M96 Rebuilders in Southern California - pleasse advise/recommend

Hello everyone, I am starting a new thread now that my issue is conclusively diagnosed and a rebuild is necessary. I have a beautiful factory aero 2000 996 with 57,000 miles. Unfortunately, the engine suffered four misfires out of nowhere Saturday night, and we heard a knocking sound. The shop eventually found metal in the cylinders and oil filter. There is no sign of scoring, but otherwise the cause is unknown. I will be commissioning a rebuild. I have LN IMS solution by the way. Two questions for the group: 1. Can I please get recommendations for an engine rebuild in the Southern California area? I have so far been pitched Auto Strasse and Vision Motorsports. It has been emphasized to me that I need someone with M96 experience. 2. Can anyone recommend what I should do to make this bulletproof? Auto Strasse is apparently quoting me $13,000-$18,000 for what essentially amounts to a top-end refresh. They will not be sleeving cylinders or doing forged pistons/rods etc. for this price. I am a little surprised, but maybe this is the Southern California Porsche tax. I would appreciate any suggestions and will be happy to provide additional information as necessary. my poor car, waiting for help

Is Torrance near you ? Callas Rennsport are highly rated . Torrance Porsche and BMW Repair - Callas Rennsport https://share.google/MNeF7dqxsKdjx7MHd

Try Vision Motorsports - Irvine, Euro-Tech, 9xx - Long Beach. Callas is top of list if you can get your engine in the queue, but probably not the budget call. You might entertain the idea of shipping the entire car to Slakker for a good sum less than what you’ll get charged in your area for a tear down and rebuild.

Please don't make a decision based off a half quote. You don't know what is wrong yet. If seems you should have 3 or 4 quotes from each place, each at some logical break point so you know the worst case going in: topend, +bottom, +crank, +core. Good luck. It looks like a beautiful car.

I am not surprised that the $18,000 quote is for a top-end-only job but based on the information provided you should plan for a full rebuild from the crankshaft up. I have done this three times in the last 2 years, twice on 996 variants. Your 2000 model has several options including a factory short block for a fairly reasonable amount, all the way to a $6,000 LNE reconditioned block. There are advantages to each solution that needs to be discussed at length between owner and builder. I am afraid you are not going to get out from under this scenario for less than $25,000. That is a nice looking sample and if it is your forever car, it might be worth saving. At this point, this is no longer a financially sensible save. You have to do it for love. I don't live in socal anymore so I cannot recommend a shop. A shop that has done a rebuild on a 996/997 platform is absolutely required. I am sure they are out there, but as in any other trade, good shops have miles long waiting list and waiting time. Then once it gets under the knife there will be more waiting. You either wait for LNE lead time of 12 weeks, or wait for Porsche factory block delivery of 10 weeks, or wait forever for the machine shop to do its thing. Sorry, there is no good news at this point.

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I would sit the car and take as much time as needed to find the right builder. You have lots if options. 1. Factory short block swap, which may be the most cost effective. But you need to find a Porsche specialist or dealer that can accurately do it. 2. If you want a local shop to handle a rebuild or handle a LN/FSI rebuild swap, you can go to LNs website and identify shops that are certified by LN. 3. You can call LN directly and get suggestions. 4. You can call Slakker directly and get suggestions. 5. You can also go to a number of local PCA events, my suggestion would be track events, specifically PCA club racing events, and ask around for the best Porsche shops for handling a M96 rebuild. You will find many Porsche shops there that support the M96/M97 race cars. These guys know how to rebuild an M96. These are the guys you want. 6. You want to talk to guys that are maniacal on spending more time and money on their m96/97 engines. You will find them at the track, not at cars and coffee. If it sounds too good to be true, it is. IMHO, you are better off doing it right than doing it half assed and having to spend even more money all over again. Good luck!

I dont know where you are in relation to this place, but this shop in Southern Pasadena rebuilt my 2000 C4 with 137k miles in 2018. It was a full rebuild into the bottom end where they ridge-reaned and honed the cylinders, piston rings, new main and rod bearings, etc...rebuilt cylinder head, and lots of parts. Old school place where they were still handwriting everything on the work order. All for $15k. For what its worth.....

IMHO, no way a reputable shop can give an accurate estimate without knowing what the core engine needs to be rebuilt correctly. 1) You say in your other thread that shop found metal flakes in oil filter. = very good chance crank needs to be replaced $6000 2)You say in your other thread that shop found metal flakes in cylinders but cylinders looks fine, and failed leak down test showed 20-30%. So if cylinders look good but leak down is bad could be a problem with heads/valve train..? Head cracks, lifters, lifter tray, valves, valve guides, seats, cams, actuators, etc...All expensive parts of engine to rebuild if needed. All those parts can make a huge difference in cost to rebuild correctly... So my point is, how can anyone give you an accurate rebuild estimate without knowing whats needed in rebuild.??? Only way a shop can give you an estimate without tearing down engine themselves is to make their estimate so expensive it can cover every/anything thats needed. This is a common practice, that imo is not fair to customer or shop,,, all depending on the unknown exact core engine condition of who gets 'shafted'. Or shop can low ball you just to get you in there then once they start rebuild (with a deposit ?) they start listing problems with your core that bring up the price to astronomical amounts... jmo

This type of extensive engine repair is not done overnight . It takes quite a bit of time, so you have plenty of time to do your research before making the decision... Personally, at this point, I would really want to know more about "the root cause of failure"...more than anything else...I know I"m in the minority on this as most will want to know the total end cost .....but to me knowing the root cause effects the end cost in many ways ....( I don't do the cookie-cutter or all-or-nothing methods on my own engines) BTW beautiful car !!.. I hope you save/repair it !!!

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Excellent advice. Thank you

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Thank you for this detailed answer. The price is okay with me; there is no other Porsche I could replace with for 25k, so why not? It is a forever car for sure. Do you have any opinion on Slakker? Feel free to message me if easier. Thank you again.

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But that is the thing, you can't know the root cause until you take the engine out, disassemble it to at least being able to see the pistons, or maybe the crank shaft (by then everything has come off). No shop would want to do this work unless there is a good agreement that they would be the one to rebuild it, they have the space to store the car and its bits for an extended amount of time, and they have a deposit to pay for the 20 hours it takes to remove and disassemble the engine.

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....and that's why the "root cause" is missed so many times...., because we are already moving the focus "off" the root cause" .. and on to other things...($$)

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@acd683 check out this thread from Slakker and their YT channel. There are in Oklahoma, and are doing some cool stuff with M96 engines! https://rennlist.com/forums/996-foru...o-results.html

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@Porschetech3 I would dig in further too in the same shoe. what would be your suggested approach to RCA the low leak down results? Maybe this answer is better in the OP�s original thread?

Robert at Auto Strasse in Costa Mesa is a superb diagnostician, honest and knows these engines. Old school excellent mechanic. Just a happy customer, no affiliation.

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thank you. My Porsche shop subcontracts to them. I will speak to Robert this week.

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My friend owns Vision Motorsports. He has rebuilt engines on the self or you can get something custom built. Highly recommended as well as Tony at Callas Rennsport.

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Well, so far everything has been way to vague for me...No real concrete evidence of anything to get your teeth into ...A strange noise that comes and goes..( and only got to listen to for a few seconds) .. Mysterious metal shavings in the cylinder that I can't see in the pics ( that would be very uncommon even if they are there) .. Metal shaving in the oil filter that were first said not to be there but now are and no pics...And now a leak down test that has 10-20% variation on TWO cylinders .....( strange to have two cylinders to fail at the same time...). If It were my Sons car, I would call the shop and ask if the leakage seen on the Test was getting past the rings, intake valves, or the exhaust valves. Then I would ask for a Compression Test ... Then I would probably tell them to put it back together and do a Blow-by Test just to see if it passes or not ... So, at this point, unless the pic of the filter showed enough metal shavings/particles to condemn the engine, I would advise him to take it for a second opinion... just my .02cents

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As stated on the other thread, to be clear: cylinders 4 and 6 failing at 30% the remaining cylinders are failing at 20-25% I am going to ask for more info about the leakage points

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Mutual friends have spoken to Martina and Dwain for me, I am calling Dwain today

Magnetized metal debris

I am not sure from the way they cut the filter if the metal shaving is actually from the engine or from the cutting of the filter housing.

They cut the filter housing with a cutoff wheel in a dremel? Oy vey obviously the filter is full of metal! Have them put the car back together and take it to a place that knows what they are doing!

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Yeah I heard ya when you said 4 cylinders had failed with 20-25% leakdown an 2 had failed with 30% leakdown . But that doesn't explain how that happened just driving home from dinner in a Chill manor...( big question mark) And now I see why there there was confusion on whether or not there is metal in the oil filter...There are tools that cut the filer cleanly so that the Forensic Evidence is not contaminated with the very mineral that is to be analyzed.....( must be their first time to do this ) Look, you don't need a reason to want a new bigger fresh engine with more horsepower, if you want it, get it ................It's just that Failure Analysis has been my forte for 50 years and what started as Missfire and SAI Codes with a tapping noise that comes and goes, has blossomed into condemning the engine on very shaky evidence...

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I really do appreciate your guidance. I have asked them to please open the filter now cleanly and examine the rest. I sent a YouTube video on how to do it. Suffice to say; I am angry. that said, yes, evidence is contaminated. Can�t put that genie back in the bottle. Not sure how to get to root cause without beginning to open engine up.

I remember you saying you sent a used oil sample off for analysis. That should help piece together a clearer picture.

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it's in the mail but presumably will take 4-6 weeks (at least that's my past experience with Blackstone) edit: I am now also doing a rapid sample through speedDiagnostix

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The race is on!

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I would run as fast as you can from that shop and find one that knows what they are doing. Specifically, find a Porsche shop that is a known expert in the M96.

As much as I agree with @Porschetech3 regarding wanting to know root cause, the end result will probably be the same. The big differences might be how much head work is involved and if the crankshaft needs replacement. In dollar terms that matters but the check is already going to be big. If the heads are okay you could go with a factory short block, which might be the least costly. But still costly. I would not trust the shop you're at to take the engine apart any further. I would not put an M9x engine back together with the old cylinders still in it. Nickies (or their Hartech equivalent) or a fresh short block are the only practical choice IMO.

I never did see the bling factor in converting a 996/997 to a spin on metal housing filter. The factory paper filter does not take more than a razor blade to disassemble.

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Agree... Seems once the IMSB Solution came out needing a high pressure oil port, many thought the spin on adapter was the way to go with or with out the Solution installed. Not me. I like the canister. Every oil change the Canister forces you to look/clean the inside of the canister where all the debris that can't get thru the filter ends up. Also you get a good look at the filter each and every oil change without a tedious task of cutting apart/handling a sharp metal spin on filter. Not sure a little more(microns) filtering ability or a little less makes much difference in the problem prone m96 oiling system, as the filter is NOT causing oiling problems, thats for sure. Actually you're adding a unneeded potential oil leak with the adapter. The bypass can be used or disabled easily on the canister. Now if you need an oil port for temp or pressure readings/logging, then the LN spin on adapter with oil ports is the way to go for for $299.

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Well,see, my thing is this engine looks like it has no debris in the oil filter, and no Bore-Scoring , those are the 2 Biggest Killers of these engines ... What if the tapping noise he was hearing is just the Cats tapping in the exhaust pipe ?? It would not be the first time an engine was replaced/overhauled just to find out it was only a Cat making the noise .... Of course a Fresh m96 Engine with 75 more horsepower will make anyone happy, I just don't like to hear people poor-mouth about not having any money to "needed upgrades" ...

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Diagnosis before treatment? How logical.

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While I am not thrilled with the approach, at the end of the day here is a list of knowns: -the check engine light was flashing -the flashing CEL was accompanied by a horrible knocking, mostly replicated in videos on my original thread. -there is metal debris in the cylinders -allegedly, cylinder 2 has a crack -allegedly, there is metal in the filter, though the sample was contaminated -my cylinders all failed the leak down test from between 20-30% I have consulted with several of the foremost professionals/experts who are regulars on this forum and in the m96 world though I won�t put words in their mouths and directly cite them on this thread. It�s been strongly suggested that this is rod knock, and whatever has caused the knocking is likely now severed and sitting in the sump. Yes, we will be checking. That said: The car is being brought to another state and we will check the sump and begin tearing into the engine. At the end of the day, I�ve chosen not to wallow in decision paralysis and tow the car from shop to shop soliciting opinions. I�d love to know root cause, but I will engage a rebuild either way because 1) I thankfully can, and 2) I want this car forever, and I�d rather enjoy it in a perfect state now than wait for this to happen again.

Big Baller move !!! I've been there done that ...You will be happy with the extra power !!! Honestly if all that is true about your current engine,( I still highly doubt it ) I don't see how it pulled itself out of the driveway .... But I'm an Old Retired Porsche Tech ,I bought Sally 17 years ago with the engine pieces in a basket .....I bought a " Condemned engine" from a reputable shop in Atlanta for $2000 and spent $200 on an internal repair and another $250 for gaskets seals ect, and have put 100k miles of hard service and Track Miles on it ... It has only14.5 LPM blow-by and over 110 PSI oil pressure cold...Here is the recent Oil Analysis on it ... I have rebuilt the original engine 17 years ago and it is still on the engine stand awaiting its turn at Service ... I like to get ALL the miles out my stuff at this old age ..... I have since bought 2 more "condemned engines" for $3k each that believe just need minor repairs I just have them stored/stacked ...At my old age I can't stand to see engines rebuilt that don't need it ,, there are plenty that genuinely NEED it for that .. Anyway , good luck !! I'm sure you will be documenting the process ..

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I don�t think they make em like you anymore! At least, not in my experience. Yes more info and details to come.

This 996 engine with two cracked cylinders drove itself on to my lift.

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Two cracked cylinders at once !!! Me guessing hydro-lock from failed AOS ??? ( did you test the AOS post-mortem ? ) Just one of the the things that bothers me about the diagnosis on the OP's engine is the "leak down test ".. Its well known that the cylinders/rings is the highest wear item in any engine, That said even then they last 300K ,miles before they "wear out" ...Even when abused they will last 150K miles on any engine and will still run and have power with 50% leak down..( if no overheating events ) .. So for there to be a "failure" at 57k miles it would have to be caused by an unusual event ...like overheating/hydro-locking ...not just a casual drive home from dinner...

If that much leakdown is actually true I would suspect something caused the timing to shift a lot resulting in piston to valve contact and bent valves.

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interesting there were not timing issues shown on the PIWIS

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The thing about Leak Down Testers is that there is no "Standardized System" , All Leak Down Testers are not the same. Some use high pressures some use low pressures, some use a .040 restrictor some use an .080 restrictor and some use a .0xx ? restrictor . Some have 1 gauge and some have 2 gauges, so when someone says 30% leak down, the question is 30% of WHAT ? ( 30% of 15 LPM = 5 LPM which is not too bad.....30% of 200 LPM = 60 LPM which is a LOT of Leak Down !! ) That's like someone saying they lost 30% in the Stock Market yesterday, but they only had $100 in the Stock Market so they lost $30..., now, if they had $500k in there they would have lost $150K !!! I was Top Trouble-Shooter in the SouthEast for FoMoCo for 2 decades in the 80's-90's so I question everything until I find the "Smoking Gun " ...

I do all my leak down testing with the 2 gauge device that's used for piston airplane engines. I believe the orfice is standardized by AC43-3. 80 PSI in and whatever out.

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Your right ...they haven't made a model like me for 69 years..... We are a dying breed .... The ICE Aircraft Community is a unique group of people who I see as a basic benchmark in ICE design ....They are all about reliability and dependability .... My Dad flew Crop Dusters back in the 1930's after having dropped out of High School at 16 years old to join the Navy for WWII, after WWII he then finished High School and re-enlisted for the Korean War , then Cropped Dusted in a Piper Cub until he was grounded for Barn Storming...lol..then spent 33 years working for US Steel.. The reliability and dependability in ICE Aircraft comes from low RPM engines and redundant ignition and fueling systems and gauges out the wazoo for the Pilot to monitor all aspects and can see a problem in the making Before it becomes Catastrophic ... Redundant ignition systems means if the complete ignition system fails, just flip over to the other and keep going ( but repair asap) . Redundant fuel systems means if the complete fuel system fails, just flip over to the other and keep going ( but repair asap) ,,..Most have dual tanks and at least two fuel pumps... Gauges out the wazoo means the Pilot can monitor oil/fuel pressures and all temperatures and watch for any problems heading his way... Generally speaking when "leak down" is over 25% or oil consumption is more than 1 qt per hour, then is time to intervene... So, generally speaking with ICE Aircraft at 25%, most Automotive Shops at 10% and Race Car Shops at 1-3% ......and with so many variations in the Leak Down Testers themselves.....Top Trouble-Shooters only find Leak Down Tests valuable "AFTER " it has failed a Compression Test on a Cylinder of more than "10% lower Compression ie. one cylinder with 150psi and all others with more than 165psi " just see WHERE the leakage is going ... So with Leak Down generally high across the engine, I don't count that as a "failure", It could be just bad from the beginning beak-in or from "over fueling"..which could also explain the missfire codes . The picture of the cylinder showing no Bore-Scoring, but some debris said to be metal shavings, but to me looks like simple Carbon breaking off when the spark plugs were removed.. The picture of the oil filter only shows debris from wrong procedure of cutting the oil filter apart.. The " only Credibility " I give to anything is the tapping/knocking unusual sound, that you heard and recorded for a few seconds that could be from anything, like a piece of Carbon on top of the piston that blew out the tailpipe or a loose Cat causing the noise..... Once you disassemble the engine you can't just put it back together to spend more time confirming the source of the unusual noise ..

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I'd like to add the results of the oil test that I received from Lake Speed today. No elevated metal levels detected! Please see attached, Cam deviation is 0.0 Multiple cylinders running rich (-3 to -6 adaptation values) i drove the car for 35 minutes tonight. Once I stopped, while warm, this is the tapping sound: https://youtube.com/shorts/16mJG5OlKJ4?si=CAYYRA1exi4HlUmM

So no noise for the first 20-30 min ? Did the engine run perfectly smooth and quiet for the first 30 min ? What does the oil pressure look like cold/hot and also any fluctuations in oil pressure while driving and,/or left/ right turns ??? ( I'm trying to rule out air getting into the lifters as a possible source for the noise ) Glad you haven't let them tear the engine apart yet !! 👍

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Always good to get a solid oil report! I know your indy did a number on your oil filter, but did you ever drop the sump to see what was sitting in it?

Agree, good thing you haven't had the engine taken apart yet. Could it be that 1 cilinder is blowing from between cilinder head and exhaust flange or 1 spark plug is loose? Also interested to hear the answer to the question asked by GC996: was the oil pan dropped and what did that show?

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I got up early and went for a drive on empty streets. Everything seemed normal as I was warming up: idle around 1.5 bar, just under 5 under a load. I recorded these two videos while warm to track RPM vs. oil pressure. Seems a bit low But not sure. When I rev it up, oil pressure seems to fall a bit. Not expected? RPM v. Oil Pressure #1: You Tube RPM v. Oil Pressure #2: You Tube Additionally, at warm idle sitting for a few minutes, the car really sputtered at one point, felt like it was about to die. But it recovered and resumed normal idle. Wondering if I should get some injector cleaning in there and just rip it around a bit? As of this morning, the CEL went OFF on its own for the first time. I proceeded to clear the codes and will see if they come back. The sump has NOT yet been checked.

Ok !! Glad you got your car away from that Shop...So many Shops are so busey with Routine Maintenance ( brakes, tires, clutches, oil changes, spark plugs, oil leaks, shocks,suspension, IMSB, RMS ,AOS, ect) that are just not great at Trouble-Shooting ... Good thing you listened to me and didn't let them tear your engine apart because the longer video sounds like your engine is fairly healthy and not yet ready for a $30K Intervention ... BUT your are not out of the woods yet , (DO NOT BE RIPPING AROUND ON THIS ENGINE YET ) ....Your Video shows the oil pressure dropping at above 3000 RPM , This is your cause of the noise that appears after the engine is fully warmed and driven above 3K RPM's .... The drop in pressure means that air has entered the system and is filling the lifters with air and causing the noise ( and also will cause misfires)... The focus now is to find and fix the cause of oil pressure dropping at above 3K RPM ... 1 Could be caused by a blocked pick-up tube with silicone sealer..( drop the oil Sump and inspect) 2 Could be cause by a failed Scavenge Pump ( R&R both Scavenge Pumps and inspect) Both of these are easy to do and well worth the time/effort to avoid an unnecessary $30K overhaul .. My Prognosis is a full recovery WITHOUT a Major Surgery .....

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thank you sir! yes the drop in oil pressure sure felt like a flag to me. I will share this with my shop. MUCH APPRECIATED. I will be seen there Tuesday 9/23 so stand by for updates.

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Another thing ... Have your Shop ( hopefully not the one who cut open the oil filter) document the "orientation" of the Scavenge Pumps ( with a pic) before R&Ring them .. There are 4 possible install positions on the 996 Scavenge Pumps, but ONLY 1 position is correct .. You haven't given any background on this engine, so if the engine has had any repair/service that would require Scavenge Pump removal, this could be an issue.. ( I have seen the pumps installed incorrectly before many times and a couple of times it wasn't discovered untill "months" later...

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i have all service records since new and am fairly confidently it�s never been replaced but will share this info!

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@acd683 Well ,any news from said visit yesterday?? ^^^^ 9/23/2025 You have an interesting case Grasshopper ... Hopefully they pulled the Sump and found silicone blocking the oil pick-up tube and cleaned it out and everything is fine... Or they found one of the Scavenge Pumps miss-oriented or damaged and corrected that and everything is OK ..

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still awaiting final confirmation but he ordered an oil pressure sender unit to install�apparently a common failure point and he wanted to start there based on his test drive and initial inspection. I�ll follow up when I know more! He�s also doing the leak down today or tomorrow.

poke - any update?

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I am supposed to pick the car up tomorrow. The new oil switch is in, and the car passed a leak down test. Blackstone analysis also came back perfect. Still a little unsure what caused the misfires...but getting new plugs and coil packs, too! Car is apparently running great!

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Did I save another m96 through my questioning things.....?? Any pictures of the Sump? Can you post the Oil Analysis ? Somehow I knew most of the "expert advice" and test results you got were bull****..... but I still want to know the source of the noise.....

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Yes, here's the Blackstone analysis. The SpeedDiagnostix was similar. I'll be honest, I am a bit concerned the issue may not be resolved, only because I know the sender is a sensor only, it doesn't CONTROL the pressure, etc. So, DID my pressure drop when I turned? And will it happen again? I am hopeful this was an ignition issue, and new plugs and coil packs will be the fix. I've read that combustion ticking from misfires can happen at low RPMs and smooth out as the engine revs up, and are often confused with lifter tick. So, maybe that? I will drive it a lot tomorrow evening and see how it all goes. My mechanic says he feels very good about it,

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Hi - I had pressure drops when turning (just around simple easy corners). It was that my scavenge pump was installed upside-down (Another PT3 save.) Takes 10 seconds to check that they're installed correctly

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Hi! Definitely happy to check this, but here's why I don't think it's that (someone point out the flaw in my logic if there's something apparent). This isn't a new-to-me car, and the pumps shouldn't have ever been touched while in my care. I also have 20+ years of service records and nothing to indicate they were serviced by the first owner, either. I have owned the car for 5.5 years and put about 15k miles on it, approximately half of which is canyon driving. So...wouldn't an improperly-oriented pump have presented a problem before now?

Yes I still think that your original "concern" ( engine noise) has not been identified and the root cause established and repaired...I think it will come back again and all the smoke and fire from the Botched Tests and misdiagnosis has drawn the focus away from that goal... Yes i think the original noise concern was air in the lifters causing lifter noise...... Air gets into the lifters when there is a lose of pressure....( you probably weren't looking at the gauge when it happened)..... The pressure lose can come from several places..as mentioned the scavenge pump orientation,also simply a broken drive on the scavenge pump, the pumps should be removed for this check.. Also a collapsed oil filter will cause a oil pressure drop... You haven't said whether the Sump was dropped as it should have been, and what it looked like in there...Were there anything in the pick-up tube? was any strange bits in the Sump?

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I've got the car back now and am going to continue to drive it until some indication of a problem presents itself again. My mechanic didn�t check the sump but if it ends up going back I�ll make sure it happens!

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Keep a VERY close eye and ear on the oil pressure for the near future.... It is possible that they inadvertently cured the problem and don't even realize it ....Like by replacing a spin-on oil filter without cutting the filter open to inspect for collapse...ect ....A few hundred miles should tell-the -tail .... Good luck !!

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here�s a question for you, PT3. I�m attached my cam deviation numbers. My googling tells me some of these numbers are a little out of whack. Might this be a piece of the puzzle? To be honest, I am alarmed at these numbers, specifically -7.5 on C5 (I believe this is intake cam timing at idle on bank 2?). It seems I am in the warning stages, and if I don't do a timing service soon, I could be risking a jump?

I can tell you FOR SURE that your cam deviation is not causing any of the concerns we have covered on your engine.... Also I never trust ANY values other than the ones from PIWIS or Durametric Diagnostic Tools....All others have proven to lead people down the wrong paths by giving erroneous info ..

Reading about the symptoms of excessive cam deviation, they don�t stray far from when I experienced August 31st that started this whole mess for me. Multiple misfires, loud rhythmic tapping, flashing CEL, and rough idle.

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Nah.....I have purposely deviated Cam timing as much as 10 degrees in both directions just to change the characteristics of the Power Curve... Advancing the Cam timing adds Power to the lower RPMs while gives up Power in the higher RPMs....and vice-versa.......Retarding the Cam Timing will add more Power in the higher RPMs but loses in the middle and lower RPMS... Some people think those numbers are written in Stone....they are not ....The deviation numbers and Spec are to" judge" if the chains have worn past a certain point (3%) and to maintain Emissions Specs..( CEL Code) Changing the Cams to X51 Cams or to Schrick High Performance Cams changes the Cam timing and "deviation" ( and duration and lift ) but the "deviation" is set back to zero ( even though it is not the same as it was in a Stock Cam .).......

Bank 1 is the bad deviation

Always is....

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haha I appreciate your confidence. Thanks again for your help! I�ll update you if something happens

Oil pressure is still too low. We are dropping the sump on Friday.

My cam deviation bank 1 has jumped to -12.02 and three cylinders are misfiring

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@acd683 So what did it look like in the Sump?? Where are the pics ?? And when you say "oil pressure is low"..... do you mean as in" it is never normal' ? or do you mean...It is normal most of the time except in certain circumstances such as ........?

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that appt is tomorrow its Rarely above 3.5 now. On turns it drops to 1 when warm. This never was the case before August 31st event. The oil pressure behaves the same as it did in those YouTube clips I uploaded. My pressure just sucks. For 5+ years I was pinned to 4 or 5. Until now. I am leaning heavily into the idea that this is variocam pad wear

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To me it sounds like I mentioned at the very first....Air getting into the oiling system .. Either the pick-up tube is blocked or the Scavenge pump ( pumps) have failed..... These are very easy to check ... Hopefully you haven't hurt it by taking so long to Test it ...

Sorry to be reading about your oil pressure troubles @acd. Hope it's an easy fix once you find the culprit. I noticed a similar noise after a drive yesterday in mine. Oil pressure fine. My spark plugs were changed one year ago, just about to have a six month oil change. My immediate thought is a sticky lifter. Currently on Porsche Classic 5W-50. You Tube

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So just to be clear, you think a bad (and worsening) cam deviation of now -12 is not part of the troubleshooting matrix?

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yes agreed on the lifter. We changed the oil and added ceratec and the noise hasn�t returned.

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What I am saying is that the deviation may be part of the collateral damage but not the most direct Trouble shooting path to the most serious Symptom... The Scavange pumps are driven by the timing chains and gears that are also responsible for the cam deviations... If the Scavenge pumps, are locking up it will placemore stress on the timing chains and the IMS gears, and can causethe gear to slip and more cam deviation... And removing the Sump to inspect is one of the easiest and fastest diagnostic methods there is on the M96 to get a feel of the engiine..

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thanks for this, screenshotted and sent to my mechanic

What PT3 says (re: scavenge pumps) makes sense to me. When my bank 1 was installed upside down (i.e in effective) I found turning right I was getting pressure drops at what I would says was 0.3 G turns.

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Photos to follow but there is significant dark plastic debris in the oil pan and in the screen of the oil pump that my shop believes is consistent with the variocam pads disintegrating.

pictures? The variocom pads are not dark ...

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they aren�t dark new. They darken significantly with age and use. The chunks are brown and are consistent with worn pads. I saw the pictures on site and should have them electronically tomorrow.

I hope your Shop pulls and checks the Scavenge Pumps... I'm still waiting for the Root Cause of the " loud tapping noise " that has now subsided....I would not call it "OK" untill that smoking Gun is found .....

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read this elsewhere:When the Pads Deteriorate Over time (especially after 50�70k miles), the plastic pads can: Crack, crumble, or delaminate, often due to heat cycling and oil degradation. Leave gaps or missing material, so the chain loses proper tension at certain angles. Allow the chain to slap the metal housing or actuator bridge � that�s the �slapping� or �tapping� you hear. Slapping or flapping sound at idle or low RPM (especially when warm). Often on one bank (commonly Bank 1 in M96s). Can mimic chain rattle or tensioner failure. Sometimes disappears at higher RPMs when oil pressure stiffens the tensioners.

^^^^^^ All this is true ..... BUT those things don't "fix themselves"........ as in not making the noise during/after multiple 20-30- minute drives... Also just my old *** ear that has listened to engines for over 50 years....it didn't sound like chain slap or chain rubbing across a metal pad holder.. But maybe I should just keep quite and wait to see...who knows I could be wrong for twice........

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@acd683 How's the car?

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i too would like to know your progress, I have a early red aero coupe and all I can add is if you like your car the spec is getting more and more desirable $$$ . I have another 996 that when needed an engine rebuild is possible due to the PTS yellow option that I love and be willing to invest in keeping the car up and running. Good luck going forward. Rich

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car is great. It was indeed the variocam pads failing and disintegrating as reflected in the cam deviation. thank you for asking do you still have your amazing ocean jade 996?

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Awesome to hear! I too was following for an update on your issue! You dodge a huge bullet. What was the ballpark cost for your shop to replace those pads? Pretty sure I should start preparing myself for it, and I am also in SoCal.

No sold the Ocean Jade cars years ago would love to keep them all but funds and garage space controls my world 😀 Rich

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ill get back to you on the cost shortly