Scored cylinders!
07-29-2015, 12:30 PM
#122
Former Vendor
Anytime someone is concerned with extreme environments, or moving to a different climate, I will choose my happy median clearances.
This means that the engine will run well in extremes both ways. This is what the factory tries to do.
The benefit of a hand built, fully blueprinted engine is being able to set it up for application specific, or environment specific operation. It doesn't mean that we have to do this, and every owner can request median clearances, or specific clearances for an engine.
People don't sell cars after I build the engine. I know of two in the last decade that have been sold. It makes no sense to buy my engine, and then sell the vehicle.
This means that the engine will run well in extremes both ways. This is what the factory tries to do.
The benefit of a hand built, fully blueprinted engine is being able to set it up for application specific, or environment specific operation. It doesn't mean that we have to do this, and every owner can request median clearances, or specific clearances for an engine.
People don't sell cars after I build the engine. I know of two in the last decade that have been sold. It makes no sense to buy my engine, and then sell the vehicle.
07-29-2015, 01:22 PM
#123
Three Wheelin'
08-30-2015, 06:20 PM
#124
Track Day
Join Date: Apr 2015
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Jake, I was informed that the scoring issues are much more common with the 3.6 then the 3.4 ie 2002 and later. Would you consider this to be accurate information and also I was wondering if Jumpers noise in his video was in fact scored cylinder or was it something else..sorry I could not find the post with the resolution. Thanks
08-30-2015, 06:32 PM
#125
Former Vendor
Jake, I was informed that the scoring issues are much more common with the 3.6 then the 3.4 ie 2002 and later. Would you consider this to be accurate information and also I was wondering if Jumpers noise in his video was in fact scored cylinder or was it something else..sorry I could not find the post with the resolution. Thanks
08-31-2015, 04:32 PM
#128
Former Vendor
Its hard to score ANY Nikisil bore, including the 996/997TT and the GT3. The pistons used in these engines do not have an iron/ phosphate wear surface coating, like the M96/ M97 and Cayenne engines use. The failure of this coating is phase 1 of a 4 phase process leading to cylinder failures.
BUT the aforementioned cars are seldom operated in extreme cold, so the chances of issues are greatly diminished for that reason alone.
BUT the aforementioned cars are seldom operated in extreme cold, so the chances of issues are greatly diminished for that reason alone.
05-12-2022, 06:20 PM
#132
In my experience if this was a cylinder scoring issue it would have never lived through a dyno, and it would be consuming oil with that heavy of a knock. Could be wrong though. It also doesn't have the rhythm of a failing cylinder, which has a rhythm much different and sounds exactly like a lifter.
The noise could also be the crank dancing fore/aft because the end play shims have worn, failed and ended up in the sump. Grab the crank and shove it fore and after (engine off!) to see if it moves freely.
True, but you can see the scoring with a borescope introduced into the back side of the cylinder bore and accessed via removal of the sump plate. :-)
The noise could also be the crank dancing fore/aft because the end play shims have worn, failed and ended up in the sump. Grab the crank and shove it fore and after (engine off!) to see if it moves freely.
True, but you can see the scoring with a borescope introduced into the back side of the cylinder bore and accessed via removal of the sump plate. :-)
Questions:
- From where should I “grab the crank and shove it fore and after”?
- if that’s the cause. Can the shin be easily replaced?
For context:
I have a 14 Panamera Exec 4S with the 3.0L V6 and 2 turbos.
It is making a very loud “lifter metallic noise” that STOPS completely around 2700RPM. Not sure if this engine has Nikasil, but it is a cold climate NY car.
Last edited by echang033; 05-12-2022 at 06:21 PM.
05-12-2022, 07:03 PM
#133
Rennlist Member
@echang033 - I'm answering for you because Flat6 may not be returning to this board anytime soon. First off; it sounds like you are asking about a completely different engine than the M96 found in the 996 Porsche 911. My answers are regarding the M96 engine that Jake was talking about, so I cannot guarantee you that the components of your 3.0 V6 are even remotely similar. I would doubt they are.
1) You will not be able to grab the crank and move it fore/aft by hand with the engine assembled. Jake was describing a motion with the engine in operation and the forces enacted on the crankshaft were causing it to move on the worn shims.
2) The shims in the M96 are about as deep as deep can get inside of the engine and if I were going in to replace them I'd consider looking at a rebuild while I'm at it. They sit within the cranshaft cradle assembly and the case must absolutely be split in order to reach it.
Best of luck to you.
1) You will not be able to grab the crank and move it fore/aft by hand with the engine assembled. Jake was describing a motion with the engine in operation and the forces enacted on the crankshaft were causing it to move on the worn shims.
2) The shims in the M96 are about as deep as deep can get inside of the engine and if I were going in to replace them I'd consider looking at a rebuild while I'm at it. They sit within the cranshaft cradle assembly and the case must absolutely be split in order to reach it.
Best of luck to you.
