01' 996 - Sump Debris + -5.8 deviation = no work

Local shop wanted to see the car back in 5k miles, but I brought it back after 800 miles to have them do some winter work on it. Long story short, the bank 1 deviation number of -5.8 has them hesitant to do any work. They recommended cam tensioners, and $5k of work, but when I pushed back on how they got to that conclusion they've now said they aren't comfortable, because they aren't sure it would fix the deviation on bank 1. I actually was game to do that work, as the main guides were all changed 22k miles ago, and seems logical that perhaps the deviation on bank 1is due to VarioCam pads, but again, no CEL so not much to go by. I asked them to at least drop the sump, and see what was in present relative to the last change. It looks like the standard guide debris, and there was also some sparkles in the filter. They are sending oil sample away today, and we'll see what it says. They are being honest, and don't want to take my money, which I appreciate but I'm trying to read between the lines a bit. There's no CEL, symptoms that anything is bad, but it's blocking me from wanting to doing some preventive maintenance this winter, mainly IMS at this point. Any thoughts? I'll see what the oil report looks like, and go from there, but my head can't get beyond the deviation in bank 1. Over the last 800 miles it has gone up almost 1 degree, I actually don't really belive their reading of -5.8, because I drove it for hours prior to taking it in, and got a reading of -5.11 on the Foxwell. I really think it's the variocam pads, but suppose I'll wait until CEL lights up to make it official? Car details: No CEL or other symptoms '01 C4 - 72k miles Guides all replaced at 50k 62k miles previous owner noted bank 1 deviation above 5 Shop found scavange pump on bank one wasn't spinning freely, replaced, and sorted everything out Bank 1 deviation bank down to 4.11 Appreciate any and all feedback. I realize there are a lot of variables, and mainly just wanted to share my experience, and see what others might think. Photo 1: Penny photo is most recent sump drop, only some guide pieces, and some glitter in filter Photo 2: Original sump drop. Previous owner had scavange pump failure, guides replaced, so assuming all that debris was from work done. Recent sump findings 800 miles ago

It’s hard to believe that the chain guide were replaced and the VarioCam pads were not replaced. And there are two big black pieces in the sump. Not sure what those are from? if you have a Durametric you can run a log of actual conditions and watch the deviations. Over the rev range. Is the deviation at all rpm’s or just when the actuators are in effect? What are the cam to crank readings. There are a lot of variables and the Durametric is helpful in figuring it out. I am worried about the big black debris pieces,those are not chain guide or cam pad debris.

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VarioCam pads aren�t shown at all on the itemized build sheet they provided, and I agree. Especially, considering that they never could get deviation under -4 on bank 1, seems like the cam pads would be fair game. There was no big black debris this round, thankfully, so I�m feeling like it has been cleaned out pretty well at this point. There was metal debris from scavenge pump issue, and that was called out in paper work from previous owner. I don�t think they dropped the sump after replacing scavenge. I have Foxwell, and agree that getting some measurements would help. Problem is I don�t have that deep knowledge, and was expecting the shop would help out. I�m getting the impression they simply don�t like 996, several references to getting a 997 to avoid these issues. I�ve got $10k budgeted and they won�t take my money, because of the liability and unknown on what is causing deviation. Frustrating, probably just gonna head to a different shop, unfortunately.

Can you clarify about what else the shop wanted to do or why they thought the variocam pads wouldn�t fix the issue? I feel like there is more info here, the shop knows something about your motor and its history. But also 5.8 is within factory spec and you�ve got a long way until you get any CELs, it�s possible they just don�t want to do unnecessary work (preventative or not) and have an upset customer when the cam dev numbers don�t improve, or only improve by a degree or two. It is weird they didn�t do the variocam pads, but again, you�re within spec. just fyi on my car the cam dev numbers are wildly capricious, others have reported the same thing. DME seems to use averages and the numbers need to be interpreted with a grain of salt - esp if no CEL or symptoms.

Hello fellow Redditor! I�d say check on LN Engineerings website to find a local certified shop to install their IMS solution. They have a fairly intensive process that will qualify your car for the IMS fix which includes figuring out your deviations. Just had mine done and it came with a warranty (two year transferable, lifetime non transferable) so it�s in their interest to make it right. https://imssolution.com/certified-installers/

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Good question. The previous work done to the car was done at another shop, and I shared the paper work with this new shop that showed all work done. It clearly showed that previous shop was not able to get bank 1 deviation numbers down after installing new guides, so I think that�s playing into why they are hesitant, maybe�. Paper trail shows that previous owner took car back into shop 12k after guides were done, because deviation had crept back up to +-5. As far as I can tell from the paper work, they found that bank 1 scavenge pump wasn�t spinning freely, and had noticeable scoring in the unit. They adjustied timing, and replaced pump, and deviation was still at -4.11�ish(low 4�s). This is where the paper work falls off, and that was right before he sold. I�m not sure if the shop offered to do the VarioCam work and he declined, or what the conversation was around deviation, perhaps that�s just not even anything to worry about at that point. The reason any of this matters is that I am trying to get the IMS swapped for LN, along with a bunch of other work. It had the IMS done via Porsche dealer, at 30k miles, and while doing the clutch I was hoping to swap in the LN option. The shop has an IMS pre-qualification process, and if deviation isn�t within some spec they won�t do the work to avoid bad press if something happens due to some other variable. A week after sitting at the shop I got a call that said �Deviation is at -5.8, and we are recommending cam tensioner replacement�. That includes cam pads, etc�when I pressed a little on how they came to that conclusion, and would we know that we�re on the right trail, the conversation shifted to �we don�t want to take your money, and can�t guarantee that deviation will be in better place�. With a clean scan, no misfiring, etc�there�s really no reason to think anything is wrong, other than deviation has move almost a degree within 800 miles, and there is new debris in sump. I feel like they are being honest, they could easily take my money and continue on with the water pump, AOS, clutch, etc�but they are literally saying �just drive the car�. It�s odd, because it is their slow time, they are the �go to� Indy around me. I asked for honest feedback, are they seeing something that is troublesome and not telling me, and they said �No, we just don�t feel comfortable doing the work, based on previous work and symptoms�.

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They are a qualified LN installer, and spoke to LN about what was up with this particular car. It has been a fairly strange exchange with them, and at this point I think I�m going to have them freshen the fluids, install GT3 shifter, and head to another shop.

I just picked up a 150k miles '99 Boxter, the previous owner got misfire codes on bank 2 and the car eventually ended up and was diagnosed with bad chain guides by a dealership. Along with IMS and RMS he was quoted 16k to fix it, so he cut and ran. I didn't know enough before I started this to check the deviation, but there were no codes besides the misfire on 4,5 and 6 when I got it home. This is what I found. I'm thinking a big enough piece of my glitter or a big hunk of guide was sucked into bank one sump and cracked the sprocket. As you can see I had guides of varying wear from totally gone to probably has a few miles left but still pretty bad. Both outers were the real culprits. Anyway, this might give you an idea of what your guides may be starting to do, and could conceivably cause. If this sprocket is the only collateral damage I'm gonna be a lucky fellow! CHeers, good luck! Bank 2 outside guide is gone, inside grooved Bank 2 variocam damage Bank 1 variocam inside on left, outside on right Cracked cam sump sprocket on bank 1

Its been my experience that varicam pads should move the deviarion 3-3.5*. The rest is most likely chain stretch. U can componsate (cheat) for the strech by rotating the cam sprocket a few degrees out of time. It doesnt take much. U should also have the chain tensioners checked. Many people skip the Ln bearing and just replace with the plain steel bearing. Other then the Ln branded Solution all the replacements have a life cycle and need to be replaced anyways.

Cam deviation has a pretty straightforward list of causes. It is strange this shop cannot confidently list those items, which include tensioner pads, the tensioner, chain stretch, and possibly a failing IMSB. It sucks you now feel like you have to go to yet another shop, but that�s what I had to do after spending $3k at a shop that was scratching their head on a failed solenoid and sending me running around the country with my DME they said was bad, but wasn�t. Confidence needs to be present when dealing with a Porsche M96 expert. If they are stumped, that means that haven�t run into this situation before. This situation is not uncommon, IMO.

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"pump failure, or pump wasn't spinning freely" not sure exactly what that means..? Did pump seize up...? How and why does one determine "pump not spinning freely" What happened to cause a tech to check the SP..? Might help to know what sorted everything out exactly means..? Seems to me, someone(previous owner) wasn't telling you the whole story, purposely... Seems dependent on rpm when SP failure happens, could break the drive snout, or beak the cam gear, or break the chain. At the very least, lots of pressure on the chain when pump stops, suppose it could also damage/stretch the chain. if chain breaks, valves hit pistons for catastrophic damage. my educated guesstimate,,, Previous owner had a SP failure, probably a more basic less damaging one like the snout just broke off from ingesting debris like a broken piece of chain roller. Or maybe a broke cam gear. Shop made a basic repair, after repair they still found cam timing way off after basic R&R, when it shouldn't have been. Shop then recommended engine out chain replacement($$$$) but warned that could open up a bag of worms($$$$$$) once cases were split to replace chain. Of course they are correct. On a high mile m96 engine, once cases are split and cylinders are seen/measured, one thing leads to another and we all know whats next. So, with that info the previous owner decide to just go with the current repair and live with the 5.8� cam dev, and try to sell it like it is. without stating the recommendations from the other shop. the new shop figured out what was going on and wanted no part of it, can't blame them... jmo

My situation is similar... confusing Indy recommendations for high Cam Deviation. 996 is a 2000 C4 with 107,000 miles. No CEL and No drivability issues, runs great no smoke no rattles. And last (and all) oil change show no issues - no metals on Magnetic drain plug, or bits in the filter. Deviation on bank 1 = 7 and bank 2= 4. Note both Indy's are very well thought of and over my 25 years of ownership of 3 Porsches they are both trustworthy. So first Indy says we need to replace the Complete VarioCam Adjuster assembly - both banks @ $3300 parts cost - plus other bits, gaskets, plug tubs, Tax, etc. - plus 18 hours labor = $9500 repair. Said the VarioCam Assembly has been noted as a problem and comes with guides so swap the whole thing..Add to that fixing a few issues with minor oil leaks and I am looking at $11,000 repair. And they say "don't drive any long trips!" Second Indy - with a 996 master Mechanic that knows this 996, say it is OK to just drive the C4 till the CEL is on. Says the Solenoid's should be replaced and Guides and the cost for parts on both Banks is about $1600 - and Labor about the same so my total cost is about $6000. Saving $3500 is significant. Note: I have TechArt Headers that have to come off so a bit more labor on both estimates. So Any thoughts on replacing the Compleat Vario Cam assembly - vs - parts of it??? As it is an every week - one day driver even in winter - and we do winter tours here I plan to drive it and hope to put off the cost till next year - January ???. Appreciate comments... Love the 996 - owner for 12 years, and it is a keeper - hoping to Grow Old together and manage "Medical" cost.

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I tend to think the 2nd mechanic route would be more likely to resolve the issues. The solenoids, I don�t think, have any variability to them, meaning, they work or they don�t, so I suspect he wants to replace them because he�s already in there, and they can fail. I suspect the pads are the main issue with your engine. There has to be a way to measure chain stretch while those mechanics are in there. Because you have only 3 degrees of separation between the cam banks, but 7 absolute, I�m suspecting the chain that runs between the IMSB and crank, along with the chain tensioner and pad to be potentially part of the problem? The problem is, I don�t think there is an easy way to replace the tensioner pads/rails that run between the IMSB and each bank, or is there? And I don�t think the chain rails between the crank and IMSB are easy to replace either? Someone please correct me here. I had -4 and -2 before my solenoid failed. I then had all 4 tensioner pads replaced and went back to 1. The pads in the original 3.4 5-chain engines are a known wear item.