1 rebuilt engine, 1 month, and 325 pictures later

It's been a month long journey into the depths of my 1999 996 C2 M96-01, but I am finally there and the car is on the road again! If you want to skip all of the boring commentary and head straight for the annotated pictures, then here is the link: https://picasaweb.google.com/1085493...12361/Engine02 (the email address associated with this account is not monitored, PM me or post here if you would like to send me a message) Some commentary about the process for the readers. PROBLEMS 1.) In the past 5,000 miles, oil consumption had gone from about 1 quart per 1500-2000 miles to 1 quart per 1000 miles. Still within Porsche spec, but such a rapid increase was worrying. I also knew that there were a ton of leaks that needed to be addressed, such as the spark tubes, camshaft covers, cam solenoid cover, AOS tubes, oil filler neck, and on and on and on. However leaks aside, the big indicator here that something was afoot was that bank 1's tailpipe was accumulating soot and producing purplish smoke on startup and high RPMs much more so than bank 2's pipe which was not exhibiting these issues. 2.) The oil pressure was fine at start-up, 5 bars. However when the car was warm it would fluctuate very slightly a few points in either direction of 1 bar at idle. Sometimes .8 bars. Cleaning the sender terminals did not help. I did not drive the car very long with this condition. In fact, barely at all before I decided to do this work. You don't want to mess with low oil pressure. This problem and the next one were what really got the ball rolling on this endeavor. 3.) There was an increasingly worsening knocking from bank 1 (1-3). The knocking would "seem" to stop after about 30 seconds on cold start, and I thought that this could be lifters or tensioners taking their sweet time to fill up with oil. One time the ticking lasted for 5 minutes. That really put the icing on the cake for the decision. After much Internet research, I determined that it could be stuck or collapsed lifter noise, because I couldn't tell whether it was coming from the top or bottom and that it would seem to go away after the car had oil filling the parts (but it was actually still there). In the back of my mind I also had thought that it could be oil pressure, blockage, valve guide, still could be worn rings, or perhaps issue with a chain tensioner or variocam unit as well. (after researching more and using the screwdriver stethoscope trick, I discovered that the knocking was present in cylinder #2, in the bottom end, but it was also present in #1). The exhaust valves in cylinder #2 were most heavily coated in carbon as well. Eventually, this realization and discovery later that the lifters were OK from my non-professional mechanical knowledge prompted me to pull the heads and have a valve job performed by professionals. ACTION Each problem individually above one might address on the surface by changing or swapping spark plugs, coil packs, and oil viscosity (which I had all done), however when those didn't have a noticeable affect on the issues, I decided to do something about the nervousness and drop the engine. A bevvy of parts were ordered. Because a lot of the parts on this car is relatively inexpensive, I decided to R&R many of the components which I had isolated before removing the engine. For example the 4th and 5th chains cost only half that of the bicycle chains I go through several times a year on my road bike. Each of the three chain tensioners were less than $100. Some people might question why I replaced both oil scavenge pumps after only 75,000 miles and 12 years of life, however in the overall cost of the project the investment was minor. I'm glad I did too, because one was not rotating as freely as the other, and no where near as freely as a new unit. An LN engineering billet hex oil pump driver and genuine oil pump spring and piston were also sourced. Waiting for the parts was actually the most discouraging part of the entire process for me. A few times I had to wait for parts from Germany which meant 7+ days. I replaced nearly every gasket, o-ring, and washer I could which was external to the engine, including some which are internal such as the valve seals (done by the machine shop) and head gaskets (can't avoid doing that or the bolts if you remove the heads). In hindsight I should have ordered the ARP studs for just a few hundred dollars more than the stock single use head bolts. I ordered 24 new "BMW" INA lifters, in case they were some of the source of the problem. Also in hindsight, instead of ordering individual gaskets and orings I could have ordered the complete gasket set, which probably had more in it than I was going to use but would have been easier (although somewhat more expensive) than ordering ala carte. WORK Here are the major highlights on what I replaced or work performed. Complete valve job was performed by Riebes machine shop including: Cleaning, gentle bead blast, and light resurfacing, vaccum and pressure test. Three way valve cut, 5 new valve guides (2 were horrifically worn - the source of the knock), new valve seals, and overall inspection for valve train components (springs, etc.). The machine shop also resurfaced my fabspeed stainless bank 1 exhaust header, it was badly bowed out in the center which plagued me with constant re-torquing, stripped threads, damaged bolts, and a lot of helicoils later. GOOD BYE exhaust leaks!!!! Head gaskets Head bolts Variocam ramps (two were heavily pitted and scored) 4th and 5th timing chains 24 new (old style) lifters LN engineering billet oil pump hex driver OEM oil pump pressure spring & piston Both oil scavenge pumps Oil pressure sender (cleaning the terminals did not help) All three external chain tensioners (all were scored) Replaced many coolant and AOS hoses New air oil separator Countless gaskets, o-rings, & washers Micro encapsulated rear case bolts Replaced water pump (oem, peace of mind) Replaced thermostat (oem, old one was lazy) Resealed and inspected oil pan 4 new lambda sensors (3 were very "slow") - killer deal from Amazon 6 new spark plugs (packs have about 20k on them) Fuel injectors sent out for test, cleaning, orings, and new filters Oil filler tube and cap New "04" coolant cap 10 quarts Castrol 5w40 Oil filter Cleaned IACV Thorough cleaning of engine exterior Cleaning of any interior or exterior part I reinstalled Thorough Intake plenum cleaning Inspected DMF and clutch Replaced about 1 quart of CHF P/S fluid Inspected polyrib belt New SAI check valve, hoses, tubing and elbows, and cleaning Repainted coolant tubes Flushed 12 year old Porsche coolant out and replaced all coolant with Peak Global using Uview Airlift 550000000000 Cam caps Ordered new RMS but didn't install because old was bone dry !!!!!!RESULTS!!!!! The results of all of the above are restored confidence in driving the car. The oil leaks appear to have vanished, since the engine is so clean it is easy to spot fresh oil. Low end torque seems to have dramatically improved on the few drives I've taken. Although I've taken it there a couple times, I haven't yet "fully tested" the high end RPM range because I'm going to give it a bit of a break in and "get comfortable with the rebuild" period first. Oil pressure now stays dead straight on at 1.2 bars hot idle and 5 bars cold idle. Last and certainly not least, NO MORE smoke at startup or high RPMs (thank you valve job). Time will tell if the soot or oil consumption returns. NO MORE ticking or knocking (outside of normal lifter and valve train noise I hear on any car). Thanks to the new thermostat the car gets to temperature much more punctually than it used to. The engine idles much more smoothly than before, it stays pretty dead level on 680 rpm - whereas before I'm sure there were some leaks in the system it would fluctuate some, the plugs were fouled too so not surprised. Warm idle numbers are pretty much dead on with the factory DME set points. Load signal 1.6 ms Air mass 20 kg/h Mat film MAF 1.35 Ignition timing 4.5 to 7.5 Spec air mass 17 gh/hr Spec air adapt 1 kg/hr Injection time 3 ms Oil temperature 207.5F (stage 1 is on, idling on a hot day in my garage) Oxygen sensing 1-3 1.04 avg Oxygen sensing 4-6 1.03 avg Range2 Cyl 1-3 FRA .98 Range2 Cyl 4-6 FRA2 .98 Range1 Cyl 1-3 TRA -0.14 Range1 Cyl 4-6 TRA2 -0.14 02 ahead cat bank 1 fluctuating .09 to .77 02 ahead cat bank 2 fluctuating .09 to .77 02 behind cat bank 1 fluctuating .09 to .71 02 behind cat bank 2 fluctuating .09 to .71 Cam 1 deviation 3 degrees Cam 2 deviation 3 degrees (was 0 before I did the work) Rough Running Thresh 10.5 to 10.1 Rough running occasional spikes to 1.5 Segment A 1 Segment B 1 Sense wheel adapt .0007 Misfire detection 0 ISSUES Not to say that my work was perfect, because I had one weeping perimeter head bolt that wasn't torqued properly, I damaged one of the coolant hoses upon reinstall (new one ordered), broke the stupid plastic AOS coolant coupler near the oil fill tube, and the oil filter housing was not torqued to spec (next time I have some spare cash I'll probably do the spin on adapter, I'm so sick of that stupid plastic housing). Bank 1 was ticking badly upon first start, I thought for the worst that I had to drop it again, but thankfully it was just a loose/bad spark connection. I also improperly routed the throttle cable and as a result the DME was confused about the throttle plate angle at first startup, and the idle was stuck at 1200 RPM. Both variocam actuators actuated properly when activated with the PST2, and power through the range is consistent and smooth. The only nagging things I am left with which I am somewhat kicking myself is noticing after the fact that the crank pulley appears to have more run out than I would like to see. I will be measuring this run out soon and investigating the possibility of a flat 6 harmonic under-drive pulley or perhaps a new engine. That and I don't think I have the timing 100% spot on, but it is close. I am also nervous about a potentially poor decision to abstain from loctite usage on the variocam actuator, lifter carrier, and bearing saddles. When I removed those bolts they appeared to be "factory fresh" oily and brand new for lack of a better term. So I decided to just re-torque them to the specific tightening sequence and value. It wouldn't be the end of the world if someone told me I did that wrong and should really consider removing the cam covers again. At least this time I would be able to do the work faster and with much more confidence. DISCLAIMERS I AM NOT A MECHANIC. I am a computer professional, and have done most of the work on the cars or boats I've owned or used for the past 20 years. Some of the things I comment on in the photo gallery might be done "incorrectly" or be appalling to some who are in this trade. But, I have to say it got the job done and I'm not afraid to drive my car anymore. THANKS First and foremost rennlist and renntech are perhaps the best sources of useful information you can find, since there is not a ton of info about these engines elsewhere, unless you have the money to pay for one of Jake's seminars (which would be totally awesome) or are a Porsche employee. There are several great "DIY" engine drop websites as well, http://www.nutrod.com , http://986fix.com , and http://www.oz951.com/public/enginedrop.htm . http://101projects.com and Wayne's Boxster book is great as well for M96-01 info, especially for summarizing the cam removal DIY - however seemed somewhat "incomplete" to me since it is light on documentation for a few critical things out such as ensuring proper timing procedure and torque settings are carried out. In the end, nothing can replace the authentic work shop manual. I wouldn't even try to attempt any of this without access to that and a Durametric and/or PST2. Thanks to all the suppliers, Bob @ http://www.sunsetimports.com , Henry @ http://www.porscheoemparts.com , http://www.pelicanparts.com , http://www.rmeuropean.com , http://www.4wheelsautoparts.com , and http://autoatlanta.com . And certainly THANK YOU PhillipJ, Dharn55, Loren, Don and crew at Riebes machine shop, Dr. Injector, and anyone else who provided any help including those that helped fund this project through the sale of some of my parts! Now it's time to take a drive!

wow, good job. Was this your first engine rebuild?

Awesome work man. Thank you for the DIY contribution to the site! Enjoy the 996's new lease on life, and I wish you hundreds of thousands of carefree miles.

I am in awe. Though I don't understand most of what you detailed in your photo history ( I don't wrench), I followed the sequence to the end. You should be proud of the attention to details and thoroughness. Congrats!

Very impressive. She's good to go for a while now. Enjoy, you earned it!

Great contribution to the forum!! One question. Doesn't this seem like excessive wear at 75K miles or did I get that wrong?

Great job.. I would certainly use a proper cam timing tool, the tool forces the cams into position and holds them perfectly and tightly during the tightening procedure of the drive sprockets. Without doing this, you will never get it spot on without using the split overlap method and treating the engine like an aircooled 911.. The problem is the cam timing numbers that allow this to be done are not published anywhere. This was one of my first challenges, back before cam timing tools were even available. You accomplished a DIY task that few have attempted and fewer have successfully completed. It sounds like you did your homework and took your time. The pictures depict a 75K mile M96 engine well, thats almost exactly what we see time and time again, yours is absolutely text book. We had most of those special order parts from Germany in stock.. I really do need to get my web store up to date. We have to stock a lot of this stuff for our procedures and engines.. Getting parts can be a bitch, its one of the achilles heels of working with this engine. It is much better than it was prior to 2008 when literally everything had to come from Germany... Thats why we started building so many of our own parts.. It really sucks. A couple of questions: -How did your cylinders measure up for ovality and taper? Especially the #2 and #5 cylinders? - It doesn't appear that you split the crankcase from the parts list, is this correct? ( I didn't see piston rings, bearings or carrier bolts and thrust shims on the list) Glad its performing well.. These engines are only difficult to work with because everything is sequential and procedural. Learning the correct sequence of assembly is the key to making the job simple. Have fun!

Nice work. I look forward for the day (later than sooner) that I can tear into one of these motors. My MK1 with 100k is still running strong though with no leaks or issues(knock on wood). I may have to replace my chain tensioners soon since I get some minor chain noise somedays on start-up.

BTW: GREAT pics!! Thanks for the post!

Excellent write up and great job! Thank you very much for the extensive pictures and documentation. Very much appreciated.

Great pix, congrats!

I have been following your rebuild and questions with commanding respect. My favorite picture from the threads is this one with war wounds.. Way to go! https://rennlist.com/forums/8704303-post3.html

When all was said and done was the cost anywhere close to purchasing a remanufactured engine and installing it yourself? This is something I've considered doing in the future as my car is up to 107k miles right now. No problems but just preparing for them if they do happen.

What a great write up! I really enjoyed pouring through all the photos and details.

Very nice and well done. This is going to turn out very nicely. Keep us updated with pictures and info. thanks,

Great post, much appreciate you taking the time to detail your process. I plan on doing a rebuild for a back up motor for my race car, but lack the time and space to start.

Very nice writeup! I am about half way through the pictures. You are very thorough! Incidentally, I too would like to know more about what your total costs were on this project.

Quite entertaining. Thanks for taking the time to take all the pictures!

What a difference after you cleaned the outside of your engine, replaced so many components, gaskets, plugs, AOS etc. A great pictorial of all your work and no doubt a future benefit to anyone interested in doing the same. My hat is off to you, you must feel a tremendous amount of satisfaction by doing the work yourself. Thanks for the slide show and your explicit documentation.Now, go take your rebuilt Porsche for a long drive.

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Thanks again for all of the good words everyone !!!! If feels great to be driving the car again. When you're away from it for a month you start to realize why you bought a Porsche in the first place. 1.) I did not measure the cylinders, only went over them visually and could see very few imperfections for 75k miles. Then again, I am not a pro. I suppose if they are not within tolerance it is only a matter of time... and perhaps another mistake at perhaps throwing money at something that might not be worth it down the road (more on that later). In hindsight I probably should have done a lot more, but the costs were starting to skyrocket. 2.) Correct, I did not split the case, but I may have to revisit this at some point due to a potential issue that might be present with worn rings (if the soot and oil consumption returns). And a potentially worse problem with bearings or shims and possibly even camshaft. Unfortunately (kicking myself) I didn't catch this until I had reassembled (front and rear seals dry as a bone), but I need to measure the run-out on the crank pulley since it appears to have a slight wobble. I am hoping a harmonic under drive pulley and new DMF could compensate for a potential problem and extend it's useable life, although I'm not sure by how much a damper could help, or if it is worth it in this engines case? Although it was great fun to drop and tear apart and I would do it again in a heartbeat - I suppose if the crank shaft has a problem I will just drive this car until it explodes, because I can't see spending another $6000 on it for that work - which brings the total spend closer to a replacement (more on that later). No, I rebuilt my boat's motor due to blown head gasket about 2 years ago. I've also been inside VW, Ford, and Chrysler, but I am no seasoned pro by any means. In short, not even close, but here is some narrative about the costs involved should you decide to do something similar. COSTS I spent $3000 in parts and $800 in labor. I was able to offset that by $1700 through the sale of some misc parts I had stock piled or stored and was meaning to sell regardless. Not calculating the sold parts original value (<cough>, double in most cases) since those things were already done and paid for years ago, that brought my "total out of pocket" down to about $2150, or $150 over my original budget. I did consider a new engine. However, you can't get one for $2000. I also considered http://www.renegadehybrids.com , but some people would scoff at the idea. I also considered nickies for $4000, but at that price plus the $3500 above (and more), it would put the total spend much more closer to a replacement. Not to mention why do it yourself when for just a little more you can have the best in the world? (more on that in a bit). However I finally decided that I want to give what I have already a shot at a new lease on life - if it works out, which it seems to thus far - will be the least expensive way to get back on the road. If I really screwed up or poured money into a heap, I'm only out the $2000 it wouldn't be the end of the world, and there would be other options available ... which would be inevitable (or perhaps even more costly) anyways if I continued driving the car in the state it was in. I guess you could say I "gambled" a little bit. Time will tell, I suppose. I'm not looking for brownie points here, but when you do this on your own and tally up the numbers as you will see, this goes to show you that Flat 6 REALLY DOES provide value in what they do... for actually very little labor costs (albeit I'm sure they do make a little on parts) - there are no "hidden costs" there. For example. The only NEW or USED engine I would consider buying would be from Flat 6. IMHO, you are trying your luck at one of those $5000 ebay rebuild specials from motor meister or from a breakers (who charge significantly more and that is just pulled out of "some car"). Currently Jake's "least expensive" option is $9000 for a rebuilt and certified 3.4L. While that would give the car a new lease on life, I could not justify spending $10,000 on a car that might be worth $20,000. Sad, but true. Thet whole IMS debacle plus the tanked ecomomy does not bode well for the new water cooled generation. Somewhat kicking myself I didn't pull the trigger on a 993 which I was also eyeballing before this, but you live, you learn. Here is the cost break down for those interested: RESEARCH I forgot to include these invaluable threads in my original post but these are MUST READS if you plan to do this on your own!!! http://www.pelicanparts.com/techarti..._Tensioner.htm (a little light on documentation for CRITICAL things such as timing and torque settings) http://986forum.com/forums/showthread.php?t=26418 https://rennlist.com/forums/996-forum/637412-making-9611-cam-holding-tool.html https://rennlist.com/forums/996-forum/641790-issue-with-p253-camshaft-timing-tool.html https://rennlist.com/forums/996-forum/508893-qustion-on-camshaft-allocation-tool-9612-a.html https://rennlist.com/forums/996-forum/594122-how-to-set-cam-timing-on-996-a.html https://rennlist.com/forums/996-forum/510492-intermix-repair-camshafts-threaded-plugs.html https://rennlist.com/forums/996-forum/623466-lifter-noise.html Also thanks to http://www.pedrosgarage.com and http://p-car.com

awesome thread! you did a heck of a job. don't be suprised if your inbox becomes inundated with rebuild requests for assistance and guidance.

Great job, great info, the best demonstration of what an enthusiast forum is all about.

Excellent writeup and info! Congrats on the success!

Now that you're up and running, let's go for a drive sometime.

wow, loved the pictures, it's nice to see that someone documents what they are doing You did dig deeper than I did, I did not remove the heads nor did I change the lifters... Well new lifters and oilpump are on the shelf, waiting the time to change those...

Did I miss the part where you actually rebuilt the engine?

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Well, if you read the first post (and my second reply) you would see that I did not crack the case. However everything from the case outwards, it's all in the picture album link - from engine drop, to dis-assembly, to reassembly. About the only part that is light on pictures is raising the engine, but it was pretty anti-climatic and I was too busy to take pics. In fact raising it seemed much easier than dropping and there aren't a ton of things to connect once you get it up in there. Also I did not do the valve job, that was outsourced to the professionals with several tens of thousands of dollars worth of computer controlled valve cutting machines - however I did post plenty of before and after pics of their work on the heads.

Congratulations. This is excellent reference material. Thank you.

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That is awesome and quite reasonable! As long as the case doesn't have to be opened this seems to be a perfect option for someone who wants to tackle the job. If you did have to open the case would you have attempted that yourself or sent it away? Any idea what that would have cost? Although I would imagine if there's not a lot of oil being consumed opening the case really isn't necessary...

Incredible job! Amazing work.

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Well that would depend on what is wrong or what work you are doing. Would I have opened it? Possibly and I may go there at some point down the road if the smoke and oil consumption returns. I would also strongly consider outsourcing that work. If your crank, bores, and pistons are within tolerance and undamaged, and it was just opening up to replace rings, bearings, and so forth it would probably add another ~$1000 in parts. Of course the trained eye might see more that is wrong and would require more parts. Not to mention as Jake pointed out barely any of the specifications are published anywhere, so you are probably better off sending it out to get this work done anyhow. But to me the economics for the ordinary driver past the above don't make much sense... If it needs to be "rebored", the block would need to go out to LN for Nickies and larger JE pistons ($4000), or some alternative if there is one out there - I've heard there might be some European companies with alternatives. If the crankshaft is bad, it needs to be replaced ($3300 OEM, $5500 flat 6 billet). So at that point, with either one of those options plus the head rebuild you are well up into the ballpark or over the cost of a replacement engine (of course not one that has "Nickied"). So to me it wouldn't make sense to crack it open unless you are building a race car OR have an endless budget OR you know what you have to work with is already sound. These are just opinions though on the matter. Again I'm just an enthusiast and not and expert, so others probably have more seasoned alternative views.

Great write up and pics! Thank you!

500 Mile Report. The car is a joy to drive. So much power. Idles very smooth too. When it rains it pours though. Right after I installed the engine I tested the variocam actuators with Durametric. Both banks worked, however shortly thereafter I couldn't activate bank 1 when I tried it a second time and got a P1531 code. I ohmed out the solenoid and it read near 0. Whereas bank 2 read over 13. So out came the engine again to replace the solenoid. Engine installed a second time and I've put 500 miles on the car since. Oil consumption seems to be near zilch at this point, wheras before I would have blown through perhaps 1/2 quart at 500 miles. One outstanding problem though. Bank 1 is accumulating more soot in the tailpipe (signifigantly more) than bank 2. In fact, the right tail pipe is pretty much black with soot (I had cleaned during the rebuild) whereas the left tail pipe is basically clean. This problem was devleoping before the top end rebuild and it doesn't seem to have changed afterwards. Yeah yeah, what does soot matter anyways - if the car runs great who cares, right? But I am concerned that the two banks are developing soot at a different rate. Cylinders were very smooth when I had the heads off. Could not see or feel any imperfections (of course that doesn't mean they weren't oval, which I did not measure...). But I sorta took a gamble the purple smoke (now gone) was going to be the in heads anyways... (which several valve guides were found to be shot). So thinking perhaps the soot build up could be worn rings on one or more cylinders in bank 1 since I had just done the top end, must be the other end right? The out of spec valve guides and all the valve seals were replaced during the valve job (not to mention 3 way valve cuts to ensure perfect seating)... so pretty confident where the air would leak out... I decided to do a leakdown and compression test. Warmed up the car and proceeded to get the results. Much to my surprise... Leakdown (in each cylinder the air was leaking through the oil filler tube indicating worn rings, not a hint of air from the top or bottom end). 1 = 23%, 2 = 24%, 3 = 24% 4 = 25%, 5 = 25%, 6 = 26% Not too bad for an engine with 75,000 miles on it. Not that good either, but probably not a reason to tear into it again at this point, looks like the rings have a few more miles in them. At least it shows even wear and the engine still performs well. Compression 1 = 155, 2 = 154, 3 = 150 4 = 149, 5 = 149, 6 = 149 And when pulling the plugs ALL of bank 1's plugs (cyl 1-3) look identical to this. Whereas ALL of bank 2's plugs look identical to this. Pulled the headers and the exhaust side of bank 1's head is all black and sooty after only 500 miles already whereas bank 2's head is relatively clean (albeit not sparkling like it was after the valve job). So now I am a little stumped, perhaps it is due to a fuel delivery problem? I thought perhaps the MAF could cause this, but then I should see consistency between both banks. Found a great thread on the subject, however again the problem here is with 1 bank and not both. http://www.renntech.org/forums/topic...el-air-mixture Perhaps it could be O2 sensors, however they are all brand new (and same problem with the old ones). When I did the rebuild I had all the injectors sent off, tested, cleaned, and orings/filters replaced. I also cleaned the fuel rails as best I could with compressed air - there were no apparent blockages. I seem to remember that the design of the fuel rails might have changed with later model year cars. Perhaps this is just how the 1999 model M96-01 runs? A little richer on bank 1 than bank 2? Anyone else notice this? Pulled out the Durametric to log some data. Any more data you would like to see? At idle and up to about 3000 RPM FRA for bank 1 and 2 is 1.04. Above 4000 RPM FRA goes to .98 for both banks TRA for bank 1 is always -0.14 and for bank 2 -0.17 Hot film MAF 1.3 volts at 680 rpm idle, and 17kg air mass. On up to 500kg at 6000 RPM and 3.41 volts. (MAF was cleaned w/CRC cleaner during rebuild). How do I explain this soot buildup in bank 1 but not bank 2 ???? It's driving me crazy !!!!!! Brand new AOS dumping oil into the intake on bank 1 ???? (third AOS on this car). I meticulously cleaned all of the AOS tubes and completely overhauled the SAI system to boot. Then again, perhaps I should just ignore the soot and keep driving it. At least I'm sure that would be the advice of some... but I can't seem to ignore it after sooooo much hard work. One of my favorite quotes from this great thread is from Macster: https://rennlist.com/forums/997-foru...l-or-fuel.html "For street cars as long as the engine's running ok, the CEL is not on, flashing, the engine exhibits no untoward behavior, oil consumption is within the allowed range, fuel consumption is in expected range, and coolant is not disappearing into the engine, the exhaust tips could be plaid for all that it matters." Bank 1 Tail Pipe (looks blacker in person, camera is brightening it up) Bank 2 Tail Pipe

It's obvisouly bank 1 is burning some contaniments to produce that extra sout. you had the heads off right? Is it possible the seal isn't good? After 500 miles, any change in your coolant level? (you already said the oil hasn't moved)

Hey Sean, I'm pretty confident the head gasket seal is good. I used acetone and lint free wipes to ensure no debris on any of the surfaces. I followed the factory specs for torque and ordered new head bolts that were lightly oiled before installation. No leaks externally around the head gasket. Also if there was a leak on the head gasket I think I would see that show up somewhere on the leakdown test. No change in coolant level and no sign of oil in the coolant. Thanks. p.s. any news on your car? Did you get it back yet? edit: oh forgot to mention this problem started about 1.5 years ago before the top end repairs (well after your cats were pulled as they had been sitting in storage for years BTW ).

So, logray, have you seen those autofarm 3.7l cylinders I think that you are just trying to convince your self that the car need's new block Just kidding, my car runs a bit too rich on both banks.

Hah you know me too well speed rII. While that is in this engines future, I don't think just yet... I would like to get to the source of this soot though. Seems odd according to leakdown test if cylinder and/or piston/ring wear is similar on bank 2 why am I not seeing soot from that tailpipe too? Almost makes me think if I went ahead and put in new rings and sleeves I would still see the soot. Someone on RT mentioned fuel vacuum or return line but not sure where they're going with that yet.

.........news flash......... Could this soot be related to timing and/or a faulty variocam actuator? Reason being, shortly after I reinstalled the eninge, I had a P1531. The solenoid/actuator failed to activate using Durametric. The solenoid read near 0 ohms with the multi meter. So I dropped the engine again and replaced the solenoid with a used unit. After 500 miles hooked up the Durametric and P1531 was stored, but hasn't set the CEL yet. Cleared it, took it for a drive, P1531 set again. Sh**. Pardon me. This is getting silly. So, out comes the mutli meter again. The "used" solenoid I put in ohms out fine now. Swapped cam positions sensors between banks. (PITA) P1531 (174) code still sets after it's cleared. What's strange though is now I can activate both banks and the idle changes noticeably. Too bad I don't have a newer Motronic, I could monitor actual angles as well. Checked the wiring and it is good (in fact I even did some repairs to it after second the engine drop, noticed one of the wires was kinked so I spliced and re-soldered VERY carefully (I do a lot of soldering). So I am thinking the actuator is faulty at this point??? Perhaps it has been marginal for a long time and is either sticking either open or closed and hasn't been actuating as it should. Maybe this causes a difference in timing, perhaps leading to slightly different valve opening/closing resulting in less than 100% fuel burn off leading to soot in all of bank 1? Grasping with that theory I suppose. Or perhaps the used solenoid I installed was also bad or on it's way out. On a 3.4L does anyone know if the DME is smart enough to disable variocam actuation on both banks if it sees a cam activation issue.. to support my theory above ? BACK into the engine again after I source some more PARTS. Yay.

how much are new actuators? I'd replace both and put that headache behind you....You'd change them out and wouldn't have to worry/think about the actuators at all. my car is back...and is going back to them this Sat :| He thought he fixed the issue by replacing two fuel injectors, but when I got in the car...the issue was still there.

Brand new actuator plus the solenoid new sets me back just shy of a grand or so.

Hey thanks for he pictorial write up. I have a 98 Carrera 2 that looks like its got a cracked head and this will certainly help me. I noticed on your album that you had your engine on a pallet all shrink wrapped as of 20 Mar 2012? How come its out and wrapped? Thanks Steve

Hah, old thread from long long ago. Have you seen this thread? https://rennlist.com/forums/996-foru...-part-2-a.html Or this one? https://rennlist.com/forums/996-foru...he-finale.html Anyways, that's actually not my engine, I am helping out a friend with his car, I've actually taken those pics offline for the time being. My car is in my garage being driven daily.

>>> a harmonic under drive pulley Who makes a harmonic & underdrive pulley? I'l be wanting one that was both.

LOL... been lurking here and there but haven't had much time for the forums at all... sorry. Anyways, did you see the post I made above yours? ???? Also: not sure if F6I is still selling pulley's separately but here's a link for you: http://www.flat6innovations.com/shop...cat=309&page=1 BTW: rebuilt engine has about 5,000 miles on it (and 5 autocross events), and it is still performing awesome, I swear it has more power and is running better than when I had it dynoed... this winter if I can raise some money for tires and dyno time I might get it on the rack again. Cheers...

Quotes source post: 9895553

Logan, Lurker as well. Been wondering if everything was good with you. I learned so much from following your rebuild posts. Still would never even think about trying it myself but very happy to hear yours is running well!

o.

Great pictures, I am in awe!

A massive help as always. A real nice load of photos.

wow great pix. Thanks!

Old Thread I know, but I am in the middle of doing this work myself and this thread has been very helpful. Thanks Logray! Great work.