Routine IMS Upgrade Becomes Possible Nightmare

Long time lurker, first time poster. '01 996 C2 6sp at approx 78k mi, bought Sept 2022, took a local pro shop in the Madison Wisco area in Feb 2023 to have the IMS done & coils replaced and an overall "post-purchase inspection" performed. Runs like a dream, except for some tired suspension components. I've put maybe 500 miles on it between when I got it and when the first snow fell up here, nothing that would concern me even as an extremely paranoid 1st time Pcar owner. Techs took vehicle out, engine ran fine...no misfires, no rattles, no loss of power, not even a rough idle, no CEL, no codes stored, nothing out of the ordinary. They popped engine out and tried to lock it at TDC to fit a new IMS and, well, couldn't because *both* banks were off by 10* (didn't say adv or ret, intake or exhaust). Hand spun the crank a full rotation and still came up with both off by 10*. Oil sample showed no shavings or sparkly bits, but they haven't drained the whole thing yet so no indication that there are any bits of plastic or any other floaties or sinkers. Apparently the techs huddled around and scratched their heads at this one as there were no indications that timing was that far off. Presented with two options : 1) retime the engine, see if it holds (8-10 hours est) 2) full teardown of the engine to replace timing system (might cost as much as what I paid for the damn thing) 3) potential remanued (might cost *almost* what I paid for the damn thing...) They're giving me a few days to figure out what to do, so I'm going to open it up for discussion I guess. - What's a reasonable number for labor for a timing reset? 8-10 seems like a lot considering the engine's already out. - Same question for replacing the timing system - assuming that there's a stretched chain or spun sprocket or wasted tensioner/guide and the whole thing, what's reasonable? - What on earth could have happened here??! I was hoping for a nice long-term stable(ish) relationship with the expected drama and baggage in tow, but this feels like dating a stripper - she's breaking my heart before I really even got a chance to know her.

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If you were off by 10 degrees camshaft deviation.I believe the ecu would have thrown some error codes (check engine light). With that many miles, I doubt the chains are stretched. Did they pull the engine because it�s an AT? Also, before replacing ismb you are supposed to check the camshaft deviation before starting any work. I would change coils, plugs, coolant tank and any other stuff while the engine is out, then run diagnostics to see what the camshaft deviation is and find a shop that knows what they are doing to change the IMSB.

10 degrees is an a** ton and no CEL? It's running the stock tune? Could it have been mistimed during its last engine out?

Thx - yeah, no CEL, no stored codes. Stock tune. Shop is Kelly Moss. I do have an invoice that way back in 2013 the "IMS seal was replaced" at a Porsche dealer, but I wasn't aware that was really a thing. Unless that involved tearing apart the engine and they screwed up the original timing when they put it all back together? Dunno. They're stumped, I'm stumped.

KM is pretty reputable, so at least its in good hands.

I would actually say the shop may be overkill but their shop rate may be in line with others. If they haven�t dropped the sump and inspected what�s inside then I don�t know if I would trust them going forward. Also the fact that they didn�t measure cam deviation and are dropping the engine for this simple procedure is also suspect. My guess is it needs variocam pads. This is a common wear item in the 5 chain engines. The sump would have plastic bits sitting in it.

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Without a doubt, your VarioCam wear pads and chain guides are probably the culprit and it could mean chain stretch too. The wear pads on the camshaft VarioCam adjuster are the first to go, especially if these are the original pads from the factory. Not the end of the world, but I would think the engine needs to be dropped and serviced. BUT... a BIG BUT!... before you pay a serious coin, check and see if you're suffering from cylinder bore scoring. If you are, then a rebuild is necessary. If they're fine, then here are the basic items I would do with engine out service... 1. New VarioCam wear pads/chain guides - then time engine 2. OEM AOS 3. OEM RMS 4. LN Engineering IMS Solution 5. OEM SACHS Clutch Kit 6. OEM LuK Dual Mass Flywheel 7. OEM Water pump with composite impellers 8. Coolant expansion tank 9. Flush all coolant and refill 10. Low Temp Thermostat 11. Serpentine Belt 12. Oil filler tube There are probably some things I'm leaving out. Those are the top one I could think of at the moment. All the best!

I'm fairly confident that checking deviation is one of the pre-qualification steps, at least for the IMS Solution. As others have said, too much deviation should throw an error code. However I'm going to assume that they know what they're talking about and you're in a situation where at the very least you need to address the chain and cam pads in order to get the engine into an acceptable range and continue with the install of your new bearing. As b3freak said, I'd have them scope the cylinders before you spend anything else. If you have excessive scoring (doubtful since you didn't say anything about the typical symptoms) it starts to make your decision about a rebuilt/reman easier. But, 78k isn't a terribly high number in my opinion so it will really come down to your budget and how long you plan on keeping the car. Personally, assuming there isn't scoring, I would not have them rebuild or replace it - I'd have the timing addressed, get your IMSB replaced, and MAYBE an AOS or a few other "while you're in there" items and then just get on with enjoying the car. There are countless things that might fail but ultimately if you spend all of your time and money chasing those down due to "what if" scenarios you're going to spend a ton of money and would likely have just been better off buying a newer car.

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Great advice. The only thing I would change is don't waste your time with the brittle and crappy oem aos. Replace it with the UAOS since you may be dropping your engine, why not put in a permanent aos solution so you don't have to drop the engine again. By the way, Kelly Moss is a highly respected porsche indy here in the midwest.

I don't know anything about Kelly Moss but ... if they are well respected than they must have had their B-team working on this car. A 996 with a six speed does not need the engine to come out to replace the IMS, just the gearbox. While the gearbox is out, replacement of the AOS is pretty easy too. Although once they determined that the engine is 10 degrees out of time (without a CEL?) they may choose to remove it to re-time it especially bank 2, that is acceptable. And if that is all what is wrong, then I would say you are far away from a total engine rebuild. Why would they jump to that conclusion? The Variocam adjuster on the 5 chain engine is well known to have issues that shows up in cam timing deviation and fixing that does not require an engine rebuild. Think hard. Ask more pointed questions.

I just went through something very similar with my 99 C2, except my car threw an error code that turned out to be a bad Cam Actuator. I am located in Cleveland and went to a reputable shop that checked the cam deviation, and trouble shot the actuator before pulling the motor. They ended up replacing all the wear pads, the actuator (1500.00 parts) and while they were in there, I had them replace the IMS bearing as well, which had been done in 2012. The total bill for all of that work was very reasonable I thought < 7K. My suggestion is to follow B3freaks advice. But I am also curious how much they quoted you ?

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Cant speak for the A or B team, but no matter how good an indy may be, it pays for the owner to have an understanding of the 996 issues to help facilitate questions and ultimately the direction taken. The OP in combination with his shop will figure it out. Hope the experienced wrenchers pipe in with their thoughts. It will help with questions for the OP to ask.

It sounds like the shop did not perform a pre- qualification procedure. If so, they would have noted the 10* of cam deviation during the ECU interrogation, and this issue would have taken a turn early on. When FSI was still performing IMS Retrofit work with cars that were coming from out of town, the 5 chain cars had the ECU interrogation done locally before the car even shipped. 90% of those cars failed the ECU interrogation and the car was never even shipped for the work, because they were out of range on allowable cam timing deviations. If an IMS Retrofit procedure is carried out with out of range camshaft timing, the chances of the engine "jumping time" is very probable. This is drama that needs to be avoided for all- involved and can be, if the shop carries out the proper IMS Retrofit pre- qualification procedure, which has been in place and documented since 2007. This is why Certified Installers are always the best choice, because they are bound to this procedure with every job. The key is not to assume that "everything is OK" and that the shop assumes the engines does have a problem, and they have to find it, before it finds them, and you. Since that didn't happen, the shop needs to learn from this assumption, and work with you to address this. Most every 5 chain engine out there needs the 4th and 5th simplex chains replaced, along with their wear pads. At this point I'd say the work to replace these chains, and the wear pads must be done as part of the IMS Retrofit procedure, to restore proper function. The sump plate needs to be removed, so the debris from the wear pads that may have broken off in chunks can be removed, if it is there. The sump should have already been removed as part of the pre- qualification procedure, but I doubt that it was. The pre- qualification procedure was developed for one reason very specifically- to avoid the chances of the exact scenario the OP is experiencing.

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It's interesting that this shop is listed as one of your certified installers. Although we don't know if they were planning to install one of your products.

May as well tear it down. Gotta split the case to replace the IMS anyway.

If it has the original engine,the engine does not have to be ‘split’ to replace the ims bearing.

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If this is the original factory 5-chain engine, it will have a serviceable IMS bearing - either the DUAL ROW or 6204 SINGLE ROW.

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Hmm....

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That is far from just interesting, that is grounds for probable loss of Certification.

Whoops I removed this post as it was not complete ...

Oooohhhh… that sounds bad. Poor Kelly Moss… however will they survive. Oh… wait. KM is one of the biggest and most accomplished independent porsche shop / race teams in the country. They’ll be Ok… I think.

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Like I said, the B-team was on the job.

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Maybe I'm confused, but this is what I read: "They popped engine out and tried to lock it at TDC to fit a new IMS"

I would assume as everyone else has too that the op meant imsb.

The race shops I know are used to clients with VERY DEEP POCKETS and clients who usually never say no when it comes to their race car. You have a street car. Not sure I would have taken it to a race shop for this work. Building a race car, sure Kelly Moss would be one of the companies getting my money along with Fall Line Motorsports up in your area. But again, better have deep pockets when dealing with most of these shops. I would proceed moving forward with caution and make sure they understand your financial situation, whatever that maybe.

It would take a lot more evidence than just 10* off on cam timing at 78k miles to declare a new engine was needed or that the timing chain system needed replacement/full tear down.. But that would be the ideal place to use the "timing chain wear assessment tool" I had proposed/surmised in a recent thread....... that will never get made due to the infrequency of it's need or use or ROI...

Since the engine is already out I would tell them to install the new two short timing chains and cam pads and finish the IMSB install and install a new clutch/flywheel and don't try to "up-sell" me on anything else... At 78K miles I think your long dual row timing chains are ok as is the rest of the engine unless there is evidence to the contrary...

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@168glhs1986 This is sage advice that I often overlook. In OP's defense; if this shop is listed as an LN certified installer, then that certification comes with an amount of presumed knowledge on the shop"s end. That program is designed for laypeople to be able to quickly choose shops they can "trust" due to their requirements to qualify for these programs. Regardless of the shop's primary clientele, if they carry this certificate then I would say any customer should trust they can do the job correctly.

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Any certification worth their weight in salt should have to be re certified on a regular basis. I’m not saying the case here is “marketing” but sometimes they just are that. I once sold a graber drapery rod 20 years ago and now I’m on their list of approved vendors. Sold one rod. I know nothing about their product and don’t endorse it at all. Me personally I take a car to a race shop for their bread and butter services; brakes Alignments fluid service center lock service suspension work Some race shops service engjnes like this… oh it isn’t perfect? Call porsche or bmw and air freight a new crate engine in. Their clients have more money than time. I would think you would want the opposite when servicing a 996 engine. More time than money. With that said when I’m trusting my life in a race car, I’m taking my car to Kelly Moss or TPC racing or Bimmerworld etc. I know Im generalizing and not calling out anyone shop in particular but there are horses for courses as they say. last thing I’ll say about big time race shops like KM. Most of them race there current car / engine. When you get into cars that haven’t been raced in 20 years the skill set can diminish on that particular model. Vintage racing shops not withstanding.

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^^^This.

This nightmare is easily navigated. LN knows about the situation, it's probably been elevated at KM by now to the decision makers. If it were my car, i would call KM this morning and ask them to call LN asap to provide the best course of action. Wouldn't be surprised if they weren't in contact now about what procedures and next steps to take.

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This is assuming they were installing an LN product.

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That is true. All bets are off if it's one of the others.

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Since we do not know all of the dynamics behind this, more information is necessary. Mr. Raby is the person in charge of the CFI program, and makes all the decisions about things involving training, and application of the Code of Conduct. We need more information before it is brought up to him. To the OP, since these LN accounts have the private messaging disabled, please email [email removed] a status update when you know more, so we can bring this up to Jake with the proper information in place. He may choose to use this as a feature on Renncast, explaining why the pre- qualification procedure is in place, and what can happen if it isn't carried out. If nothing else, he can offer some assistance to you on behalf of LN to help get you out of this scenario. Of course, all of this is assuming that they were going to install an LN product. We are here to help if necessary.

Thanks everyone, I appreciate the feedback and the advice. Not a noob to cars, just a noob to Porsche and older Porsches at that. I've been in touch with the shop and we're going to do some more exploratory work to find out why the cam timing is so off. It's a clear red flag that the timing is so off with no other indications that this engine is slightly off it's rocker so to say. Pouring back through the documentation I do have, it looks like there was a "IMS Seal Replacement" performed back in 2013 at 66k miles along with a clutch and flywheel, so its possible that the dealer that performed the work had mistimed it by a tooth or two? I'm not too sure that the ECU would or could be tricked (hacked?) into calibrating/relearning such a deviation as normal though, again especially in the absence of any data or tactile evidence suggesting that anything was wrong with the engine. In my head a permanent 10* deviation would surely give itself away somehow. And look - I regret airing any potential dirty laundry regarding specific processes they follow. If I'm looking at an engine that purrs, throws no codes, no sounds, no smells, and has nothing else in the engine scan to indicate anything but tender loving care, I'm just going to dive in and start working too. KMR comes highly recommended to me by 996/997 guys around the area who I trust, so the trust I have in them is implied. I raised the thread more as a "wtf is going on" given the combination of factors we're looking at here than anything accusatory or disparaging towards anyone. The guys at KMR and you guys here have forgotten more about 996's than I ever have and ever will know. I'm just trying to sense-check and get some ideas for how to tackle this.

I know absolutely nothing about engines either. I rely on this forum and my local mechanics. What a great forum it is.