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Discussion summary
YOUR RESEARCHM96/23 Hydraulic Lifter Failure, with pics
Leading reported evidence
Replace better cam lobe oiling
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
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Performed · outcome unconfirmed
The retainers or housing that holds all the lifters was also changed for better cam lobe oiling.
Leading evidence: 'Replace better cam lobe oiling' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace better cam lobe oiling' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
As you can see in the pictures the top of the lifter has been hollowed out by the cam, and when the cam ran into the internal mechanism that provides oil pressure to set the valve lash the cam lobe was damaged.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
There are too many small differences to go into here but another one of them is that Vario-Cam actuation is different on late model M96 engines and that design change carries over to M97 engines.
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Suggestion
As you can see in the pictures the top of the lifter has been hollowed out by the cam, and when the cam ran into the internal mechanism that provides oil pressure to set the valve lash the cam lobe was damaged.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
There are too many small differences to go into here but another one of them is that Vario-Cam actuation is different on late model M96 engines and that design change carries over to M97 engines.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
As you can see in the pictures the top of the lifter has been hollowed out by the cam, and when the cam ran into the internal mechanism that provides oil pressure to set the valve lash the cam lobe was damaged.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
As you can see in the pictures the top of the lifter has been hollowed out by the cam, and when the cam ran into the internal mechanism that provides oil pressure to set the valve lash the cam lobe was damaged.
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16 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Planet-9: 1 discussions
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Generation: 20261027T035758Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
This is more for late model
986
owners but we have some very good pictures of a 13,000 mile M97/23 engine that from what we can tell has had a lifter failure. The replacement lifters have an updated part number. We don't have them yet so we don't know if there are any visual differences.
As you can see in the pictures the top of the lifter has been hollowed out by the cam, and when the cam ran into the internal mechanism that provides oil pressure to set the valve lash the cam lobe was damaged. We suspect there is an issue with the surface hardening process of the lifters and that may be why they have been superceded.
I will keep updating this as we get more information but this engine is getting a new intake camshaft and all new lifters on this side of the engine. Perhaps PCA-TECH has some insight into this failure.
Also visible in the pictures are some striations in the good lifters. These just deep enough to feel with a fingernail. The reason everything is round is that the lifters rotate when the engine is running, which is why the bad lifter is so smooth and shiny. On older
Porsche
water cooled cars with similar types of lifters this type of surface lifter wear is not usually so pronounced.
I know that several CC members have had lifter issues, I figured people would like to see the parts.
We now have two M96/23 engines apart we have looked at all 48 lifters and noted that some lifters are worn more than others. At this time I don't have a good answer as to why this particular lifter had such a massive failure.
K-Man S - Which lifters were replaced? The intake lifters on the variocam plus cars are very different. The exhaust lifters should be the same.
Also I made a typo when I started the post the engine is an M96/23 not an M97/23, perhaps you can fix this for us.
I don't have the numbers with me right now, I will post them when I have them in front of me.
Hello Drew,
The lifters that are in the car are most likely 996 105 041 50. These are replaced by 996 105 041 72. The original ones had a tendency to wear prematurely or shatter by design. The retainers or housing that holds all the lifters was also changed for better cam lobe oiling.
Best,
Scott
I wonder if they were relying on internal oil to provide strength. If so, something as simple as an air bubble could have lead to the failure. That thing definitely wiped out the cam lobe too.
Cool pics. I enjoy these looks inside the engines. Thanks...!
Sad that this happened to a 13,000 mile engine that is most likely out of warranty. That's why I'm driving the ---- out of mine.
The primary difference is the VarioCam Plus. The M96 had VarioCam. The M97 has VarioCam plus. VarioCam shifts the timing between the intake and exhaust cam and relative to the crankshaft. VarioCam Plus does that and it has two different intake cam lobes that are controlled by the
DME
.
Scott and Drew may be able to share some more subtle differences.
Gator is not entirely correct on the differences. Some are very subtle.
The M96/23 and 24 for instance have most of the updated cylinder head items that are also in many of the M97 engines. Some other differences:
The M96/20 was cable throttle, and then the M96/21-22 had similar architecture but with E-Throttle. There are too many small differences to go into here but another one of them is that Vario-Cam actuation is different on late model M96 engines and that design change carries over to M97 engines.
Scott - Those are the part numbers I have for the lifters. Looks like the old lifter carrier as well, unfortunately we only have a casting number to go by but that will likely get replaced as well.
Ken - The thread title on the main thread listing page still says M97/23 even though I edited the title in my first post.
Ken - Fixed now, Thank you! :cheers:
pepys -
According to the parts listing the 72 lifters are installed in 987 Boxsters with M96/25-26 engines for the exhaust valves.
The 72 lifter is the replacement part for the 50 in the earlier engines.
The M96/25-26 engines have VarioCam Plus so they have different intake lifters Part #996 105 255 22
987
Caymans
M97/20-21 all have the 72 lifter for the intake
A similar situation is true of 996/997 cars.
The replacement lifter for M96/01-02-04 is the 72
The M96/03 (2002 and up 996) uses the 72 for the intake
For the 997 the M97/01 and M97/05 uses the 72 for the intake
We performed the repairs as I descibed earlier and the engine now runs flawlessly, fortunatey there was no damage to the valve tip or the cylinder head would have had to come apart.
Given the wear on the lifters due to what seems to be mostly a lack of lubrication it is highly likely that we will see this type of failure again in the future.
This is a source reference. Confirm exact model applicability in the original material.
