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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.

The 4 Most Common Porsche Boxster 986 Problems

June 10, 2021 by porsche Leave a Comment

The first generation 986 Boxster was released in 1996, initially intended to be a successor to the poorly selling 928. The Boxster was designed in conjunction alongside the 996 Carrera and shares many of the same parts and features. Engine design, headlights, interior comments, and the hood/front end are all shared between the 986 and 996.

The 986 Boxster lived on until model year 2005 when it was replaced by the 987 Boxster.

Boxster M96 Engine

Both first gen 986 and second gen 987 Boxsters use the M96 engine. The M96 engine came with 2.5L, 2.7L, and 3.2L displacements.

The M96 engine is a water-cooled, naturally-aspirated flat-6. The Boxster used a mid-engine layout for a lower center of gravity, improved weight distribution, and better handling. The M96 was Porsche’s first water-cooled flat fix engine

2.5L M96 Engine

The 2.5 M96 (known as the M96.20) was used from 1997 until 1999. It produced approximately 200hp and 180 lb-ft. of torque. The initial 2.5 engine had a poorly designed engine block which would cause the cylinder liners to crack. Additionally, the cylinder cracks affected the cooling systems, mixing coolant with engine oil, causing additional performance related problems and overheating.

Outside of the cylinder block design, Porsche had issues with the casting process. The cylinder sleeves were cast separate of the engine which is thought to be the reason for the cracking. Given the major issues, Porsche redesigned the engine in 1999 and increased its displacement to 2.7L.

2.7L M96 Engine

The 2.7L M96 debuted in model year 2000 as a replacement to the 2.5L. In addition to a newly designed engine block, Porsche improved upon the casting process to remediate the cylinder cracking issue. While cracking is less prone on 2000+ models, it hasn’t completely disappeared. It produced approximately 225hp and 190 lb-ft. of torque, a 25hp and 10lb-ft. increase over the 2.5 version.

Under the engine codes M96.22/23/25 the 2.7 lasted until 2006 (Boxster 987) when it was replaced with the 2.7L M97 engine.

3.2L M96 Engine

The 986 Boxster S models received a higher-output 3.2L M96 engine which produced 249-261hp and 225-230lb-ft. of torque. The 3.2 M96 also lasted in the Boxster until 2006 when it was replaced by the M97 engine, where it received a displacement increase to 3.4L.

Porsche 986 Boxster M96 Engine Problems

Rear Main Seal Oil Leak
IMS Bearing Failure
Cracked Cylinders
Cylinder Scoring

Porsche is known to be one of the most reliable car manufacturers out there, but that doesn’t mean they are perfect. While glamour, flashiness, and performance typically come along with owning a Porsche, so, too, does the price tag – not just in purchasing one but, also, in fixing one. In order to save you the hassle and the money, let’s look at some of the common problems that Porsche Boxster 986’s encounter and ways to reduce the likelihood of them occurring.

1. Boxster M96 Rear Main Seal Oil Leak

This is the main problem found amongst 986 Boxsters and typically occurs at the rear main seal on the M96 engine. The rear main seal sits where the crankshaft meets the clutch and gearbox. The seal prevents oil from the crankshaft getting into the transmission and damaging the clutch.

Unfortunately, despite numerous redesigns by Porsche, the seal is prone to deteriorating and causing leaks. While some leaks go unharmed and unnoticed, more serious leaks can destroy the clutch and other internal transmission components.

The seal can leak for a few different reasons. If you don’t drive your M96 frequently, the seal can dry out and form cracks that will cause the leak. Additionally, the air oil separator, which is an emissions system, can fail and cause the leak as well. When the air oil seperator fails, crankcase vacuum increases which sucks in excess air and damages the seal.

Rear Main Seal Oil Leak Symptoms

Burning oil smell
Engine rattling / shaking
Excess oil consumption
Shifting issues and loss of performance
Oil leaking beneath transamission

Rear Main Seal Replacement Options

Replacing the rear main seal is not expensive in itself, but oftentimes will require you to replace the clutch. It can be a hassle, though, as fixing the issue is typically not a DIY project due to the fact that the transmission and exhaust have to be removed to replace the oil seal – making the labor more expensive and intensive than acquiring the part.

The oil seal is a cheap part. It will likely leak at some point and they are meant to be replaced. The best way to prevent any damage coming from it, is to have the part replaced early. If you are having your car worked on by a mechanic for something else that requires the transmission be removed, have them replace the oil seal. Other basic preventative maintenance techniques are simply to frequently change your oil, and wait a couple minutes before turning your car off, especially after running it for a while on those hot summer days.

Using the latest and greatest seal, such as the rear main seal from LNE Engineering, can help prevent further leaks.

2. IMS Bearing Failure – 986 Boxster

IMS stands for intermediate shaft. The IMS bearing is a small piece that supports the IMS on the flywheel end of the engine. This small piece often causes large problems for Boxsters, 911’s, and Cayman’s from 1997-2008; however, due to upgrades the IMS bearing is a lot less likely to fail for models from 2006 to 2008. If this part fails, at the very least, you’re looking at having the engine removed, disassembled, and put back together. More likely, you are looking at a complete rebuild or replacement.

The IMS bearing fails for two particular reasons. First, the material that the bearing is manufactured out of is not strong enough for the amount of force and load that is exerted upon it. Second, the bearing does not receive adequate lubrication.

If you are looking at buying or selling a Porsche from 1997 – 2008 (especially pre-2016) do your homework on the car’s service history. Whether or not the car has an upgraded IMS bearing can be the reason for a large difference in its value!

M96 IMS Bearing Failure Symptoms

Metal shavings in oil
Knocking or rattling noises from the engine
Oil leaks in rear of engine

Unfortunately there aren’t necessarily any preexisting symptoms that can warn you that IMS bearing failure might occur. The most tell-tale sign of failure is metal shavings in the oil. This will generally be the first symptom to appear and then terrible performance and engine knocks all over the place will follow. And then the engine implodes, basically.

Constantly check your oil for metal shavings during oil changes. If you catch the issue early on you can likely salvage some components from your engine vs. needing a complete teardown or new engine.

IMS Bearing Replacement Options

The IMS bearing can fail at any time, regardless of mileage. Since there aren’t any warnings signs of IMS failure, our general recommendation is to upgrade the bearing before the problem occurs.

The solution to this problem is expensive, but not in comparison to rebuilding the engine. You can replace the IMS bearing with an upgraded ceramic bearing, but this will typically run you a few thousand dollars. This is also a very labor intensive project, so it’s best to do this in conjunction with another labor intensive project such as replacing the rear main seal.

IMS upgrade kits differ by engine so be sure to make sure you are ordering the proper kit before you buy. You can check out this guide to help determine what kit you need.

3. Cracked Cylinders – M96 Engine

This typically occurs for the 986 and 987 Porsche Boxsters. The liner around the cylinder cracks, usually, due to overheating from a loss of coolant. If you notice your car overheating, or your coolant running low. Fixing a radiator or a coolant hose is cheaper than replacing a cylinder. Furthermore, a cracked cylinder can lead to irreparable damage to the engine, in which case the only option is to replace or rebuild the engine.

If you see or smell coolant leaking from your exhaust or notice your coolant and oil mixing, this is a sign of a cracked cylinder. Your oil will look like chocolate milk and be gooey. Keeping an eye on your engine temp, coolant levels, and replacing your water pump before it fails are the best ways to keep your cylinder from cracking.

M96 Cracked Cylinder Symptoms

Coolant leaking from exhaust
Oil is a milky white substance
Poor performance
Smoke coming from exhaust
Low cylinder compression

4. Porsche Boxster M96 Cylinder Scoring

Cylinder scoring is one of the most common issues with the M96 Boxster and occurs when a cylinder forms deep grooves on the liner. This is usually caused by a broken or defective piston dragging across the wall of the cylinder.

If one of your exhaust pipes is way more black than the other, this is a sign that one cylinder is burning different fuel/oil mixtures. The main symptom of cylinder scoring will be a knocking noise that occurs from the piston dragging across the cylinder wall.

A lack of lubrication in the cylinder and pistons is the most common cause of cylinder scoring. It’s important to change your oil every 3,000-5,000 miles and be cautious of oil levels in between oil changes. It’s not uncommon for 986’s to consume excessive amounts of oil so check in between services and make sure oil levels are always adequate. Additionally, take it easy on your engine RPMs until it gets up to operating temperatures.

Boxster 986 Cylinder Scoring Symptoms

Black coated exhaust pipe
Knocking noise from engine (sounds like lifter tick)
Oil within the cylinders
Cylinder misfires

Is the Porsche Boxster 986 Reliable?

After reading this, you may be a little scared to spend tens of thousands of dollars on a Porsche Boxster 986. It is important to remember that no car manufacturer is perfect and no car is either. The Porsche Boxster, though, has stood the test of time. There are thousands of Boxsters for sale out there ranging in price, age, and mileage – and oftentimes the older cars with more mileage are more reliable than the older ones with low mileage.

All in all, we give the Porsche Boxster an above average grade for reliability, and well above average with an IMS bearing upgrade and proper maintenance. Spending a little more time and money on preventative maintenance will save you tons of money and stress. After all, it is a Porsche, so spending a little more on maintenance is miniscule compared to what you will spend on repairs and replacements.

Porsche M96 Engine Problems Summary

As with all cars, you can expect to replace parts from regular wear and tear, but we covered the main problems that are typically expensive to fix. At the end of the day, if you do your homework on the Boxster before you purchase one, get the IMS bearing upgrade (if needed), and take good care of your car you should expect the Porsche Boxster to run well and for a long time.

Do you have a different experience? Other problems that have occurred for you? Or tips and tricks to improve the reliability? Leave a comment and let us and other readers know!