60 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHYes but, LN can resleeve it no?
Leading reported evidence
Run but knocked, and was a core
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Seller said it 'ran but knocked, and was a core for rebuild'.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
If sold as a core engine no fault to the seller you take your chances, I always assume that the pistons and cylinders are getting replaced on any rebuild and that block will most likely be salvageable.
Leading evidence: 'Run but knocked, and was a core' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'best offer i�m going' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Replace on any rebuild' (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.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Even had oil in it and coolant remnants from being ran on a dyno for $6800 and "no core charge" .
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I remember a time when Porsche ran a sale on 3.4 complete engines, from headers to throttle body, wiring everything !!!
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Good used 3.4 or 3.6 heads will bring 750-1000 USD each on the used parts market.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Replace on any rebuild
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
If sold as a core engine no fault to the seller you take your chances, I always assume that the pistons and cylinders are getting replaced on any rebuild and that block will most likely be salvageable.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Again, if scoring was so bad that it would cause this, the engine would literally have oil dripping out the exhaust and would be using 1 quart every 100 miles.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
60 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T091943Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
When I bought this engine, I was hoping to at least have a core to work with. Oddly, the head that I pulled off looks like it was not impacted and seems to be good. Maybe I can sell of some parts and ancillary items to recoup a few bucks.
Probably, they just look for holes on the outside of the case, not internal damage. AFAIK they don't "rebuild" the cores anyway, the "reman" long blocks are actually all new parts, just sold under the reman price structure. (for now)
Well, we haven't seen the bottom yet, but from what we can see, looks like the piston was scoring/gaulding/overheating trying to seize, but kept running on the other cylinders until it finally jerked the whole pin from the piston(splitting it in half).. Just a guess though..
BTW: I don't believe this will be a candidate for a LN Nickies sleeve, I'll bet the bottoms of the cylinders are broken out which will means no lower support for the sleeves, they machine out the complete upper part of the cylinder and into the case, but need the lower part for support...
I tried to buy a new shortblock from Porsche Kelowna a week ago, all went well until I told them my shortblock had a crack in the #3 cylinder- apparently that�s on the list of �not acceptable�
I bet the crank is buggard aswel from the impacting from the cylinder, what side is that , I've got a 4-6 case half that needs I sleeve out my old engine , it threw a rod and some debris went up the cylinder but it's not bad ?
If sold as a core engine no fault to the seller you take your chances, I always assume that the pistons and cylinders are getting replaced on any rebuild and that block will most likely be salvageable. So far you have usable heads, a block and hopefully a crank and carrier. In the end for the price of a factory short block you end up with a LN block with better pistons and rods and the option of going bigger.
That damage looks to have cracked the cylinder at the bottom so that case is scrap unfortunately, let me know if your interested in buying my 4-6 case , I've got a piston too it's not perfect but you could maybe build it up to get a qualification for a short block ??
Or use it if you go for a resleeve option?
I went through something very similar once with a Jaguar engine. Seller said it 'ran but knocked, and was a core for rebuild'. Of course, the engine was entirely scrap except for the head. Took him to small claims, wheeled the engine right into court on a dolly, had the judge look at it, and was awarded $2200 in about 10 minutes. Thankfully the seller had some other vintage cars, and a workshop with lots of tools so after 14 months I eventually collected. This is not a core, this was not running and knocking when removed.
I blew my 2000 3.4L on the track last year due to oil starvation...crank bearing failure and destroyed one cylinder like yours. If its a 3.4 maybe we can take two halves and make a whole if they are from different sides.
They may have tightened up on the requirements, never know until you ask. I remember a time when Porsche ran a sale on 3.4 complete engines, from headers to throttle body, wiring everything !!! Even had oil in it and coolant remnants from being ran on a dyno for $6800 and "no core charge" . Sale lasted about 6 months.
The requirement our dealer has stated is the engine must be running/rebuildable, even though we all know they probably get scrapped.
It use to be as long as the case was not windowed, but now with the shortblock program, they can clearly see a catastrophic cylinder failure and disqualify a core instantly.
We have processes to fix this, but on a early block like that, it's not worth the added expense when we can find core blocks without serious damage for $1-2k. 3.4 Cayman S or 3.8 997 blocks are a different story. Those are worth their weight in gold.
A cylinder failure below the bottom of the water jacket (crankcase side) is always related to a rod failure, either due to stretched rod bolt, oil starvation or aeration, and spun rod bearings that result in the rod coming apart. Less common, although also possible, is a rod beam failure, that takes out the cylinder.
I don't see scoring escalating to a cylinder cracking like the one in the photo.
I don't know man, that is some of the worst piston galling/seizing I have ever seen. I would tend to think if the rod broke first, the piston would stop moving and not have a chance to galled like that. I'm sticking to my piston seizing theory.
Charles: I was wondering about the picture in post #1 with the disintegrated piston and if it was possible that a root cause might begin with scoring? The pics in this thread are two separate engines.
Yeah that was my concern. I used to race two stroke karts and saw something similar on my 150cc open kart once. It leaned out, scored badly and yanked the piston off the pin. True it was a two stroke engine burning alcohol and two stroke oil turning somewhere north of 10k rpm, but...
I've seen much worse. The piston would have to wedge itself in the bore causing the rod to fail. It's certainly possible that debris took out the rod bearing and caused the rod then to fail. I can see that happening, but you would have horrible engine noise and oil consumption before it would let go like this.
Good Lord. I missed that photo. I've seen that carnage when an intake seat fails, slipped sleeve causes the piston to rip apart, or beam breaks on rod and rod pokes the piston to death.
Again, if scoring was so bad that it would cause this, the engine would literally have oil dripping out the exhaust and would be using 1 quart every 100 miles. Not to mention the noise.
Yes, I have seen serious seizing and pin jerked from the piston on a lot on 2 strokes, have seen it on Drag Nitrous motors also. This is the first m96 engine I have like that though. I have seen fresh engines go from fresh to scored, to galled, to seized, to pin jerked from the piston in a matter of seconds when conditions are right/wrong...When a piston starts scoring, if the load/temperature is not relieved, it will continue to tighten and increase temperature until the engine "stalls" or something breaks, usually the rod or pin boss. If when the scoring starts, the throttle/load is relieved and RPM lowered, the rapid increase will stop, and a slow increase of scoring and wear will start due to damage that has been done, but the piston will never get that tight/hot again due to increased clearance of the scoring.
Porsche says NO. They are a matched/machined set.
I have seen online E-bay sellers selling good halves, but I don't know how successful these repairs are.
I'm sure if enough care was taken to measure/machine/match all critical bores/dimensions it can be done, but would incur more cost, like Charles said in the broken lower cylinder case, it may not be worth it on these older cases. Charles?
Here's the dark side of the moon:
Bank 1
This is a good question. Assuming that it was the same model engine, I don't see why it shouldn't work. Mind you, I'm no expert, although I play one on YouTube.
You shouldn't mix case halves. If that was an option, Porsche would have sold them separately since first and foremost Porsche is in the business of making money. :-)
Yeah, that and the overall complexity of the design.
When the case is being machined, the halves are bolted together then the bore for IMS is machined. The result is a perfect hole with two halves. If you take a half from another set and mix it, the hole will not match perfect.
Same goes for the RMS FMS, is same process, half of each perfect bore is in each case half.
Also there is the machining of the inside of the case that centers the crank carrier and also provides a leak free oil seal to lube of the crankshaft/rods. Porsche even had problems with this centering early on resulting in the RMS leaks. The RMS was redesigned 5-6 times and a go-no-go special tool was designed to measure crank center of the case. If the go-no-go guage slipped in between the crank and the case, the crank was centered and a new designed seal could be installed. If the go-no-go gauge wouldn't go, the engine was replaced.
If a quality machine shop took the time to carefully re-machine all these areas, the cost would be more than what a used "set" of cases would cost..Then you still of course have to address the cylinder bores. Wouldn't it be cool if someone would designed and build some CNC Billet cases with drop-in replaceable Nickasil sleeves? Maybe someday, but probably not in my lifetime, I'll tell my children to lookout for it, they will inherit my 996's and 986..lol
Probably the best offer I�m going to see!
I�m going to take a good look at the heads and see if they are good. They do seem to have escaped the collateral damage at first glance. EBay is my friend here.
wonder if, were you to mix two case halves, you could line bore the ims shaft over a thou or so and install an oversize bearing to match? not sure about the other end? perhaps custom oversize bearingless shaft? eps sells a custom shaft (sorry jake) thats pricey, but if you get an inexpensive replacement case half and dont have to re- sleeve ...
Better to source a virgin, unmolested case. Too many variables.
Although Mythbusters proved you can polish a turd, it's still a turd. Sorry, I couldn't help myself. :-)
If the heads are untouched than that's worth some money. There is a demand for them so try to sell them but first have a really good look to make sure they are still OK. What did you pay for this engine?
The engine is a 2000 with 54K miles...was perfect except for the oil starvation issue on the crank bearing. Again, if you pay for shipping they are yours.
I also have the heads that seem perfect that I am willing to sell if someone is interested.
Good used 3.4 or 3.6 heads will bring 750-1000 USD each on the used parts market. May take a little while to sell, but someone will eventually need them. So you haven't lost any money on the purchase, and if you take the time to sell the other good parts, you will make a few bucks. What was wrong with your original engine? or was this just going to be a back-up motor?
This is a source reference. Confirm exact model applicability in the original material.
