect the stainless-steel braided oil line from the filter adapter to the flange

• Tighten both fittings and install a WIX 51348 oil filter

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🛠 Post-Installation Checks & First Start

• Start the engine and run it until the oil light goes out

• Check for any oil leaks

• Verify oil line clearance—especially on vehicles with aftermarket sway bars

• Use Driven DT40 oil for street use, XP9 for track duty

• Change oil every 5,000 miles or 6 months, whichever comes first

🔁 Cycle the ignition 4–5 times to build oil pressure before full engine start.

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Why the IMS Solution Is the Only Permanent Fix

Unlike conventional ceramic hybrid bearing retrofits, the IMS Solution:

• Eliminates the ball bearing entirely

• Is oil-fed for superior lubrication

• Requires no future servicing

• Is the only retrofit protected by three U.S. patents

The IMS Solution is the result of years of development by Jake Raby and Charles Navarro of LN Engineering and has been successfully installed in tens of thousands of vehicles worldwide.

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🔗 Learn More:

• IMS Solution Install Instructions

• Official IMS Solution Product Page

• IMS Solution Certified Installers

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Final Thoughts

Installing the IMS Solution is not just a repair—it’s preventative engineering. Done correctly, it transforms the Porsche M96 or M97 engine into a far more robust, reliable powerplant. As Jake says:

"There’s only one permanent fix for the IMS bearing—and that’s the IMS Solution."

What Porsche Owners Need to Know About the M97 IMS Bearing (2006–2008)

Jake Raby of Flat 6 Innovations, the inventor of the IMS Solution, has spent decades educating Porsche owners on the nuances of intermediate shaft (IMS) bearing failures. In a recent RenVision video, Jake shifts the spotlight to the often misunderstood M97 6305 large single row IMS bearing, used in 2006–2008 Porsche Cayman, Boxster, and 911 models.

This article highlights key takeaways from Jake’s video and explains what every Porsche owner should know if their vehicle is equipped with the M97 bearing.

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What Is the M97 IMS Bearing?

The M97 IMS bearing is a large single-row 6305 bearing introduced in mid-2005 and fitted to all 2006–2008 Porsche 987 (Boxster/Cayman) and 997 (911) models with the M96/97 engine family. It succeeded earlier dual-row and 6204 single-row IMS bearings, which were more prone to failure.

The larger M97 bearing has proven to be highly reliable, with Jake Raby personally having seen only three failures since 2006.

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Why the M97 Bearing Can’t Be Retrofitted (Under Normal Circumstances)

A crucial point often misunderstood: The M97 bearing cannot be removed without full engine disassembly. Unlike earlier IMS bearings that could be accessed through the crankcase's rear service port, the 6305 bearing is physically too large to pass through this port.

Modifying the crankcase to access the M97 bearing is strongly discouraged due to the risk of damaging structural integrity.

🔧 If the engine is apart, the M97 bearing can and should be replaced—preferably with the IMS Solution, a permanent fix developed by Jake Raby and sold by LN Engineering.

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What to Do If Your Porsche Has the M97 Bearing

Jake's advice is straightforward:

• If your engine is together and running well, do not retrofit the M97 bearing.

• If your engine is apart, it makes sense to upgrade the bearing while you’re in there.

LN Engineering offers a ceramic hybrid bearing replacement or the IMS Solution, which replaces the ball bearing entirely with a plain bearing and provides future serviceability via a bushing adapter.

🛠️ Learn more about replacement options here:
👉 M97 IMS Bearing Replacement Guide

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What About 2005 Model Year Vehicles?

The 2005 model year is a gray area. Some engines from 2005 were fitted with the older, failure-prone 6204 single-row bearing, while others received the newer M97 6305 bearing. Unfortunately, VINs and engine numbers cannot reliably tell you which you have.

Jake recommends a visual inspection of the IMS flange bolt:

• 13mm nut = early single row (6204) bearing

• 22mm nut = M97 large bearing (6305)

If you discover a 13mm nut during a clutch job or other gearbox-out service, stop and retrofit the IMS bearing immediately.

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What About Factory Replacement Engines?

Even early Boxsters and 996s (1997–2004) may have M97 bearings if they received factory replacement engines after 2005. Porsche retroactively used the 6305 bearing in replacement engines, regardless of model year.

Some clues:

• Later replacement engines often use inverted Torx fasteners instead of hex head bolts.

• Engine serial numbers marked “M96” may still contain M97 internals.

• Visual inspection remains the only reliable method to confirm.

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Should You Still Be Worried About the M97 Bearing?

While Jake Raby dislikes ball bearings inside engines as a matter of principle, he acknowledges that the M97 IMS bearing is robust and rarely fails. That said, high-mileage or heavily tracked cars may be more vulnerable.

Best practices for owners:

• Change your oil every 6 months or 5,000 miles, whichever comes first.

• Use a quality oil and monitor for early warning signs like unusual noises.

• If the engine ever comes apart, replace the IMS bearing proactively.

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Final Thoughts

Jake Raby’s RenVision video clears up much of the confusion surrounding the M97 IMS bearing. His message is clear: Don't panic if your Porsche has the M97 bearing, but be informed and plan ahead.

If your car is from 2006–2008, rest easier knowing the bearing is strong. If it’s a 2005 model or earlier with a replacement engine, take steps to visually confirm which bearing is present—and only trust direct inspection, not VIN or lawsuit eligibility data.

🔗 Related reading:

• Definitive Guide to M97 IMS Bearings (LN Engineering)

• M96/M97 IMS Bearing Failures and Solutions (Part 1)

• M96/M97 IMS Bearing Failures and Solutions (Part 2)

Two Critical Steps Most People Overlook When Replacing Their IMS Bearing: Pre-Qualification and Installation Registration

When replacing the intermediate shaft (IMS) bearing in your Porsche Boxster, Cayman, or 911, the steps for pre-qualification and registration are essential yet often overlooked. Developed and refined by expert Porsche engine rebuilder, Jake Raby, of Flat 6 Innovations, these steps ensure that the IMS bearing replacement is performed on a healthy engine and that the work is documented for long-term reliability. Here’s an in-depth look at why these steps are crucial and how to complete them effectively.

Step 1: The Pre-Qualification Procedure – Ensuring Engine Readiness

Not every Porsche engine is a suitable candidate for IMS bearing replacement. The pre-qualification procedure, pioneered by Jake Raby and LN Engineering, helps determine if an engine is healthy enough for the IMS bearing replacement. Skipping this step could mean overlooking underlying engine issues that could compromise the new bearing or even lead to severe engine damage.

Here are the essential checks in the pre-qualification process:

• General Engine and Vehicle Health Check: Thoroughly inspect the engine and entire vehicle to identify any potential issues that could complicate the bearing replacement. Flat 6 Innovations emphasizes that IMS bearing replacements should not proceed on engines already showing signs of failure or neglect.

• Detection of Bearing Failure: Engines with IMS bearing failure are unsuitable for replacement, as debris from the failing bearing can spread throughout the engine, creating further issues. In cases of failure, the engine typically needs a complete teardown to address any residual damage.

• Cylinder Bore Scoping: Bore scoring, common in Porsche M96 and M97 engines, should be checked via scoping before the IMS bearing is replaced. Bore scoring could indicate deeper issues that require attention.

• Rear Main Seal Inspection: Some early 996 and Boxster engines suffer from chronic rear main seal leaks due to factory mis-machining. If there’s an existing leak with an updated PTFE Teflon seal in place, measuring the engine for mis-machining is critical before proceeding.

• Camshaft Timing Deviation: In early M96 engines (1997-2002 in Boxster and 1999-2001 in 996 models), wear on the chain ramps for the Variocam can occur at relatively low mileage (50-60k miles). If timing deviations exceed 4.5 degrees, replace the wear pads to prevent further issues.

Flat 6 Innovations has maintained a perfect track record with IMS replacements, thanks to this meticulous approach. Following these steps ensures that the replacement bearing is installed in an engine prepared to support it.

Step 2: Installation Registration – Documenting Your Investment

Once the IMS bearing has been replaced, the next essential step is registering the IMS bearing replacement. Whether you handle the installation yourself or have a professional do it, documenting the replacement properly is vital to maintaining warranty coverage and preserving the long-term health of your engine.

Here’s how to complete this process:

1. Apply the Serial Number Sticker: Inside the IMS Retrofit or IMS Solution kit, you’ll find a registration card and a serial number sticker. Place one of these stickers on the car as proof of the bearing’s installation.

2. Send Back the Original IMS Bearing: To complete your registration and warranty, send the original IMS bearing back to LN Engineering. They inspect and photograph the disassembled bearing to document its condition and check for debris that could indicate prior engine damage. If desired, you can request the bearing back as a keepsake (though disassembled), provided you cover the shipping cost.

3. Online Registration: Go to the IMS registration link provided on the registration card and upload your service invoice, proof of purchase, and any relevant photos from the installation. If a shop performed the replacement, include the shop’s invoice and details confirming that the pre-qualification steps were followed.

4. Final Submission and Record Keeping: Once you’ve completed the online portion, send the original bearing and registration card back. Be sure to include all the necessary information, such as your email address and the IMS serial number sticker, so the team can accurately match the bearing with your car’s records.

After LN Engineering receives your bearing, they inspect it for wear, debris, or any abnormalities. If the bearing meets all standards, they’ll complete the registration process and update their database within 60-90 days. Each bearing inspection and registration is documented with photos of the bearing and a record of its condition.

Why These Steps Matter

The IMS bearing replacement is a preventive, not corrective, measure. Skipping pre-qualification could mean missing critical engine issues that lead to costly repairs. Similarly, failing to register the installation could void the warranty on the replacement bearing, leaving the vehicle unprotected.

Together, the pre-qualification procedure and registration are what ensure the longevity of your investment in IMS bearing replacement. They provide a clear, traceable record of the replacement, backed by the peace of mind that comes with LN Engineering’s attention to detail and dedication to quality.