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.

 

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.

 

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.

 

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 ?

 

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.

 

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.