Bore scoring. I know it’s been covered already , but different question
10-26-2018, 02:32 AM
#1
Bore scoring. I know it’s been covered already , but different question
Hi all
I have what appears to be an almost symptomless case of bore scoring and wanted to sound it out here.
Car is 2004 S with 230000KM. I have had the vehicle for about 9 months without issues.
Recently I have developed the good old knocking sound ( not that loud and goes away with increased revs) I have checked the plugs ( none fouled) checked my coils ( none cracked but all are rev 03) I have virtually zero oil consumption and no excess smoke on acceleration or lift ( little hard to tell now as it is only around 3 deg C and damp now here in Finland)
I have no CEL, no misfires and other than the noise no symptoms.
Any ideas?
I have what appears to be an almost symptomless case of bore scoring and wanted to sound it out here.
Car is 2004 S with 230000KM. I have had the vehicle for about 9 months without issues.
Recently I have developed the good old knocking sound ( not that loud and goes away with increased revs) I have checked the plugs ( none fouled) checked my coils ( none cracked but all are rev 03) I have virtually zero oil consumption and no excess smoke on acceleration or lift ( little hard to tell now as it is only around 3 deg C and damp now here in Finland)
I have no CEL, no misfires and other than the noise no symptoms.
Any ideas?
10-26-2018, 12:41 PM
#2
Banned
Join Date: Mar 2011
Location: Spring Lake, NJ, US of A
Posts: 10,085
Received 1,140 Likes
on
758 Posts
It would seem like scoping the cylinders would be the next step in diagnosis to take.. but perhaps first trying to localize the knocking sound might be a productive step..
10-26-2018, 02:36 PM
#3
Burning Brakes
If you do have bore scoring, at 143k miles, that would be a new mileage record, I think. Mine, in my 2004 S, happened at ~45k miles. Deilenberger's survey 
, with 8 failures reported, has 2 between 90-120k miles, and none so far above 120k.
https://rennlist.com/forums/cayenne-...l#post15355875
Hopefully you're not setting a record on this one.
, with 8 failures reported, has 2 between 90-120k miles, and none so far above 120k.https://rennlist.com/forums/cayenne-...l#post15355875
Hopefully you're not setting a record on this one.
10-26-2018, 02:51 PM
#4
If you do have bore scoring, at 143k miles, that would be a new mileage record, I think. Mine, in my 2004 S, happened at ~45k miles. Deilenberger's survey , with 8 failures reported, has 2 between 90-120k miles, and none so far above 120k.
https://rennlist.com/forums/cayenne-...l#post15355875
Hopefully you're not setting a record on this one.
, with 8 failures reported, has 2 between 90-120k miles, and none so far above 120k.https://rennlist.com/forums/cayenne-...l#post15355875
Hopefully you're not setting a record on this one.
By paying very close attention today I noticed after a cold start I did get a small cloud on hard (ish) acceleration until engine oil was up to 90c. I pulled the AOS hose and it is quite oily. Now I just need to find an EU source for the diaphragm as a quick test. Seems some people have had bore scoring scares that have turned out to be a failed AOS diaphragm.
If if not and it does turn out to be scoring then it looks like I will be looking for a wrecked 9PA in the near future.
For clarification I have driven almost 8000km since the noise started and I guess the lump would have given in by now if it was scoring.
Will monitor and come back with any updates.
10-26-2018, 08:51 PM
#6
Nordschleife Master
I highly doubt a scored motor would last 8k kms (5k miles).
Its a progressive condition, and it usually progresses fairly quickly.
12-14-2018, 12:43 PM
#7
Trending Topics
12-14-2018, 06:33 PM
#10
RL Community Team
Rennlist Member
Rennlist Member
12-14-2018, 06:43 PM
#11
Rennlist Member
Haven’t used them myself yet -> https://vanos-bmw.com/membrane-94810...enne-45l-450ps
12-14-2018, 07:39 PM
#12
Advanced
Join Date: Apr 2018
Location: UK
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
Now the clatter is much reduced when cold and totally gone when hot. I actually struggle to tell if their is any difference with an ear pressed on the bonnet above each bank. Don't get any P0011 DTC's any more either.
I've been driving it this way for the last 2,500 miles, suppose it could still be bore scoring ?!
12-14-2018, 07:51 PM
#13
Grab a 9v pp3 battery and make up some leads. Take the connector off the vvti solenoid and use the leads and battery to cycle them. So hold -ve on one spade connector and tap away at the other, then reverse. Should get a thuck sound if they’re free. I did mine every few months like this on my 05 as they were a bit sticky and made the car sound like a diesel. After regular flushes, oil changes and cycling they came unstuck and never happened again. I then did it as preventative maintenance.
12-14-2018, 11:01 PM
#14
An old trick to unstick lifters is to add a quart of atf to the oil and run it for a hundred miles and then change the oil and filter.
‘Please don’t assume that because a noise comes from a Porsche engine then it has to be piston slap and it just can’t be anything else. Some posters just love to spread hear say and have no actual experience in anything except reading forums and jumping on bandwagons before they know any facts.
‘Good luck with finding the truth.
12-15-2018, 01:14 AM
#15
Banned
Join Date: Mar 2011
Location: Spring Lake, NJ, US of A
Posts: 10,085
Received 1,140 Likes
on
758 Posts
Whitegalaxie - thanks for your thoughts. Indeed any engine can suffer a failure of any kind, but the V8 Cayenne 4.5L and 4.8L engine failures are widely reported on this forum. I've been here for a while, and can't recall one incident of lifter failure (not to say it can't or never happened - but it certainly isn't common.) The vanos-control solenoid - as tats points out - has appeared in some small number of failures reported (typically with engines that got the oil changed on Porsche's schedule, on the 4.5L '06 engines that was a 20,000 mile interval.) Most of us change oil more frequently than Porsche calls for.
Unfortunately - aside from the 4.5L coolant pipes - the most common failure from 2003-2009 is bore scoring. That's not "hear say" - that's reported failures here, and in the bore-scoring survey that's referenced in the stickies. You might spend a bit of time looking at that survey.
Unfortunately - aside from the 4.5L coolant pipes - the most common failure from 2003-2009 is bore scoring. That's not "hear say" - that's reported failures here, and in the bore-scoring survey that's referenced in the stickies. You might spend a bit of time looking at that survey.