IMS Fix

[mikefocke]

Jake has a tool for measuring the trueness of the crank and IMS ports in the block that he will protect lest folks steal the design. He has been burned so he takes precautions. I forget if he is patenting it.

[maytag]

Originally Posted by particlewave

Or stop worrying so much and never replace it, other than maybe at clutch change, and never have an issue like 92% of all single row bearing cars and 99%+ of all double row bearing cars.

Already done.

this seems like the right place to try to stir-up the hornet's nest.

As some of you may've noticed, I'm elbow-deep in a clutch job. I decided to do the IMS while I was in here, but now I'm 2nd-guessing myself. Help me think this through, will ya? haha

My car is an '03 S, with 148k miles on it. OF which I've only done about 2000 since acquiring it in March this year. I have no history on the car prior to my ownership. So without having so much as a hint of anything wrong with the IMS, I'm hesitant to throw another $800 into this project-creep that I have going on here.

I've found on Pelican's site, an IMS "update kit" for either single or dual row, priced at $189.. https://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=PEL-IMS-1&SuperCat=Y&SVSVSI=1052&catalog_description=Pelican%20Parts%20M%39%36%20In termediate%20Shaft%20Bearing%20%28IMS%29%20Update% 20Kit%2C%20for%20either%20Single%20or%20Dual%20Row %20IMS%20Bearing%2E

Does anyone have any experience with this? IS this a "good enough" option for u purposes?

[JFP in PA]

Originally Posted by maytag

this seems like the right place to try to stir-up the hornet's nest.

As some of you may've noticed, I'm elbow-deep in a clutch job. I decided to do the IMS while I was in here, but now I'm 2nd-guessing myself. Help me think this through, will ya? haha

My car is an '03 S, with 148k miles on it. OF which I've only done about 2000 since acquiring it in March this year. I have no history on the car prior to my ownership. So without having so much as a hint of anything wrong with the IMS, I'm hesitant to throw another $800 into this project-creep that I have going on here.

I've found on Pelican's site, an IMS "update kit" for either single or dual row, priced at $189.. https://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=PEL-IMS-1&SuperCat=Y&SVSVSI=1052&catalog_description=Pelican%20Parts%20M%39%36%20In termediate%20Shaft%20Bearing%20%28IMS%29%20Update% 20Kit%2C%20for%20either%20Single%20or%20Dual%20Row %20IMS%20Bearing%2E

Does anyone have any experience with this? IS this a "good enough" option for u purposes?

The Pelican kit is simply a new OEM style bearing, so if you were worried about your factory bearing, you can also worry about this one as it is no different.

Considering the effort it takes to do the retrofit, why not use something better than you took out...…………...

[maytag]

Originally Posted by JFP in PA

Considering the effort it takes to do the retrofit, why not use something better than you took out...…………...

See, this is the type of thinking that appeals to me. I always try to think of repairs or replacement of wear items as an opportunity to upgrade.
HOWEVER....
I got 148k miles on the factory unit.... so I'm somewhat loathe to "fix what ain't broke".... y'know?

I'm just not convinced yet that the $600 additional cost (the delta between the Pelican kit and the LN unit) is money well-spent.

Is there any merit to the thinking that the new unit is good for at least 20k miles? that's probably 4 years for me in this car. If I said I'm gonna replace it every 4 years.... I can get 16 years out of it before it equals the same cost as the LN unit.

::sigh:: I'm just trying hard to keep the scope-creep from spiraling out of control here. This car is fun because this car is CHEAP. if it ceases to be cheap, then it ceases to be fun.

here's the funny thing about my thinking: if you told me that I'd get 10hp out of the LN unit, or that it SOUNDS AWESOME.... I'd plunk down that additional $600 in a heaartbeat, hahahaha!

[JFP in PA]

Originally Posted by maytag

See, this is the type of thinking that appeals to me. I always try to think of repairs or replacement of wear items as an opportunity to upgrade.
HOWEVER....
I got 148k miles on the factory unit.... so I'm somewhat loathe to "fix what ain't broke".... y'know?

I'm just not convinced yet that the $600 additional cost (the delta between the Pelican kit and the LN unit) is money well-spent.

Is there any merit to the thinking that the new unit is good for at least 20k miles? that's probably 4 years for me in this car. If I said I'm gonna replace it every 4 years.... I can get 16 years out of it before it equals the same cost as the LN unit.

::sigh:: I'm just trying hard to keep the scope-creep from spiraling out of control here. This car is fun because this car is CHEAP. if it ceases to be cheap, then it ceases to be fun.

here's the funny thing about my thinking: if you told me that I'd get 10hp out of the LN unit, or that it SOUNDS AWESOME.... I'd plunk down that additional $600 in a heaartbeat, hahahaha!

Here's the conundrum of using an OEM retrofit: The factory bearing has somewhere around a 10% failure rate; that could happen in the first 5K miles, or the last 5K miles of the next 100K miles. The OEM bearings failure time line is a scatter diagram, meaning some fail after only a short while, others much further down the road. What you do is totally dependent upon your personal risk tolerance, and willingness to do this all over again it 20K miles, or risk catastrophic engine damage, or spend the next couple years jumping at every odd sound the car makes. Unfortunately, peace of mind comes at a price.

[mikefocke]

My thinking is why use a bearing with the same materials as a original which is known to have a high failure rate.

At the same time, you can go broke trying to upgrade to replace every part that is known to fail.

The classic conundrum surrounding the maintain versus prevent question.

[maytag]

Originally Posted by mikefocke

My thinking is why use a bearing with the same materials as a original which is known to have a high failure rate.

At the same time, you can go broke trying to upgrade to replace every part that is known to fail.

The classic conundrum surrounding the maintain versus prevent question.

this. SO MUCH this.
great summary of precisely the issue behind my indecision.

[78F350]

Let me preface this by saying that much of what I trust about IMS related issues comes from posts by JFP and Mike Focke. If you have a lot of concern about the IMS bearing, get the "Solution" and be done. If you are replacing a bearing that has already exceeded 100k miles as maintenance and aren't constantly listening for the impending failure, the Pelican kit is probably a 'good enough' replacement. The bearing is same as stock, but it does have an improved center bolt.

My guess it that if it has made it this far on the original, the shaft is balanced and true enough to run another factory bearing until your next clutch change.

Me? ...I have a 99 on the original, one with an LN Ceramic, an '01 with the Pelican, and I think I'll put the solution in my '04 next year. How's that for decisiveness.

[The Radium King]

Originally Posted by maytag

See, this is the type of thinking that appeals to me. I always try to think of repairs or replacement of wear items as an opportunity to upgrade.

then consider engine failure due to ims as opportunity to upgrade to a bigger engine. my thinking, anyway. i can't justify going to 3.4 or 3.6 when i've got a perfectly good 3.2 in my car, but if it were to fail then i have a reason ...

[maytag]

Originally Posted by The Radium King

then consider engine failure due to ims as opportunity to upgrade to a bigger engine. my thinking, anyway. i can't justify going to 3.4 or 3.6 when i've got a perfectly good 3.2 in my car, but if it were to fail then i have a reason ...

Now you're speaking to me, haha.


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[maytag]

While I'm waiting on parts, I've been studying-up on the procedure.
I found this video tutorial, which seems to be very comprehensive. http://imsretrofit.com/ims-retrofit-procedure-overview/
However it leaves me with a couple of questions I hope y'all can help me with:

1. At about 1:52 in the video, they say "if locking camshafts on left and right cylinder head is desired, a specially modified camshaft locking tool is required". Does that mean it's OPTIONAL to lock left & right side? What am I missing here?
2. Is it absolutely necessary to remove the A/C compressor to do this job, as described at 2:22? I haven't heard anybody else say they've done this? Will I have to vent the system then?
3. Somebody explain to the dummy here (me) why it's necessary at all, to remove all of the tensioners and lock the cams? Is there really that much tension on the chains that they'd pull the shaft out of alignment with the bearing / bore when you remove that bearing? Is that what's going-on here? I mean, why I can't just pop the one out and the next one back in, the way all the rednecks on the other youtube videos do it?

Hit me, will ya? but don't be too harsh. :-)

thanks in advance.

[JFP in PA]

Originally Posted by maytag

While I'm waiting on parts, I've been studying-up on the procedure.
I found this video tutorial, which seems to be very comprehensive. IMS Retrofit & Procedure Overview – IMS Retrofit
However it leaves me with a couple of questions I hope y'all can help me with:

1. At about 1:52 in the video, they say "if locking camshafts on left and right cylinder head is desired, a specially modified camshaft locking tool is required". Does that mean it's OPTIONAL to lock left & right side? What am I missing here?
2. Is it absolutely necessary to remove the A/C compressor to do this job, as described at 2:22? I haven't heard anybody else say they've done this? Will I have to vent the system then?
3. Somebody explain to the dummy here (me) why it's necessary at all, to remove all of the tensioners and lock the cams? Is there really that much tension on the chains that they'd pull the shaft out of alignment with the bearing / bore when you remove that bearing? Is that what's going-on here? I mean, why I can't just pop the one out and the next one back in, the way all the rednecks on the other youtube videos do it?

Hit me, will ya? but don't be too harsh. :-)

thanks in advance.

OK, let’s start with the obvious: They are working with a 996 engine out of the car; so left and right are reversed. Because of the type of cam locking tool they are using, this is a three chain motor, which is more susceptible to jumping time than a five chain motor, so more care is advisable, and they are locking the cams on both sides. Realistically, if you are doing a five chain in a Boxster, you only need to lock the passenger’s side cam. Because the “off side” head on the M96 will line up the cams differently than the passenger’s side on a Boxster, you would need to modify the cam holding tool for that side on a three chain retrofit .

Because the 996 is a three chain, they are going full “belt and suspenders” to eliminate any chance of jumping time, including removing the chain tensioner under the AC compressor. If this was a five chain, this precautionary step is not required.

[dlud]

Originally Posted by maytag

While I'm waiting on parts, I've been studying-up on the procedure.
I found this video tutorial, which seems to be very comprehensive. IMS Retrofit & Procedure Overview – IMS Retrofit
However it leaves me with a couple of questions I hope y'all can help me with:

1. At about 1:52 in the video, they say "if locking camshafts on left and right cylinder head is desired, a specially modified camshaft locking tool is required". Does that mean it's OPTIONAL to lock left & right side? What am I missing here?
2. Is it absolutely necessary to remove the A/C compressor to do this job, as described at 2:22? I haven't heard anybody else say they've done this? Will I have to vent the system then?
3. Somebody explain to the dummy here (me) why it's necessary at all, to remove all of the tensioners and lock the cams? Is there really that much tension on the chains that they'd pull the shaft out of alignment with the bearing / bore when you remove that bearing? Is that what's going-on here? I mean, why I can't just pop the one out and the next one back in, the way all the rednecks on the other youtube videos do it?

Hit me, will ya? but don't be too harsh. :-)

thanks in advance.

1. You only need to lock the right side on the 5 chain motor. Not sure if it is different on the three chain motor. The first IMS replacement that I did I locked both. The second time I followed the LN instructions (available online) and just locked the right side (bank 1).
2. I've done two IMS replacements in the last six months and have not removed the a/c compressor. The only reason I can think of to remove that would be to access the bank 2 chain tensioner. You can do it without removing the a/c compressor.
3. I have not tried to remove/replace the IMS bearing without removing the chain tensioners. I am guessing that if you don't you may find the IMS shaft being pulled to one side or the other and then not lining up with the engine case.

[maytag]

Thanks, JFP and DLUD. If I'm not mistaken, my '03 S (3.2L) is a 5 chain, correct?

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[JFP in PA]

Originally Posted by maytag

Thanks, JFP and DLUD. If I'm not mistaken, my '03 S (3.2L) is a 5 chain, correct?

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No.
5-chain: Boxster thru 2002; 996 Carrera thru 2001, 3-chain: Boxster 2003 and later; 996 Carrera 2002 and later

[paulofto]

Not that I want to second guess JFP but I thought the 5 chain Boxster went to 2002, 911 to 2001 and then the 3 chain Boxster from 2003 and the 911 from 2002. I'm pretty sure my 03 S is a 3 chain.

[JFP in PA]

Originally Posted by paulofto

Not that I want to second guess JFP but I thought the 5 chain Boxster went to 2002, 911 to 2001 and then the 3 chain Boxster from 2003 and the 911 from 2002. I'm pretty sure my 03 S is a 3 chain.

You are correct; too much time out in the sun for an old man and I suffered a brain fart...….

5-chain: Boxster thru 2002; 996 Carrera thru 2001, 3-chain: Boxster 2003 and later; 996 Carrera 2002 and later

__________________

[maytag]

Ok.... so.... I'm back to (as you said aptly below) "full belt and suspenders"?

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[JFP in PA]

Originally Posted by maytag

Ok.... so.... I'm back to (as you said aptly below) "full belt and suspenders"?

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That depends totally upon your risk adverseness, a lot of people, myself included, have done three chain engines with only one bank locked and the tensioner under the AC compressor in place. That call is yours...…..

[maytag]

Originally Posted by JFP in PA

That depends totally upon your risk adverseness, a lot of people, myself included, have done three chain engines with only one bank locked and the tensioner under the AC compressor in place. That call is yours...…..

thanks! ........