Yet another 996 Cylinder 1 misfire thread
#256
Rennlist Member
Ok, now I feel horrible for the guy. He can't seem to catch a break. Count me in on the crowd sourcing for $100.
#257
Shouldn't it be part of your quality control process to verify that the parts you are using have not been superseded?
Seems to me that if Porsche felt the need to EOL a part and replace it with a different one that they had a good reason. If that is the case then using the old version seems like a bad idea.
Seems to me that if Porsche felt the need to EOL a part and replace it with a different one that they had a good reason. If that is the case then using the old version seems like a bad idea.
Martin said they were new - not the latest and greatest form porsche.
There's a difference.
#258
Race Director
Shouldn't it be part of your quality control process to verify that the parts you are using have not been superseded?
Seems to me that if Porsche felt the need to EOL a part and replace it with a different one that they had a good reason. If that is the case then using the old version seems like a bad idea.
Seems to me that if Porsche felt the need to EOL a part and replace it with a different one that they had a good reason. If that is the case then using the old version seems like a bad idea.
#259
I get several NOS items from Europe all the time for my BMW's. Doesn't mean it's inferior in any way or has been used.
#260
https://rennlist.com/forums/996-foru...30k-miles.html
#261
As you point out, these are still new (and I'm not questioning that) which is different than reusing the old ones.
I think a key difference, however, is that doing it DIY you are the only one to blame and feel the pain if the choice ultimately turns out to have been a bad one.
I know nothing about lifters so I'm not even trying to really judge that the newer part is indeed better. Just from a business quality perspective it seems to me that if you are using factory parts, then using the latest revision available is the most logical path.
The opposite is also true though where 996s have some 993 parts and 997s have some 996 parts. In those cases the parts were obviously fine and needed no revision so they just kept with it.
For something like the cabin filter, yeah who cares if you slap a 996 version in rather than the newer 997 version we are supposed to use. The chances of something adverse happening there is pretty slim. Are engine internals as easy to write of the changes (I have no idea what makes the difference between the lifters, maybe it really is nothing important)?
I spent a few years selling military aircraft parts and they get touchy about getting superseded parts (well the US government rarely checked, but the Japanese were super **** with their receiving QA!). Maybe that time has jaded me, but if I pay for critical new parts and find out later they weren't the updated versions I'd be pretty pissed about it.
I think a key difference, however, is that doing it DIY you are the only one to blame and feel the pain if the choice ultimately turns out to have been a bad one.
I know nothing about lifters so I'm not even trying to really judge that the newer part is indeed better. Just from a business quality perspective it seems to me that if you are using factory parts, then using the latest revision available is the most logical path.
For something like the cabin filter, yeah who cares if you slap a 996 version in rather than the newer 997 version we are supposed to use. The chances of something adverse happening there is pretty slim. Are engine internals as easy to write of the changes (I have no idea what makes the difference between the lifters, maybe it really is nothing important)?
I spent a few years selling military aircraft parts and they get touchy about getting superseded parts (well the US government rarely checked, but the Japanese were super **** with their receiving QA!). Maybe that time has jaded me, but if I pay for critical new parts and find out later they weren't the updated versions I'd be pretty pissed about it.
#264
Rennlist Member
It seems like he may have burnt bridges from two top guys here now. First he said LN retrofit caused his engine to fail IIRC, and now this. If he really did encounter bad luck two times in a row, he shouldn't bother crossing the street if I were him. It also begs the question if he's using the same shop in this situation that he used the last time.
https://rennlist.com/forums/996-foru...30k-miles.html
https://rennlist.com/forums/996-foru...30k-miles.html
FYI, I do know someone that had metal flakes at an oil change on the magnetic drain plug. The shop immediately replaced his failing IMS with a retrofit and the car has run fine ever since. I think this simple act would have saved the cost of two engines.
I also think that sending his engine to someone that had a vested interested in diagnosing it as "bad" was a poor choice. I'm not saying MBM lied, I just wouldn't want to put them in a position to benefit by doing so. I didn't read anything that said that the engine was running poorly, only that the metal continued to flake as DrMems continued to drive it. He said two mechanics said to continue to drive it but I'm willing to bet Jake wasn't one of them.
#265
Instructor
Thread Starter
I talked to Jake about FRAU and RKAT and he said that my numbers were just right. They also showed no vacuum leaks.
#266
My engine mounts were worn: The bolt on the bottom of each old mount stuck out about half an inch farther than on the new mount. Replacing them did not help the vibration in the car when idling.
I talked to Jake about FRAU and RKAT and he said that my numbers were just right. They also showed no vacuum leaks.
I talked to Jake about FRAU and RKAT and he said that my numbers were just right. They also showed no vacuum leaks.
Still more misfires on cyl #1?
#267
Instructor
Thread Starter
I'm near San Jose, California and Jake is in Georgia and I missed him when he came out here for a class, so he has not looked at it.
This weekend I'll put a new coolant temperature sensor in to see if that helps anything. (It's part number 996.606.410.00-M100. Pelican Parts' website says that this part number is a coolant sensor, but Pelican's sticker on the part says it's an oil-temperature sensor. I though that the oil-level sensor and oil-temperature sensor were in the same module.)
#268
Not being able to hold it at 2000 rpm is normal. Try keep the clutch depressed next time (timing retard will aply) and you should be able to hold it at any rpm.
That p/n is correct for the coolant temp sensor. They must have put a wrong sticker. You're right that the oil level and oil temp are combined into a single sensor and it's like a foot long. If your durametric coolant temp reading is what you expect it to be, your coolant temp sensor should be fine.
The DME misfire detection should be pretty accurate and sensitive so is it possible what you're feeling/hearing are not misfires?
That p/n is correct for the coolant temp sensor. They must have put a wrong sticker. You're right that the oil level and oil temp are combined into a single sensor and it's like a foot long. If your durametric coolant temp reading is what you expect it to be, your coolant temp sensor should be fine.
The DME misfire detection should be pretty accurate and sensitive so is it possible what you're feeling/hearing are not misfires?
#269
Instructor
Thread Starter
The engine was running roughly at idle (700 rpm). When stationary and revving it up to 1000, then 1500, then 2000 rpm, the roughness gradually decreased until I couldn't feel it by 2000 rpm. When driving, it seemed perfectly fine.
A few days ago I replaced the regeneration valve (P/N 996.110.129.53) because other drivers at Pelican's website had the same symptoms and this was the solution. I think that the valve was getting stuck open, effectively producing a small vacuum leak into the intake manifold. This is extra air that has not passed past the MAF sensor, causing the engine to run a little lean.
After several drives, with a warm engine, the rough idle has definitely decreased. There is still a little vibration when idling, but maybe I'm being too sensitive.
My finger is pointing to the regeneration valve
A few days ago I replaced the regeneration valve (P/N 996.110.129.53) because other drivers at Pelican's website had the same symptoms and this was the solution. I think that the valve was getting stuck open, effectively producing a small vacuum leak into the intake manifold. This is extra air that has not passed past the MAF sensor, causing the engine to run a little lean.
After several drives, with a warm engine, the rough idle has definitely decreased. There is still a little vibration when idling, but maybe I'm being too sensitive.
My finger is pointing to the regeneration valve
#270
Rennlist Member
That is great news! That will be huge if that was all it was. Keep us updated.