Is it normal for the LEFT exhaust tips to be dirtier than the right?
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With a .1, if bore scoring occurs, it usually happens on the passenger side bank - cylinders 4, 5, and 6, but because the stock cats criss-cross each other, the soot shows up on the left exhaust tip. If you have an aftermarket exhaust with X cats, the side to side differences are less visible since the exhaust is more mixed and balanced.
With the .2 motor, scoring happens on the opposite bank, so the driver's side, but because the exhaust design is different and comes straight out without the criss-cross, soot on the left side is also the concern there, even though its coming from the opposite side of the motor than the .1 cars.
There have been a few reports of bore scored .2 motors, but not nearly as many as on the .1s. Monitor your oil consumption as that will be the first indicator. If consumption increases, you nay want to horoscope the cylinders, and its better to do it from the oil pan side of the motor rather than through the spark plug holes as it begins lower in the cylinder from the piston skirt, but once it becomes more prevalent, is then visible from the top as well.
With the .2 motor, scoring happens on the opposite bank, so the driver's side, but because the exhaust design is different and comes straight out without the criss-cross, soot on the left side is also the concern there, even though its coming from the opposite side of the motor than the .1 cars.
There have been a few reports of bore scored .2 motors, but not nearly as many as on the .1s. Monitor your oil consumption as that will be the first indicator. If consumption increases, you nay want to horoscope the cylinders, and its better to do it from the oil pan side of the motor rather than through the spark plug holes as it begins lower in the cylinder from the piston skirt, but once it becomes more prevalent, is then visible from the top as well.
Last edited by Gpjli; Mar 15, 2018 at 01:51 PM.
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Hello P. My concern here is that my motor and others on the forums ran this way from mile 1 (ie had no chance to develop scored bores). In addition it passed an alleged bore scoping by Porsche and yet still failed down the road. Overly rich condition on offending bank should be ruled out where you see this sort of thing. This was not done in my case until engine meltdown was under way. By the time you see the damage it can be too late.
Thinking further- wouldn't an "overly rich" condition show up in the diagnostics data being pulled? How would I convince Porsche that they have to evaluate each cylinder separately?
Last edited by Milt Ezzard; Mar 15, 2018 at 04:21 PM.
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But isn't there an inherent difference in how fuel is delivered to the cylinder in .1 vs .2 engines? i.e., DFI sprays fuel more directly at the top of the piston which provides some advantages in combustion (not pretending to know much on this subject, admittedly!)
Thinking further- wouldn't an "overly rich" condition show up in the diagnostics data being pulled? How would I convince Porsche that they have to evaluate each cylinder separately?
Thinking further- wouldn't an "overly rich" condition show up in the diagnostics data being pulled? How would I convince Porsche that they have to evaluate each cylinder separately?
Jake Raby shipped his setup to me in NY, I hooked it up, and he analysed how motor was running from his shop in Ga. I hate to say it but F...err...orget Porsche wrto these old motors. OP or others have the option of calling Jake or other 997 specialists when their tailpipes tell them something may be going on. Talking to the manufacturer about these issues is a waste of breath.
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A professional Durametric tool or the like allows the knowledgable (sp?)Tech to read what is going on inside a running engine and record parameters cyl by cyl, even shut individual cylinders down be or change settings on the fly.
Jake Raby shipped his setup to me in NY, I hooked it up, and he analysed how motor was running from his shop in Ga. I hate to say it but F...err...orget Porsche wrto these old motors. OP or others have the option of calling Jake or other 997 specialists when their tailpipes tell them something may be going on. Talking to the manufacturer about these issues is a waste of breath.
Jake Raby shipped his setup to me in NY, I hooked it up, and he analysed how motor was running from his shop in Ga. I hate to say it but F...err...orget Porsche wrto these old motors. OP or others have the option of calling Jake or other 997 specialists when their tailpipes tell them something may be going on. Talking to the manufacturer about these issues is a waste of breath.
Thank you!
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That's what has me scratching my head, too, Henry. It's either something is up with one of the cylinders in that left bank, or there's something wonky with the routing of the exhaust that causes the soot to settle more on the left side... but I think it's the former rather than the latter, or else EVERYONE with a 997.2 would see this too.
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Not true. I believe the sooty pipes are from burning oil. Some is normal. If it's more prevalent on one side, it means that one bank is burning more oil. Left pipe means right bank. Typically it's associated with a scored cylinder, but there could be other reasons.
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I see slightly more soot on my left pipe but only I would notice it. The car burns zero oil between oil changes and I don't suspect any bore scoring. I started noticing it after I installed my Fisters. Ive also observed more water coming out of my left pipe. Not sure why. What I suspect is the Fisters throw off a bit more soot and when combined with more water coming out of the left pipe, it can put a little stain the left tip.
Another issue that can lead to a sooty pipe is if you have a bad coil pack. I saw a 997 at my indy a couple months ago and the left pipe was jet black. You could see it from across the parking lot. I asked them what the issue was and they said a coil pack was bad causing the cylinder to run rich.
Another issue that can lead to a sooty pipe is if you have a bad coil pack. I saw a 997 at my indy a couple months ago and the left pipe was jet black. You could see it from across the parking lot. I asked them what the issue was and they said a coil pack was bad causing the cylinder to run rich.
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