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Hey everyone, long story short, It's looking like I have significant scoring in cylinder 4 and minor in other cylinders and am struggling to keep compression. The car has been maintained pretty much to service spec with Fabspeed Race Headers and COBB being installed 1 month and ~1,500 miles ago. (service history attached). *NOTE, I am not blaming Fabspeed or COBB for the engine failure*
I'm completely open to advice and suggestions because this is not an expense I planned for / am easily able to afford. This is a decent bit out of my depth of knowledge. Sad story, but stay tuned for the build/swap because I am out of warranty.
So far I've been looking at engine replacement options and am just now looking into bore/building options.
I've spoken with John at BGB about an engine swap.
I've spoken with Jake Raby at flat6innovations about engine repair.
I have not yet spoken with PCNA if they're willing to offer any goodwill as I am just 1 year out of warranty while still under the initial 50k miles.
New engine with 1 year warranty.
3.4L Cayman S or GTS engine (MA1.23) $16.1k + core + tax + install
3.4L 911 engine (MA1.04) $15.7k + core + tax + install
3.8L 911 S engine (MA1.03) $18.5k + core + tax + install Used (runs risk of having bad repairs on the used engine), no warranty.
3.4L Cayman S engine with 11.5k miles (MA1.23) $9.75k, no core, no tax + install
3.8L 911 S engine with 30k miles (MA1.03) $12-13k, no core, no tax + install Build engine with 1 year warranty.
Built current engine ~$20k
Current engine bored to 3.8L ~$25k
Do you have the service records prior to your ownership of the car ? If you did have the records was the car properly maintained prior to your ownership ?
prior to purchasing the car did you have a PPI performed ?
Was the car over revved at any point ?
Where there any signs such as burning oil, excessive engine noise prior to the failure ?
You changed the oil and filter only once in 12000 miles? Just curious!
Spec is every 10k, so yeah, I ran a bit late on the recent one.
Originally Posted by Jim137a
Sorry to hear about your situation.
Do you have the service records prior to your ownership of the car ? If you did have the records was the car properly maintained prior to your ownership ?
prior to purchasing the car did you have a PPI performed ?
Where there any signs such as burning oil, excessive engine noise prior to the failure ?
I can call the dealer to get the past records again, but it was maintained correctly.
It's PDK, so no real over-revs. Last time I looked at the durametric it had a handful of revolutions in the 2nd over-rev category (out of 6).
There were no signs, just sudden loss of a cylinder, I pulled over asap and the car billowed white smoke. Cylinder 4 and the exhaust were flooded with fuel per the indy shop it's currently at.
I'm sorry to hear this. Hope Porsche will offer you some goodwill.
The several coil changes done over the past few years looked unusual to me. Especially for cylinder 3 at 35,100 and again at 39,502. What was the problem?
Sorry to hear this, best wishes. If it was me, I would do the low-ish mile used motor. There is some risk, but it is so much cheaper I'd take that risk. I've seen used ones for $8k or $9k.
On the causality, though, something seems weird. Cylinder scoring usually appears first as excessive oil consumption and smoking before anything catastrophic like what apparently happened to you. Did you notice anything like that?
1) There are parts that have to be exchanged from the 981 engine to a replacement 991 engine (new or used). Particularly the wiring harness and the oil manifold. John @ BGB did this as part of my 3.8L X51 upgrade in 2015.
2) Did the car get driven in cold weather? Many people here will disagree, but low mileage 9A1 engines have been reported by people I trust to score the cylinder walls if the car is driven vigorously (> 4000 RPM) in below freezing weather before normal oil temperature is reached (> 160F). Supposedly the piston to wall clearance is very tight until the engine gets to about 25K miles. After 25K miles, supposedly clearance opens up enough that cold temps don't score the cylinders, although it remains a good practice to let oil warm before going over 4000 RPM regardless of mileage.
3) Another possible cause is that a piston ring land/groove crumbled and scored the cylinder. A video borescope inspection might be able to see this if it was the top ring groove that crumbled. The top groove takes a beating due to DFI and high compression. Aftermarket pistons need the top ring groove (or all of them) hard anodized for life.
4) I assume you have pulled the oil filter and looked for metal particles in the pleats. The question is did other parts get damaged by debris (rod and crank bearings, etc). If there is no damage, there is a chance of a rebuild and getting LN Engineering to re-line the bore or bores.
1) There are parts that have to be exchanged from the 981 engine to a replacement 991 engine (new or used). Particularly the wiring harness and the oil manifold. John @ BGB did this as part of my 3.8L X51 upgrade in 2015.
2) Did the car get driven in cold weather? Many people here will disagree, but low mileage 9A1 engines have been reported by people I trust to score the cylinder walls if the car is driven vigorously (> 4000 RPM) in below freezing weather before normal oil temperature is reached (> 160F). Supposedly the piston to wall clearance is very tight until the engine gets to about 25K miles. After 25K miles, supposedly clearance opens up enough that cold temps don't score the cylinders, although it remains a good practice to let oil warm before going over 4000 RPM regardless of mileage.
3) Another possible cause is that a piston ring land/groove crumbled and scored the cylinder. A video borescope inspection might be able to see this if it was the top ring groove that crumbled. The top groove takes a beating due to DFI and high compression. Aftermarket pistons need the top ring groove (or all of them) hard anodized for life.
4) I assume you have pulled the oil filter and looked for metal particles in the pleats. The question is did other parts get damaged by debris (rod and crank bearings, etc). If there is no damage, there is a chance of a rebuild and getting LN Engineering to re-line the bore or bores.
V6
Stock piston to cylinder clearance is a whopping .0008", so cold starts or being hard on a cold engine is horrible, but with scoring on Lokasil and Alusil bores, the piston skirt coating wearing through or flaking off is typically the reason a bore scores, unless something like an injector fails. We had a new crate engine from Porsche fail after about 10 hours total track use with a scored bore, so it happens, event when broken in properly and run on the right oils. The only other thing I've seen take the bores out is if it got really hot (as in the plastic flow restrictors melted into the deck of the block).
Could still be a bad injector, excessive fuel dilution, or a combination of both with cold weather operation.
Any used oil analysis done on the engine pre or post diagnosis?
1) There are parts that have to be exchanged from the 981 engine to a replacement 991 engine (new or used). Particularly the wiring harness and the oil manifold. John @ BGB did this as part of my 3.8L X51 upgrade in 2015.
2) Did the car get driven in cold weather? Many people here will disagree, but low mileage 9A1 engines have been reported by people I trust to score the cylinder walls if the car is driven vigorously (> 4000 RPM) in below freezing weather before normal oil temperature is reached (> 160F). Supposedly the piston to wall clearance is very tight until the engine gets to about 25K miles. After 25K miles, supposedly clearance opens up enough that cold temps don't score the cylinders, although it remains a good practice to let oil warm before going over 4000 RPM regardless of mileage.
3) Another possible cause is that a piston ring land/groove crumbled and scored the cylinder. A video borescope inspection might be able to see this if it was the top ring groove that crumbled. The top groove takes a beating due to DFI and high compression. Aftermarket pistons need the top ring groove (or all of them) hard anodized for life.
4) I assume you have pulled the oil filter and looked for metal particles in the pleats. The question is did other parts get damaged by debris (rod and crank bearings, etc). If there is no damage, there is a chance of a rebuild and getting LN Engineering to re-line the bore or bores.
V6
1) how's the 3.8 X51 holding up after 3 years?
2) previous owner was in GA, I had the car in Florida, never driven hard cold by me.
3) borescope inspection is what was done to identify the scoring, not sure if the rings have been checked yet but that's what I suspect is the issue.
4) I haven't done this yet, happened Friday :/ I had not heard of LN Engineering yet, thanks!
Originally Posted by Charles Navarro
Stock piston to cylinder clearance is a whopping .0008", so cold starts or being hard on a cold engine is horrible, but with scoring on Lokasil and Alusil bores, the piston skirt coating wearing through or flaking off is typically the reason a bore scores, unless something like an injector fails. We had a new crate engine from Porsche fail after about 10 hours total track use with a scored bore, so it happens, event when broken in properly and run on the right oils. The only other thing I've seen take the bores out is if it got really hot (as in the plastic flow restrictors melted into the deck of the block).
Could still be a bad injector, excessive fuel dilution, or a combination of both with cold weather operation.
Any used oil analysis done on the engine pre or post diagnosis?
Injector likely started this, seems there was unburnt fuel in the cylinder and exhaust tubing. Haven't had any oil analysis done yet.
1) how's the 3.8 X51 holding up after 3 years?
2) previous owner was in GA, I had the car in Florida, never driven hard cold by me.
3) borescope inspection is what was done to identify the scoring, not sure if the rings have been checked yet but that's what I suspect is the issue.
4) I haven't done this yet, happened Friday :/ I had not heard of LN Engineering yet, thanks!
Injector likely started this, seems there was unburnt fuel in the cylinder and exhaust tubing. Haven't had any oil analysis done yet.
We (LN Engineering is my company) just finished repairing and upgrading a 3.4 9A1 block on the RND Engines side of the house. That might be another option you haven't considered. Flat 6 could do the install since you are so close to them. Just wanted to throw that option out.
Scored bores don't scare me on a core engine - we can easily fix that. Then at least you will have Nikasil bores and won't have to worry about scoring again.
We (LN Engineering is my company) just finished repairing and upgrading a 3.4 9A1 block on the RND Engines side of the house. That might be another option you haven't considered. Flat 6 could do the install since you are so close to them. Just wanted to throw that option out.
Scored bores don't scare me on a core engine - we can easily fix that. Then at least you will have Nikasil bores and won't have to worry about scoring again.
Oh, I hadn't even looked at your signature *facepalm*.
Can you shoot me a PM with details on that / other options or solutions?
08-16-2018, 12:15 PM
981 S Engine Failure at 43k miles
but if it was me I would go new 3.8 BGB install. Of course it helps that I am only 90 miles from John. 