ChristianR3

I haven’t been able to find any consensus about the dangers of these issues for the 987.1’s (I’ve really only looked into Caymans so I don’t know if it’s any different with the boxsters) Obviously I know they’re costly and serious when they do come up but what nobody seems to agree on is how likely or common they are. Some say the bore scoring is bound to happen eventually for every one, and I’ve seen some say past a certain mileage you’re probably in the clear.
So how likely is it really, and if mileage is a factor, what ranges are generally safer and which are risky.
I know everyone says to just get them inspected before you buy but that obviously doesn’t help me when I’m just trying to vet listings

Bxstr

Base 987.1 Cayman/Boxster don't have bore scoring issues. For the others, depends on too many factors. IMS bearing failure rate is pretty low on the 987.1. My recommendation is to find a car that seems to have been taken care of with good service records. Once you do, get a PPI and if not a base, bore scope from the sump, not the spark plug. That will let you know about bore scoring.

Ideally, you'd find a car that had an owner that didn't take it on short trips and used proper fuel which will help with bore scoring. Also someone that actually rev'd the motor out will help with IMS bearing failure as well as someone that used the car regularly. Changing your oil is critical for both.

Some good reading:
https://lnengineering.com/products/t...it=5&mode=list
https://flat6innovations.com/cylinder-bore-scoring/

https://imsretrofit.com/preventing-f...tly%20extended.
https://www.pca.org/news/bore-scoring-how-to-prevent-it

harveyf

Also check out the PCA youtube channel, which has a hour long Tech Tactics discussion of bore scoring.

Charles Navarro

Welcome to Rennlist.

As already mentioned, if you are considering a base model Cayman, bore scoring is not an issue. On Cayman S models or any 99-08 Boxster, Cayman, or 911 with the 3.4, 3.6, or 3.8 engine, bore scoring is indeed an issue and there is no mileage where bore scoring stops being an issue.

It's important to, as part of a PPI, to have the cylinders scoped through the sump. Bore scoring starts at the bottom of the bore and works its way up. If you know the engine is free of scoring, there are steps you can take to prevent bore scoring.

The 06-08 non-serviceable IMS bearing does indeed have a lower failure rate, but preventative maintenance including grease seal removal is necessary to extend bearing life:

https://lnengineering.com/products/t...s-bearing.html

Mansu944

If you are really worried might I recommend the 2006 S. You won’t have to worry about bore scoring or IMS.

Aussie skypig

It’s like many “risk” evaluations.
There are two factors:
1. Likelihood.
2. Outcome.
How “risky” is it to ride a bike without a helmet?
Many of us did it for years and years without injury, so the likelihood is low. But the outcome can be catastrophic. Some people are only alive/functioning today because they were wearing a helmet.

There are debates about the likelihood of IMS failures. But there is no meaningful debate that it can occur on all M96/97 engines. Less frequently on later models, but conversely, much more difficult to take preemptive action (the engine needs to be disassembled. So removing the seal is often the compromise.) Most experts agree that usage plays very little part in the likelihood. Cars that are thrashed, and cars that are driven by grandma have both suffered IMS failures at relatively low mileage. And many, not.

The outcome is a repair bill that can be more than 50% of the value of the car, depending on many factors. One of the major ones is where you live.

Bore scoring.
More dependant on usage factors. So can be dramatically reduced/delayed.
Due to the design and construction, it seems that bore scoring will eventually afflict every 3.4- 3.8 Porsche engine. (Running standard Lokasil bores with the required coated pistons. Not the Turbo/GT3 or aftermarket running Nickasil barrels).
If it happens at high enough mileage, it’s just “wearing out”. If something else wears out first, it’s irrelevant, almost.

It’s not great news. But it seems to be the way it is.

cavediver32043

06CS is a 3.4l F6 with a lockasil block.... it Will eventually score as will a 07 and 08. 09 on have Alusil blocks which Will score eventually. How fast will scoring happen? Well that is determined by Driving environment, temp, starting sequence, driving habbits, oil change intervals/oil grade /type. There is a lot of proven factual research/findings that point to this...Now as far as IMS....06-08 have the big single row bearing with a failure rate of less than a percent. IMS and BScore are 2 very separate issues.

cavediver32043

Not correct....

ZuffenZeus

Actually, if he's talking about the 2006 Boxster S with the M96.26 engine, then bore scoring is NOT an issue. The engine will also have the 6305 IMS bearing like the other M97 engines of that MY.

When Porsche changed to the M97 in 2007 Boxster S, bore scoring issue began to be a problem.

M. Essaie

some comfort

andy7777

Until someone quantifies the problem, it's not an issue. By saying it will eventually occur in every engine from 2007 to 2016 (last I saw LN Engineering was now claiming the 987.2and 981 3.4 cars were also at risk) you're saying nothing. Every engine eventually wears out. What I want to know is in 2024, given a now 17 year history with the engines, how many cars out of 100 with, say, 75,000 miles have a bore score problem? Unfortunately, the vendor who is doing the videos on this issue won't quantify the problem.

Until I can see some real data and not forum anecdotes, Im not losing much sleep over it.

8Lug

Charles, do you think most shops are capable of actually carrying out this procedure correctly? It seems extremely difficult to get the scope into the far cylinders through the limited opening space on each side of the sump, not to mention then having to rotate the scope to view the entire circumference of the bore.

Charles Navarro

Shops that are competent and understand this issue should be capable of carrying out the bore scope inspection correctly.

nate5150

I bought a 2007 Base purely because I did not even want bore score to enter my mind. The peace of mind wins out over a slightly larger engine and bit more HP.

andy7777

Yeah but you'll still obsess over the small chance your IMS will fail.