Speaking of front tires: (edited)

Getting ready to replace my clutch. Figured it would be foolish to not replace the IMS bearing at the same time just to "reset the clock." I'm going to inspect the wear on the original bearing (~101k) before I decide whether to install the TuneRS DOF retrofit as well. But I also want to know what the latest failure stats are on it. I know Pedro is associated with that product. So, maybe he can enlighten me? How many installs/miles so far? How many subsequent failures?

Thanks!
Jay
99 Boxster

... failure rate of the TechnoFix DOF is zero.
Units sold to date just over 1,000.
Miles driven I would estimate 1,000,000.
The only way to really inspect wear on a bearing is by cutting it open to inspect the inside of the races.
Happy DOF'ing,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Quote
Pedro (Weston, FL)
... failure rate of the TechnoFix DOF is zero.
Units sold to date just over 1,000.
Miles driven I would estimate 1,000,000.
The only way to really inspect wear on a bearing is by cutting it open to inspect the inside of the races.
Happy DOF'ing,
Pedro

So I guess that's really a 'non' failure rate, Pedro, and quite impressive.

If you're gonna keep your Boxster for a while, now's the time to do the DOF, Jay. And no, I have no financial or other interest in the product, which reminds me.....

There's a MF curmudgeon around here, who may show up soon demanding 'proof positive', he's never asked of his other 'friends'.

"A mile of highway will take you one mile. A mile of runway will take you anywhere."

Actually, that averages only 1,000 miles per installed DOF. Not dissing the product, just stating the facts. Not enough evidence to put a non-failure rate on it. Porsche was able to blow that mileage figure out of the water before its first engine went poof due to the IMS. Now, we are all running for the hills or solutions.

( and note: i'm a big fan of the DOF and think its the best, or at least best price/results, solution out there)...

. . . we wont have meaningful data for about 4 years. Even the original design rarely failed before 4-5 years and/or 15-50k miles passed. they were ticking time bombs, maybe, but they had some fuse.

Any data we saw today would indicate install errors or defective parts - rare but real facts of life.

We have to believe that these bearings fail for a reason. And that reason appears to be poor lubrication compounded by acidic oil.

DOF fixes one and reduces the 2nd.

Most other fixes simply make the bearing tougher and better able to survive this poor situation.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

The DOF doesn't have any moving parts. Consequently, I think its only means of failure would be if the oil line leading to the flange broke, or became plugged, or if a piece of hardware (fitting or flange) broke. Both of these events are probably very unlikely.

It may be that the OP intended to ask, in referring to 'failures', whether there have been any failures of IMS bearings in engines where the DOF has been installed.

The answer to that question may also be 'zero'

And that's why i answered as i did - the IMS would likely not fail for years even without DOF, so failures with it are not expected, unless the IMS bearings were already in grave shape. That should be caught when the DOF is installed, so again we should assume those cases approach zero.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

I understand, Grant.

My reply wasn't so much a reply to yours (though that's where it ended up in the chain), as it was as a comment that the DOF itself isn't likely to fail - the question is whether bearings have failed after the DOF was installed. As you point out, likely any 'iffy' bearing, and probably even good bearings, were replaced at the time of the DOF installation (except in the case of the larger 2005+ bearings).

Even if an IMS bearing were to fail after a DOF installation, the DOF might very well still be the best solution. The bearing could have been on its way before the DOF was installed, or it just might be a contrary bearing, bound and determined to fail, no matter what.

Grant

gee-lenahan-at-gee-mail-dot-com

I was in fact looking for information on post DOF-install bearing failures. While enough time may not have elapsed to say for sure whether the DOF is in fact a permanent fix, we can at least rule out the possibility of it causing short-term failure. For instance, I read somewhere (it may have even been here) that over lubrication can put undue stress on ball bearings. Something about the viscosity of the oil or some such. So, it's at least encouraging that there have been no failures yet. We may not be able to extrapolate a lifetime failure rate of 0% from what we have, but we can say, "so far, there have been no failures." That's worth something.

When were the first DOF installs?

... for post DOF installed bearing failures. I repeat zero.
The million miles is also a very conservative estimate because the first units were sold 14 months ago.
If you figure 6,000 miles per year per vehicle in one year with 1000 units you would have 6,000,000 miles.
Obviously the latest ones haven't driven that many miles, but it's safe to say that it's 3,000,000 - 4,000,000 miles so far.
The first DOFs were installed over thee years ago. Some of those cars have already put over 30,000 miles post DOF.
Two have put over 7,500 track miles (Boxster Spec Racers).
Over-lubrication is not good, as you note. That's why the DOF meters the amount of oil that goes into the bearing making sure it is the adequate amount to cool and lubricate it.
Happy DOFing
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

I was just clarifying for Roger987.

The stats you provide are very good and even if there simply hasn't been enough time elapsed to say for certain that the DOF is the permanent solution, there at least hasn't been any evidence to the contrary.

So you've got that going for you. Which is nice.

"A mile of highway will take you one mile. A mile of runway will take you anywhere."

Jay
If the bearing +/- DOF lasts longer than your clutch ,is that a big problem?
I would be comforted knowing I could check the IMS at every clutch change and replace it as a routine maintenence item(like a clutch plate) .The bearing is not expensive,you already have the tools you only have to remove the DMF to check..

clutches can last a very long time. if they were, say, 30k maint items i would agree with your position. But i certainly hope to prove that interval, very, very wrong!

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

I put 101k miles on my original clutch and the only reason it finally went is because it was ruined by some one who rented my car from me. At 100k+ mile intervals, the odds of the bearing surviving is less of a sure bet.

Jay

I opted not to change it when the original motor was replaced by Porsche under warranty at about 45,000 miles. (That was done because of the repeated RMS failures. Fortunately this last time a mechanic pulled the transmission when everything was still warm and found the crank bore eccentricity by using a micrometer instead of the "go/no-go" tool. When a Porsche rep had him check it again it was already going back into spec as the motor cooled.)

on a 40K mile schedule is the front tires.

With 34,000 on the fronts (Goodyear Eagle F1 Asymmetric 2 N0) I've lately noticed more actual characteristically Porsche road texture coming through the steering wheel. I guess there will be a certain Goldilocks mileage zone wherein they'll feel really good (maybe 10,000 miles?) before their tracking and water evacuation begin to suffer. The rears got changed maybe 7-10 thousand miles ago. Obviously, I'm not being too mindful of wear vs. mileage. When they "need" to be changed, they get changed.

This past cold season the Michelin PA4s were on for around 4 1/2 months / several thousand miles. They got some abuse when I went to Alabama in December and by the time I got to the state it was 82º out. I drove no more than the speed limit and (gasp!) even lower hoping to conserve the tread compound. Good thing I had them on as the temperature dropped precipitously the next day and upon going home hit snow by the time I got to Maryland. The PA4s perform just about as well as the summer tires, at least at 6/10ths driving, but I wish they had more snow traction-- not that I want to drive in snow with this car. I attribute a good part of these negative and positive aspects to the fairly shallow tread depth. Perhaps I'll try the N-spec Continentals winters next time.



Edited 1 time(s). Last edit at 07/21/2014 10:34AM by Laz. (view changes)

Try the BFG g-force comp-2 sport.

Snowflake rated (although i would not test that theory if i could avoid it). Cheap. Wear very well. Stick well and are predictable (except, as always, when cold)

I have them as street-ies on the 986 and street (and occasional) track on the wagon.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

or sugar coated by suggesting this can be done when the clutch is done, as if clutches are short lived and cheap to replace in their own right.

It is my opinion that if one believes his car is in need of an IMSB upgrade that this be done regardless of the condition of the clutch. If the clutch when exposed shows signs of excessive wear and is believed to be too close to its end of life to reuse one can always have the clutch renewed.

Then if the IMSB upgrade requires periodic replacement to do this based on the mileage guidelines offered by the IMSB upgrade maker with the clutch's condition as being secondary. As with the initial installation the clutch should certainly be evaluated and renewed if deemed appropriate.

Of course, the owner could elect to replace the clutch regardless of its condition at every IMSB upgrade/renewal service period but oh the cost...

I REALLY don't intent to beat that dead horse again, but, before we ponder "the failure rate for the IMSB DOF retrofit," do we have any REAL DATA on the failure rate of the 986 (or early 987) IMSB? I'm NOT a denier. I recognize that there have been a significant number of IMSB failures and that the consequences of IMSB failures are serious (maybe "fatal," considering the market value of 986's). But, statistically, what are we talking about? Consumer Reports hasn't given early Boxsters particularly bad marks for engine reliability, and Michael Karesh's TrueDelta website doesn't indicate that IMSB failures are all that common. So is this just internet-enabled mass hysteria or is there a quantifiable justification for spending $1000 (+/-) to prevent catastrophic failure of a $15,000 (+/-) automobile?

Quote
yellowesty
I REALLY don't intent to beat that dead horse again, but, before we ponder "the failure rate for the IMSB DOF retrofit," do we have any REAL DATA on the failure rate of the 986 (or early 987) IMSB? I'm NOT a denier. I recognize that there have been a significant number of IMSB failures and that the consequences of IMSB failures are serious (maybe "fatal," considering the market value of 986's). But, statistically, what are we talking about? Consumer Reports hasn't given early Boxsters particularly bad marks for engine reliability, and Michael Karesh's TrueDelta website doesn't indicate that IMSB failures are all that common. So is this just internet-enabled mass hysteria or is there a quantifiable justification for spending $1000 (+/-) to prevent catastrophic failure of a $15,000 (+/-) automobile?

The answer is really very clear at this point. After the Porsche class action suit over the IMSB, from the data turned over by Porsche, the statistics are that the dual row IMSB (from app MY 97-2000) and the updated, non serviceable IMSB from about 2006 up, have a failure rate of less than 1% . That leaves the single row IMSB, from roughly 2000-2005/6. They have a Failure rate of around 8%

If you have hours to spend, go to Rennlist where there are several threads that will give you all the details on the failure rates of the IMSB based on Porsche class action data.

Thanks.

... did not offer any official numbers on failure rates, except talk about a 10% general number.
All of the sub-numbers are just conjecture and WAGs.
From what I've seen, IMS bearing's failure rates are:
'97-'00 cars about 2.5%
'01-'05 cars about 14%
'06-'08 cars about 1.5%
'09 and newer are 0%

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Quote
Pedro (Weston, FL)
... did not offer any official numbers on failure rates, except talk about a 10% general number.
All of the sub-numbers are just conjecture and WAGs.
From what I've seen, IMS bearing's failure rates are:
'97-'00 cars about 2.5%
'01-'05 cars about 14%
'06-'08 cars about 1.5%
'09 and newer are 0%

The numbers are not wags. I'm sorry, your anecdotal evidence, based on a very small sample of cars you have serviced does not trump evidence which was compelled pursuant to a legal proceeding where Porshe was forced to disclose evidence on hundreds of thousands of cars. It's incontestable that the numbers which Porshe had to disclose are what they are. And what are you saying? The numbers you quote are very close to the numbers that Porshe discloses. Both you and porshe agree that dual rows have a very low failure rate and single rows have have signifant risk of failure which warrants proactive measures.Does a 2.5 % failure rate according to you versus less than one percent according to Porshe mean that you have to replace t he IMSB tomorrow? Would anyone say I have to replace my IMSB tomorrow because the chance of failure is 2% as opposed to less than 1%? I don't understand why you contest Porsches numbers.

... unless they are explained better.
For instance, you say 01-04 is 8%, I say almost twice at 14% but those are averages.
There are some people who fall in this category and say I can live with 92% in my favor.
But they may own an 04S SE 550 which has the highest failure rate of all, over 20%.
So the important thing is to know your own risk which mostly depends on the way you drive, or don't.
I'm working right now on a 2002 Carrera with 7,000 miles. The owner had never heard of the IMS issue.
He's in for a clutch replacement but because he never knew about the issue he doesn't think spending an extra $800 in the DOF makes sense.
To me, that's very risky.
What I can't grasp is how someone can have such a great driving car as an 02 Carrera and not drive it.
The car deteriorates completely in this SoFla climate.
All of the seals dry up and leak the soft top gets moldy, the oil gets acidic, and on and on.
It's not as if the car will appreciate like the old air cooled ones, so what's the point in not driving it?
Happy Driving
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Quote
Pedro (Weston, FL)
I'm working right now on a 2002 Carrera with 7,000 miles. The owner had never heard of the IMS issue.
He's in for a clutch replacement but because he never knew about the issue he doesn't think spending an extra $800 in the DOF makes sense.
Pedro

Wow! Can't imagine what you'd have to do to wear out a clutch in 7,000 miles. The previous owner must have limited his driving to about 600 miles of burnouts each year. In Florida you can't even do any hill holding with the clutch.

... another customer has a beautiful 2004 Speed Yellow S with a manual.
I commented: "What a beautiful Boxster"
He said it was a Porsche, not a Boxster.
I didn't think it was wise to explain any further after he told he that he googled yellow Porsche and that's what he bought.
After I changed the oil and as he left, he must have worn out 50% of the clutch.
He'll be back soon
Happy Boxstering
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

there's pretty good anecdotal evidence that not all cars fail at the same rate. Use and maintenance makes a big difference. Cars that are driven more, fail less frequently, and cars that have the oil changed more fail less frequently. This squares with the failures methods most often put forward by knowledgeable folks like Ed, Pedro etc.

So, if one has a garage queen, and the oil rarely gets hot for long periods of time, and gets diluted and acid, the numbers probably grow greatly.

OTOH daily driven cars tht get hot for extended periods and regularly, not so much.

My oil, for example, has dilution below the measurement threshold, and is not particularly acid. That's due to hard, regular, use.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

This whole thread is as good a summary of the IMS issue as I have seen. What's missing is a discussion of failure possibility in 986 and early 987 engines not due to IMS issues. We too often regard ourselves as typical Porsche owners, but Pedro's comments bring us back to reality. We're probably a very small enthusiast subset of Boxster owners. Based only on my own observations on postings here and some on other websites, there has been a big improvement in reliability with the 9A1 engine. There were also comments in the Tech Q & A section of the latest Panorama on page 128. The author states: "The 9A1 flat six with direct fuel injection used in 2009-and-later Porsche sports cars has proven to be quite reliable." I encourage anyone interested to read the entire response.

on at least one UK Boxster/Porsche forum about how crummy the new engines are. You want to see a British Boxster owner get all pale and weak in the knees just say "bore scoring".

Now understand I do not buy into the opinion the new engines are crummy or even have any real weakness, but it is hard to offer any counter opinion/argument when so many owners seemed rather pleased, in some twisted/perverse way, with the idea that the new engine is no good.

Based on what I have read there appears to be no real science behind the claim the engines are crummy, just the usual few failures that appear to me to be extrapolated into a 100% failure rate in hardly no time at all unless one signs up for some kind insurance/extended service contract, which a good number of UK owners appear to be doing. Then of course, they are completely resistant to hearing any challenge to this new engine is bad refrain as they have money bet on its being bad.

You're right. I don't get out much anymore, just hang around here reasonably confident any real issue will surface here sooner or later. I did a lot of internet searching before purchasing my Boxster since I wanted to know what I might run into keeping the car out of warranty. Interestingly the only major problem (under warranty, thankfully) was a broken shift linkage cable which seems to be a very rare thing.

There appear to be a small number of fundamental design issues that are widely criticized, and, tellingly, have been rectified in the 2009+ DFI motors:

1. IMS lubrication (lack of)
2. Piston geometry offset (lack of...)
3. Oiling/dry sump (lack of...)

All 3 have been addressed - there is no more IMS, the pistons are no longer symmetrical nor identical, and the oiling has been greatly improved, especially for the problem cyl ( i forget the numbering scheme) and under high lateral G loads.

We ignore many of the strengths of the M96 - very hard, wear resistant locasil coatings so that people like you can approach 300k with good compression, and motors routinely go 150k+ with no traditional ring/cyl wear. Ditto the valvetrain, minus some weaknesses in the tensioning and plastic guides (which are what killed my/Bruce's motor, not the IMS after all).

I maintain that many issues are a result of these cars frequently being garage queens.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

Quote
MarcW
on at least one UK Boxster/Porsche forum about how crummy the new engines are. You want to see a British Boxster owner get all pale and weak in the knees just say "bore scoring".

Now understand I do not buy into the opinion the new engines are crummy or even have any real weakness, but it is hard to offer any counter opinion/argument when so many owners seemed rather pleased, in some twisted/perverse way, with the idea that the new engine is no good.

Based on what I have read there appears to be no real science behind the claim the engines are crummy, just the usual few failures that appear to me to be extrapolated into a 100% failure rate in hardly no time at all unless one signs up for some kind insurance/extended service contract, which a good number of UK owners appear to be doing. Then of course, they are completely resistant to hearing any challenge to this new engine is bad refrain as they have money bet on its being bad.

The UK isn't the only location throwing stones at the 9A1 motor--Jake Raby has added a few negative comments about it (bore scoring/ rod bolts/cam chains IIRC during his 981 conversion to a 4.2L--(in Pano?).

I don't pretend to know all the facts about the 9A1 motor, but relative to it's predecessor, there are far few horror stories about the motor going boom for any number of reasons. The P9 site has a lot of Cayman/Boxster 9A1 owners on it--with a lot of guys doing track days--and there are precious few complaints about this motor after having been in production now for 5 years.
Seems to me if it was the stinker that the Brits and Jake think it might be, the cat would be out of the bag by now.

We cant say they are perfect fixes, or that there are not new issues, btu the big 3 had attention paid to them.

Track issues with the new motor, from what i have seen, is pretty much zero.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

As far as I can tell with the computer generated pseudo dipstick, my oil consumption is zero. Ordinarily one doesn't report good news, but I thought I would throw that out.

1. i had never heard about this. Its a UK thing, which suggests that there may be a social hysteria element....
2. bore scoring could come from highly stressed pistons that don't track perfectly - a known compromise Porsche made in the M96
3. bore scoring could come from failed lubrication, e.g.: track use when the sump sucks air

#2 and #3 are fixed in the DI motors.

My car that I've had from new burns zero oil under all circumstances

The car i put a used, garage queen motor in sometimes burns oil, mostly under track use. Also shows ring/cyl wear metals in UOA testing. Small but elevated. So it is possible, but i'd point my finger at lubrication.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com