M97 Engine

Problems, tuning, and performance modification guides for Porsche's M97 engine used in the 987 Boxster, 997 911 Carrera, and 987 Cayman.

7 Reasons Why the Porsche 997 is Better Than the 996

April 14, 2022 by porsche 1 Comment

Between the Porsche 996 vs 997, which is the better car? This is a question that many people have asked, and it’s hard to give a definitive answer. Both cars are amazing machines, but they offer different things to their drivers. Some people might prefer the more classic look of the 996, while others might like the newer design of the 997. Ultimately, it comes down to personal preference.

While it does come down to personal preference, there are a few reasons why we prefer the 997 to the 996. Some of it has to do with aesthetics, while other reasons have to do with reliability and the improved IMS bearing.

This article is more of a personal preference and less of a definitive buyers guide. We will write a more in-depth 996 vs. 997 comparison and buyers guide in the near future that will be more objective and detailed than this article.

7 Reasons the Porsche 997 is Better Than the 996

The 996 was produced from 1997 until 2006. The 997 began phasing out the 996 in 2004, although the top-tier trims like the Turbo S, GT2, and GT3 remained under the 996 chassis through 2006.

Comparing the 996 to the 997 is slightly challenging due to the overlap. Additionally, Porsche 997’s used both the M96 and M97 engines. Various trims received the M97 in mid-2005 while the base model stuck with the M96 until 2008. This is an important aspect as there are some common weak points with the M96 like IMS bearings that were addressed and fixed in the M97.

1. The Porsche 997 looks better than the 996

The Porsche 996 is a controversial model in the 911 range. Some love it for its sleek design and powerful engine, while others find fault with its less than luxurious interior and unreliable engine. The 996 interiors fell short of Porsche’s usual high standards, as cost-cutting became the new buzzword.

The 997 was a return to the traditional 911 aesthetic, borrowing some styling cues from the 993. However, it was not as bulky and heavy as the more recent 991s. The interior was completely redesigned with luxury in mind. Even better, 997 interiors have lasted the test of time much better than those of the 996.

The engines in the 997 were also upgraded. Despite some revelations about the M97’s early days, it is not considered to be as unreliable as the M96. However, the DFI engines fitted to second-generation 997s are generally considered to be very reliable. It is important to remember that the 997 was crucial in saving Porsche’s legacy.

2. The 997 is the last remaining mechanical 911

The 997 was equipped with a wide range of electronic driving aids, including VTG, PASM, PTM, and PSM. However, the takeover of the ECU was only evident in succeeding 991s. The most important thing is that electric steering has been added to all 991s, as well as PDK-only transmission and rear axle steer in the new GT or Turbo models. This has greatly improved the image of the 997.

This being said, the 997 still has more of a raw driving feeling compared to the newer Porsche’s of today. However, the 996 is also mechanical and therefore offers a similar feel to the 997. The one difference here is that the 997 is a bit more refined and offers that traditional driving experience while also offering more luxury over the 996.

3. The 997 Mezger Engine is the pinnacle of performance

The GT3 RS 4.0L was released as the final hurrah of the 997 Era and it did not disappoint. This engine produces nearly 500 bhp and has a 3,996cc engine displacement (The RS 4.0 bores are larger). It is truly one of the most beautiful 911s ever made.

the 997 GT3 features the famous “Mezger” engine, which has been refined to offer even more power and performance. This engine is a legacy of Porsche’s racing heritage, and its inclusion in the 997 GT3 ensures that this car will be a force to be reckoned with on the track.

The Mezger engine is actually also included in the Turbo, GT2, and GT3 versions of the 996 in addition to the 997. However, the 997 Mezger engines received a new variable intake system, free flowing intake and exhaust ports, numerous intake cam adjustments, and an increased compression ratio. All of these contributed to more power and performance out of the 997 Mezger compared to the 996.

4. The 997 still offered exclusivity despite being mass-produced

There are more than 30 variants of the 997, so you can choose the one that best suits your needs. However, don’t let this wide selection overwhelm you. Learning about the origins of some variants can help you make a more informed decision. The 911 is one of the most mass-produced cars on the market, but there are still some rare gems to be found. Keep an eye out for these special editions and you’re sure to find the perfect car for you.

The Porsche Turbo S 918 Edition was a limited edition car with only 918 units produced. The Speedster and Sport Classic were both part of the Exclusive group, with 356 and 250 units respectively.

If you want to get your hands on a truly rare 911, then you need to check out the GT2 RS or GT3 RS 4.0. These cars are even more exclusive than the 2.7RS, so you’ll definitely stand out from the crowd if you’re driving one of these bad boys around town.

5. The Porsche 997 is more reliable than the 996

The main reason that the 997 is more reliable is because it predominantly features the M97 engine. While some of the earlier models still use the M96, with the exception of 2004 models, all of these 911’s have the improved IMS bearing.

The M97 does have common problems that include cylinder scoring, cam solenoid failure, and some coolant system related issues. However, when maintained properly the M97 has proved to be a rather reliable engine.

On the other hand, the M96 suffers from not only IMS bearing failure, but also rear main seal oil leaks. Neither of these issues are cheap or friendly to deal with which has given the 996’s and the M96 engine a bad reputation for reliability. While both of these issues are preventable, it costs a few thousand bucks of preventative maintenance to fix these issues.

So while some 997’s do still have the bad-apple M96 engine, the 997 is still considered more reliable since there are a lot more 997’s with the M97 engine.

6) The 997 introduced The first VTG Turbo

The Variable Turbine Geometry feature in the first generation 997 Turbo provides the best of both small and large turbochargers. This is thanks to electrically-operated guide vanes in each turbo that help to achieve optimum gas-flow characteristics at all times.

This resulted in a significant reduction in turbo lag and an expanded range of peak torque. This gave the turbocharged 997 unrelenting, brutal performance throughout the rev range. It transformed the Turbo’s personality. Porsche still uses this technology on the 991 model.

7. The Porsche 997 reached 200mph

The GT2 RS has set a new standard for 911s, beating the 997 GT2 by 1mph three years after it reached a speed of 204mph. No other factory 911 has ever passed the double-ton mark. This is an incredible accomplishment that cements the 997 GT2 RS’s place as one of the greatest sports cars ever made.

While hitting 200+mph is commonplace for Porsche’s of today, this was a cause for celebration back in the day. Additionally, this is a testament to the performance improvements made to the 997 that ultimately make them faster, quicker, and in our opinion, better than the 996.

Conclusion

While there have been many different models and generations of the 911, the 997 generation achieved a perfect blend of modernity and performance which no other 911 series has ever been able to do.

The 997 is newer and received a significant engine upgrade which improved both performance and reliability. Of course, newer cars are faster and offer more modern luxuries, so this might not be a fair reason to explain why the 997 is better. While the 996 offers a rugged and more true or traditional driving experience, the 997 also offers a similar feel while being more luxurious and faster.

Now, should you buy a 997 Carrera or a 996 Carrera? That’s a more challenging subject that is more so budget dependent. For a more in-depth look into the differences between the 997 and the 996 and which is better to purchase, check out our 996 vs 997 buyers guide.

Porsche M96 vs M97 Engine

November 12, 2021 by porsche 2 Comments

The Porsche M96 vs M97 engine differences are actually a hotly debated topic. Which cars use the M97 vs M96 and which engines have the fixed IMS bearing are two of the more controversial subjects. We’ll start off by covering the basics on each of the engines, the differences between the two, reliability & problems, and so on. And then we’ll provide our well-researched opinion on the IMS bearing and for what years it was “fixed”.

Both the M96 and M97 are engine families rather than specific engines. The M96 is the earlier version and was produced from 1996 through model year 2007. In model year 2005 the M97 engine started to make an entrance, phasing out the M96 engine. Additionally, both of these engines are used in the 986 & 987 Boxster’s and 996 & 997 Carerra 911’s. The M97 engine was also put into the 987 Cayman starting in model year 2007.

Porsche M96 Engine

The M96 made its introduction in 1996 as a 2.5L flat-six in the Boxster 986. Throughout its heyday from 1996-2005 it powered the Boxster (986 and 987) and Carrera 911 (996 and 997) vehicles. Impressively enough, the M96 came in 5 different engine sizes. The Porsche Boxtser vehicles had three options, a 2.5L, 2.7L, and 3.2L flat-six engine. The 911’s were equipped with larger 3.2L, 3.4L, and 3.6L flat-six options.

The 2.5L engine was only used from 1997-1999. The engine block was poorly designed and Porsche had some quality control issues in the factory that were leading to cracked cylinder liners. The 2.7L entered in 1999 as a replacement for the 2.5L. The 3.2L option was offered along side these smaller engines for “S” series cars.

The M96 engine receives a lot of criticism due to IMS bearing (intermediate shaft) failures, rear main seal leaks, and cylinder cracking. We’ll discuss these in more depth below.

Porsche M97 Engine

Similar to the M96 engine, the M97 is a 24-valvve water-cooler flat-6. However, while the engine was built off of the same platform as the M96 it features a number of differences that we’ll cover below. The M97 was produced in 2.7L, 3.4L, 3.6L, 3.8L, and 4.0L engine sizes.

Starting in mid-2005 the 997 Carerra S began receiving the M97 engine. Until 2008 the base model 911 Carerra’s used the M96 engine which was eventually phased out in 2009 by the direct-injected MA1 engine. Both the 987 base Boxster and S series had the M96 engine in it until 2007 when they received the newer M97 engine.

The IMS bearing was purportedly fixed for the M97 engine. While failure can still happen and some people still have concerns with the bearing, the failure rate is lower than on the earlier M96 engines. However, M97 IMS bearing failure is a lot more costly as it requires the majority of the engine to be taken apart to get to it.

M96 vs M97 Engine Differences

Although these two engines are very similar in nature there are some important differentiations. We’ll cover the big differences here and then provide some thoughts on the IMS bearings between the two since that is a debated topic.

Increased Displacement

The first and most noticeable difference is that the M97 is a larger engine. While the Boxsters with the M97 still received 2.7L that was used in the base model, the Boxster S 3.2L was increased to a 3.4L, increasing power from 276hp to 291hp. The 2.7L received a small 5hp increase. When the 987 Cayman was released in 2007 it followed the same 2.7L base model and 3.4L S model structure.

For the 911 Carerra, the M97 was also still produced in a 3.6L size, similar to the M96. S models however did receive a larger 3.8L engine. And a 4.0L engine was produced specifically for the GT3 RS 4.0.

Displacement was increased by boring out the cylinders and fitting in larger pistons. Overall, the S models received larger engines while the base models kept the same sizes as the M96 predecessor with only minor power increases.

Adjusted Timing

Aside from the larger displacement, the timing was adjusted to create a smoother torque curve and to handle the power increases caused by the larger engine sizes. However, the intake and exhaust valves remain very similar to the M96 in terns of lift and sizing.

Jet Pump to Mechanical Pump

The brake booster vacuum pump for the M96 was a “suction jet pump”. The details of how jet pumps work are rather technical, so you can read about it here if you’re intrigued. The M97 received an upgraded pump and switched from the suction jet design to a mechanical pump. Avoiding the technical differences, the mechanical pump provides more consistent vacuum supply and therefore a more consistent braking experience, especially when at altitude or when driving aggressively such as on a track.

Electronic Oil Level Sensor

The only way to check oil levels on the M96 engine is by pulling out the dipstick. It had no electronic oil monitoring. The M97 added electronic oil level monitoring so that you could see at all time where oil levels were at, the temperature of the oil, and oil usage. While not a major change oil level monitoring is a good feature to have to prevent serious engine damage from running low on oil. It is also helpful for detecting leaks.

M96/M97 IMS Bearing Upgrade

This topic is where the debate begins. We’ve done a lot of research on IMS bearings and will provide what we believe to be an accurate assessment.

From 1997 until early 2005 the M96 engine used two different IMS bearing designs: the dual-row 5204 bearing and the single-row 6204 bearing. The 5204 bearing was used until early 2000 when it was replaced with the 6204 bearing. The bearing seals on the 5204 bearing deteriorated over time leading to failure. Failure was most commonly associated with age of the bearing and not necessarily mileage on the engine.

Porsche changed the design in early 2000 due to failures and problems with the 5204 bearing. However, the single-row 6204 design is actually considered the least reliable of them all. So, in early 2005 a larger single-row 6305 bearing was introduced. It was bigger and stronger but still not bulletproof, albeit it is considered the strongest of the three.

So, Porsche fixed the majority of the IMS bearing issues in early 2005, although 2005+ IMS bearings are still susceptible to failure. But the number of cases of IMS bearing failures with the 6305 is a lot less than the predecessors.

So, which Porsche engines have the “fixed” IMS bearing?

Since the 6305 bearing wasn’t fitted until some time in the earlier part of 2005, there are some very early M97 engines that still have the bad 6204 bearings. The bearings were also upgraded for the M96 engine at the same time.

So, there are both M96 and M97 engines with old and new bearings on them. Anything with a build date of mid-2005 or later should have the better IMS bearing whereas anything before that will have the worst of the three. It isn’t clear exactly when the switch took place so it is difficult to say whether engines with early 2005 build dates have the new or old bearings.

The downside to the M97 engine’s IMS bearing is that it requires a complete teardown to access it, whereas you only need to remove the flywheel on the M96 engine to access it. While M97 IMS bearing failure is a lot less likely, it is a lot more costly to fix if it does break.

Porsche M96 vs M97 Reliability

The most common M96 engine problems are IMS bearing failure, rear main seal oil leaks, cracked cylinders, and cylinder scoring. Unfortunately, the problems that are common with this engine are on the more expensive side to fix. IMS bearing and rear main seal issues are most common in old cars that haven’t been driven frequently and spent a long time sitting. So while a nice super low mileage M96 might sound tempting, the RMS and IMS are probably ticking time bombs. Fortunately, the IMS bearing can be preventively fixed. We’d give the M96 an average grade for reliability without the IMS fix, and slightly above average when it is fixed.

The vast majority of the M97 engines have the improved IMS bearing which gives this engine a leg up in reliability over the M96. Common M97 engine problems are cylinder scoring, cam solenoid failure, and coolant pipe failure. Most of the reliability issues with the M97 stem from the engine overheating and causing cooling system failures. When properly maintained and cared for, the M97 engine offers solid reliability.

Overall, the M97 is considered to be more reliable than the M96, predominantly since there are a lot less M97’s out there with the old IMS bearings. A 2005+ M96 will be pretty comparable to the M97 in terms of reliability since both with have the stronger and improved bearing.

Porsche’s are unfortunately very expensive to fix. And in terms of reliability costs, the M96 wins since it is a bit cheaper and easier to service compared to the M97. Overall, these are both great engines. But proper maintenance and care is vital for them to remain reliable.

The 4 Most Common Porsche M97 Engine Problems

June 29, 2021 by porsche Leave a Comment

The Porsche M97 engine was the successor to the M96 engine which rolled out for the Boxster’s, Cayman’s, and 911’s from 2005 – 2011. The engine was produced in four different sizes: 2.7L, 3.4L, 3.6L, and 3.8L and was used in Porsche’s from base model Boxsters to the top of the line GT2 RS. The M97 engine is a water-cooled, 24-valve boxer flat-six.

The M97 was retired in most vehicles in 2008, although it lasted in high-performance models until 2011. It was replaced with the direct-injected MA1 / 9A1 engine.

You can check out the most common problems with the M96 engine here.

Porsche’s using the M97 engine

Porsche 987 Boxster:

2007-2008 Boxster Base – 2.7L M97.20 (242hp)
2007-2008 Boxster S – 3.4L M97.21 (291hp)
2008 Boxster S “RS Spyder” – 3.4L M97.22 (299hp)

Porsche 987 Cayman:

2007-2008 Cayman Base – 2.7L M97.20 (242hp)
2006-2008 Cayman S – 3.4L M97.21 (291hp)
2008 Cayman S Sport – 3.4L M97.22 (299hp)

Porsche 997 Carrera 911 S:

2005-2008 911 Coupe S – 3.8L M97.01 (350hp)
2007-2011 911 GT3/RS/RS 4.0
- 3.6L M97.76 (409hp)
- 3.8L M97.77 (449hp)
- 4.0L M97.74 (493hp)
2008-2011 911 GT2/RS – 3.6L M97.70s (523hp)
2007-2009 911 Turbo – 3.6L M97.70 (473hp)

Porsche M96 vs. M97 Engine

The M97 engine is the successor to the M96, and as such was built off-of the M96 engine. Porsche made a handful of material improvements in the M97, but overall, the engines remain very similar in nature and are often subject to a lot of debate on which is better.

Increased Displacement

The top-end M97 engine displacement was upgraded to 3.8L from 3.6L for the 997 Carrera S models. The baseline 997 Carrera’s retained the same 3.6L M96 engine. Porsche increased the displacement by increasing the cylinder bore sizes and fitting them with larger pistons. The increase displacement brought the power up from approximately 316hp to 350hp in S models, and 376hp in S models with the powerkit upgrade.

M97 IMS Bearing Upgrade

Second, the IMS bearing was improved to be bigger and more sturdy. This has eliminated the majority of IMS failure cases although the problem is still hotly debated and discussed on the forums. The IMS bearing received an upgrade in the M96 in 2005 as well as the engine was continued on into the base model 987 and 997 Porsche’s.

Other Upgrades

The two largest improvements were the increased displacement and upgraded IMS bearing. In addition to these changes the M97 also received a timing adjustment allowing for a smoother torque curve and higher power output. The jet pump powering the brake booster vacuum was replaced with a mechanical vacuum pump. Lastly, the M97 received an electronic oil level management system that allowed the car to monitor oil levels while running instead of manually only while the engine is off.

Porsche M97 Engine Problems

IMS Bearing Failure (Not actually common)
Cylinder Scoring
Cam Solenoid Failure
Coolant Pipe Failure

1. M97 IMS Bearing Failure (Not actually common)

You can read all about IMS bearing failures in our recent post on “The 4 Most Common Porsche Boxster 986 Problems”, but we figured we’d briefly touch on it for the M97 engine since it is so frequently brought up. As mentioned above, one of the primary reasons for the M97 engine was to get rid of the IMS problem that blew up with the M96 engine.

Even with the M96 engine, the failure rate of the IMS bearing is roughly estimated to be 5% or less. The reason that this has blown up to be a “common” problem is due to the cost to replace the engine of a Porsche. This is even more so in the case of the M97 engine. The IMS bearing rarely ever fails on the M97 engine – even on cars that aren’t well taken care of; however, it is still possible for it to happen. Due to the large amount of publicity and high repair costs of IMS bearing failures, we have included it, but it is not a common problem. As with the M96 engine, if you want to highly reduce the chances of a bearing failure, drive your Porsche regularly and replace your oil regularly.

M97 IMS Bearing Failure Symptoms

Oil contains metal shavings
Engine makes a knocking noise
Leaking oil from back of engine

There aren’t any significant signs that automatically tell you the IMS bearing will fail, but if you notice any of these symptoms take your car to a mechanic. Catching it early can help you save some of your engine instead of having a full rebuild. IMS bearings also fail at any mileage, some reported as early as 3,000 miles. As stated before, though, this is primarily a problem for the M96 engine and not with the M97 engine.

Porsche IMS Bearing Replacement Options

There isn’t any cheap solution to fixing this problem. Best case scenario, you are replacing a portion of the engine. Worst case scenario, you are doing a full rebuild or getting a new engine. Neither of these options are appealing, so just take proper care of your car. The IMS bearing rarely fails on M97 engines, especially those that get regular oil changes and are regularly driven. Your Porsche is not meant to sit in the garage, so get out and drive it – it’ll be fun and just may save the engine.

2. M97 Cylinder Scoring

Cylinder scoring is the most common issue that results in engine failure for 997’s and the M97 engine. Cylinder scoring is typically the result of a piston striking the side of the cylinder causing grooves in the cylinder wall. This is often caused by poor lubrication.

If you continually make short trips (city driving), there is a greater chance of this occurring as condensation will mix with oil. If your engine never reaches operating temperature the water molecules won’t be burn off.

Cylinder Scoring Symptoms

One exhaust pipe is coated in black soot
The engine making a knocking noise that resembles a hydraulic lift
Increase in oil consumption

Porsche M97 Cylinder Scoring Repair Options

Bore scoring always results in complete engine disassembly, so it is not a cheap problem to fix. There are ways to address the problem for a cheaper cost, but they do not fix the problem. You can have a metal sheet fitted to the problematic cylinder, but this does not fix the bore scoring. It, mostly, temporarily, addresses the problem.

If you are looking for a more permanent fix, LN Engineering will add “nickies” and replace most of the engine parts such as the pistons and rings. This will be a much more expensive process, but it will fix the cylinder scoring and prevent it from happening again.

3. Porsche M97 Coolant Pipe Failure

This primarily occurs for the 997.1 Turbo engine as Porsche fit it with plastic water pipe seals. Over time the seal will degrade and lead to leaking coolant out of the back on a rear-engine car. It starts slow, but eventually can become a big problem as an over-heated engine can cause a lot of problems for Porsche owners.

Coolant Pipe Failure Symptoms

Leaking coolant
High engine temps

Porsche Coolant Pipe Replacement Options

As with most repairs for Porsche’s, this is not a cheap fix. The best option is to upgrade the plastic outlets to metal ones which requires the engine to be removed. You can either upgrade this before any problems occur, or wait until you notice coolant leaking. There is risk in waiting because if you don’t catch the coolant leaking early, you gamble with blowing your water pump or cracking your cylinders which can be more costly than addressing the issue before it becomes a problem.

4. Heavy Clutch – M97 Engine 997.1

This is more so a warning than a large problem with a lot of 997.1 Turbo engines. There are many people out there who report their clutch pedal to be significantly heavier than any other manual car they’ve driven. It can also get worse with added friction from regular wear and tear.

This is primarily an issue for people with knee issues. Some 997.1 owners report only being able to drive for 30 minutes at a time due to the physical stress from operating the clutch. If this pertains to you, then you may want to look at replacing the clutch power spring and/or the slave cylinder.

Porsche Heavy Clutch Symptoms

The clutch is heavy
Difficult to press clutch pedal in
Knee pain after long drives

Heavy Clutch Replacement Options

The clutch isn’t going to weigh the same for every 997, so if you have knee problems or other physical limitations, drive the car and feel the weight before purchasing it. However, if it’s too late for that or you just NEED that Porsche, there are options that can help.

First, try replacing the power clutch spring. It’s a relatively cheap part and can be a quick DIY. If this doesn’t help, replacing the slave cylinder can reduce the pressure but will be more costly than changing out a simple spring. If neither of these options are feasible and you aren’t a manual snob, your best option may be to switch to a PDK (Porsche dual-clutch), or an automatic transmission.

Porsche M97 Engine Reliability

The M97 engine seen in 997’s and 987’s is, in our opinion, a great engine IF you take proper care of it AND if you have the knowledge and resources to either make a few small upgrades, or fix minor issues before they come major ones. The major issues we see from M97 engines start as small issues with the coolant system and with the oil and can be prevented, or the chances significantly decreased, with proper maintenance.

Regularly change your oil, keep an eye on coolant and oil levels and always be aware of any leaks. Drive your Porsche regularly, and let your engine get to operating temperature frequently. Doing things as small as this will help your Porsche run at a high level for a long time. This is especially important if you don’t have the finances or aren’t willing to spend the money on upgrades.