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Discussion summary
YOUR RESEARCH996.1 C2 crankshaft failure
Leading reported evidence
Clean my mechanic told me
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
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0
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1
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Performed · outcome unconfirmed · Original poster
The engine was pulled apart and cleaned - my mechanic told me that the rest of the engine was in a reasonably good shape.
Leading evidence: 'Clean my mechanic told me' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Clean " mean' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
I had a repaired crank in our first test engine and it became a 3 pc crank after about 50 hours run time.
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Performed · outcome unconfirmed
Used cranks can be found, you just have to be patient.
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Performed · outcome unconfirmed
The problem will be the difficulty in locating a good used crankshaft.
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Suggestion
I've seen too many cracked original crankshafts to recommend welding any stock crank or trying to cut the cranks to use the available repair bearings offered.
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Suggestion
I've seen too many cracked original crankshafts to recommend welding any stock crank or trying to cut the cranks to use the available repair bearings offered.
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Suggestion · Original poster
My mechanic suggested to try and find a used engine from which we can pull out its crankshaft, change all the bearings (and maybe connecting rods?) OR to attempt to repair my current crankshaft (I have no idea how this would work).
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Suggestion · Original poster
And yes you are right, I am already a grand into this at least - I was intending to simply try and find a crankshaft and replace a few key parts of the engine to get it running again but after reading the comments in this thread I am more inclined to go for a full-on rebuild.
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Rennlist: 1 discussions
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Hey all, first thread here, too bad it isn't under different circumstances.
To make a short story even shorter, heard a small rattle that got progressively louder the longer I drove the car. Fast forward the next day to my indy mechanic, he tells me they need to pull the engine out - I was suspecting some form of bore scoring which lead to piston slap and as usual with those armchair diagnoses I was off. Engine is now out of the car and the damage has been identified as worn crankshaft originating from cylinder #5. The journal was in rough shape and I could feel an indentation with my finger. Rod bearings on some other cylinders were also somewhat worn out.
My mechanic suggested to try and find a used engine from which we can pull out its crankshaft, change all the bearings (and maybe connecting rods?) OR to attempt to repair my current crankshaft (I have no idea how this would work). We also discussed about potentially doing other reliability work while we are at it. The main issue is that both him and I struggle finding a used crankshaft that is in good condition, he pulled out an m96 engine from a boxster with 90k KM and he told me the crankshaft was no good. What do you guys think of my situation? Would it also be worth it to look at a new crankshaft?
Thank you all!
The problem will be the difficulty in locating a good used crankshaft. The second problem will be the crankshaft bearings and alignment. Might suggest a new Porsche short block that you can now get from a Porsche dealer for around $6500. That will have everything you need and comes factory fresh. Have the heads reworked and you will be good to go.
Rewelding and machining a crankshaft is a solution, but it takes skills and about $2K, then you have to get the engine all back together with new bearings and labor so ... IF you can get a short block from Porsche for $6500, I suggest you do that because the other route will get you to $5K anyway. Put the heads back on, ignore the valve job, drive. You'll be done for $10K.
With a failed rod bearing, there will be particulates throughout the engine. The heads will need to be completely dismantled and cleaned. the cams will need to be inspected to determine if there is any damage. Given the amount of effort that will take, you should send them off to have them rebuilt. No point in taking the risk of ruining the new short block.
Reworking the crankshaft isn't a viable option. We tried that years ago and they aren't quality. The repairs don't hold up. I had a repaired crank in our first test engine and it became a 3 pc crank after about 50 hours run time. Don't waste your time or money on trying to make what you have work.
Used cranks can be found, you just have to be patient. We normally stock them magnufluxed and polished for $2-3k.
78 strokes are easier to find as that crank is used in the 2.7, 3.2, and early 3.4s. 3.6 cranks are harder to come by.
3.4 cayman cranks are impossible to find - most customers end up swapping in an earlier crank carrier and smaller main journal diameter 78 crank from earlier engines.
Yes, you're right - finding a good crankshaft can be a waiting game. Thankfully I don't use the car during the winter and I can let it sit for a while. The short block from Porsche includes a crankshaft? Can you order it from suncoast?
To be honest I was hoping to be done for half that!! In all honesty the car is really good and I intend to fix it best I can in order to enjoy it for a few more years.
The engine was pulled apart and cleaned - my mechanic told me that the rest of the engine was in a reasonably good shape. I have not inspected the camshaft with him but I will certainly ask him and see if there is any issue on that side. How much would a rebuild cost? I'm looking to get the best reliability out of this unfortunate situation
Hey Pete, what engine was the crank pulled from? Can you give me some more info on mileage and condition? Thanks!
Truth be told I would also like to avoid reworking the crank, my mechanic tells me he does this all the time for racing application but I am still not entirely convinced. I looked on your website but I cannot find the crank for a 3.4, will you be having them in stock in the future? Thanks!
Hey Mark, I bought the car used and it had 90k miles. Did a pretty big service (oil+spark plugs, filters, complete brake job) and I drove it less than 500 miles before this issue occurred.
My mechanic speculates it is either a factory part that was not built up to tolerance or someone had redlined the car multiple times while cold... Very unlucky whatever the root cause was. I truly like this car so much (exclusive manufaktur build) that I am dedicated to save it!
You need to search this 996 forum and read threads about DYI engine rebuilds and owners who have had their engine professionally rebuilt. This will help you understand the items that need to be addressed and the complexity associated with a full rebuild. There are specialty tools and knowledge needed. There is no inexpensive way out. The least expensive solution would be to find a good used motor and install it yourself. You can probably do that for less than 10k, but there is a risk that the used engine could fail in the near future. It's a crap shoot. There are always additional parts you have to buy when you do a big project like this, and it adds up.
Based on your description of the failure, it sounds like a rod bearing disintegrated. Rod bearing failures are often caused by low oil pressure, which can have several causes. A rod bearing failure is not instantaneous, and the failure could have initiated prior to your purchase when the bearing initially wiped on the crankshaft rod journal. Whoever sold it to you probably knew there was a problem.
As far as getting the heads rebuilt, Hoffman Automotive in Athens GA has been frequently recommend. The cost of rebuilding the heads will vary based on their condition, but a ballpark number would be around $2500.
Lastly, you may want to ask some probing questions to your mechanic. What does "disassembled and cleaned" mean? If the engine was truly disassembled and cleaned, you are probably into the rebuild over $1000 in labor at this point. Also, parts being in "reasonably good condition" to me means that only half of them are going to go in the trash. An engine with 90k miles will need a lot of new parts, including parts that weren't directly affected by the failure.
If you love the car and have the funds, ship it to Jake and his team at Flat 6 Innovations in Georgia. If you are going to have your mechanic do a rebuild, he probably (definately) doesn't have the same level of knowledge. He probably can't do it much cheaper either, without cutting corners. In addition, the Flat 6 folks incorporate multiple upgrades that you won't have if you start with the Porsche short block.
Spot on. This isn't a small block Chevy. Everything must be quantified. I almost guarantee that the bores will be out of spec and the block will need to be redone, and that's just one of many things.
The cost on the heads above is spot on - we're even a bit more if everything is done that needs to be addressed like new springs, guides, seats, pressure testing, etc.
The M96 engine can't be rebuilt cheap. Those who claim to do so don't own the proper measurement devices to qualify the components or are just ignorant.
If you can't afford to fix it right, a used engine is the best choice for sure.
Buyer beware.
Sounds like your failure was identical to mine. Here is my crank failure at 50K, much of it at the track due to oil starvation on high G long sweeping turns (shown this before).
. I suspect that your car was tracked quite a bit so I would not try to save the engine. Sure there is a bunch of things wrong with it now. I would only rebuild with the experts like Jake. My learning was all my engines for the track will have deep sumps.
As painful as it may be, you came to the right place for the "truth" about your engine. Proper "rebuilds" are expensive. Improper rebuilds/refreshes are WAY more expensive and ultimately wasteful in the long run, as they will fail and trash the rest of the engine. Do yourself a big favor and read through the re-build threads on the site before you go further on your current course. It's not that it can't be done - it just needs to be done right or you'll be doing it all over again (or selling your car as a roller) if it's not done right. Good luck
The crankshaft I have came from a 1999 996 with 30k miles. It is still in the crankshaft �cage�. The engine had a top end failure (one of the heads was trashed). I just got it last week when I picked up some other non related parts.
You cannot do this for less than $5k. If it were my car, I would buy a $6K short block. Send out the heads for a $2K valve job. Reassemble with new gaskets and a few other things as needed to be replaced. Alone, the parts are running $10K. But this is the devil you know.
The other alternative is to buy a rebuilt engine at $9-$10K, and swap it. I would not buy a used engine from a junk yard. That is the devil you don't know.
Someone need to design/build and oil pressure warning light that is large and bright and is PRESSURE "AND" RPM sensitive.. The rule of thumb for high performance engine is 10 psi per 1k RPM......
lol..I'll think about it, If enough demand I'm sure I could make it happen. The hardest part would be write a sketch for an Arduino Controller to extrapolate Pressure signal to RPM signal,Then just tap on to the signal wires and hook to a Auto Meter Pro Lite or Pro Lite Mini or equivalent..
https://www.bing.com/aclick?ld=e3EzS...XVnMjlfMjAxOCk
Sorry to hear of the crank failure.
Most VW's had this until 2000-ish. My old VW's (1992 and 1993 models) all have a multistage RPM dependent oil pressure warning. 0.5 bar from idle to 1800-2000 RPM, 1.6 bar above that, with a LOUD buzzer and a flashing red light - in addition to an analog 0-10 bar gauge.
Of course that's to protect a lowly 12 valve VR6 engine which can be rebuilt for less than $1000 or found in any junkyard in the US for $500.
Huh, I guess that's why my '82 Sirocco flashed and buzzed at me at idle. I always thought it was an electrical issue because if you hit the dash hard enough, it would turn off lol. I knew deep down I had low oil pressure though..
OP sorry for the failure as well.
Thank you for taking the time to type this out, I will definitely be reading some of those rebuild threads. One issue is that while I currently live in the US the car is in still in Europe (since I was using it for my summer vacation). I was not present when the engine was torn apart but I was told the bearing was twisted out of its position but not broken, not sure if this is better or worse. And yes you are right, I am already a grand into this at least - I was intending to simply try and find a crankshaft and replace a few key parts of the engine to get it running again but after reading the comments in this thread I am more inclined to go for a full-on rebuild. Also, during the short time I drove the car, I had noticed that my oil pressure gauge was reading somewhat low when the car was warm (less than 1 bar on idle) but I did not pay too much attention since I've heard it is not exactly a super accurate reading. In any case, I wish Jake had an EU shop setup so that I could ship it to him!!
Thank you again for your insight, hopefully I can get this done right since the car deserves better than to be sold as a roller.
Wow this looks bad, my crankshaft looked fine on the surface - I could feel a small indentation on the fifth cylinder (nowhere near this level). Hope you got your car fixed!
I have driven 100k km's with welded and grind crank. Must be just lucky then. Or maybe my machinist was just better than the one Charles used?
Same journal 5. But, if you find a good used or have the funds to get new short block, I would go with one of those options.
I've seen too many cracked original crankshafts to recommend welding any stock crank or trying to cut the cranks to use the available repair bearings offered. Anything that further compromises an already crappy forging is too much of a risk considering the possible collateral damage from a crank failure.
