Porsche Cayenne S piston / cylinder scoring issue statistics
09-24-2016, 02:46 PM
#16
I have been interested in buying a Cayenne S, so I recently looked at many posts on the piston/cylinder scoring problem.
It seems to me like this problem occurs most often in COLD climates where the vehicles are NOT DRIVEN HARD enough (or long enough) to get the oil up to the normal operating temperature.
Either the oil is too viscous to slosh up on the cylinder walls in sufficient amounts, or there is water that is frozen in/on the oil the pan/passages, or something like that.
Remember that the Cayenne S TURBO engines dont have this problem with piston/cylinder scoring. All the turbocharged engines have oil squirters built into the block that spray the backs of the pistons with oil. Normally aspirated engines dont have this nice feature. The oil squirters directly lubricate the cylinder walls. AND, the turbochargers themselves tend to heat up the engine oil more quickly, even when driven at minimal boost levels.
Also, remember that the Cayenne V8 is a DRY SUMP engine. There is some oil directly beneath the crankshaft, but not nearly as much as in a traditionally lubricated engine. There is just not as much oil being sloshed around in the crankcase. Also, dry sumped engines tend to have a large volume of oil in the entire system (just not in the crankcase). This large volume means that it takes longer for the oil to get to a temperature high enough to boil off any water mixed in with it. Water gets in the oil due to condensation as the engine goes through normal temperature fluctuations.
I ran across a few posts where people were angry that their engines had this failure even though they had "babied" their Cayennes since they were new. Well, maybe driving around in cold weather very slowly and carefully is the exact thing that initiates this problem. I wonder if Porsche sufficiently tested the Cayenne V8 in cold weather VERY GENTLY. Sometimes that which is best for an engine to run very hard for a long time doesn't work very well if the engine isn't run hard. Think about how Formula 1 engines overheat in just one minute if they are left to idle on the grid. The entire system is optimized for running at full power. I wonder if Porsche had placed any of the pilot Cayenne S vehicles with elderly couples in Finland. If they had, maybe they would have discovered this weakness in the design.
So, I based on what I saw in many posts and my own reasoning, I went and bought a 2006 Cayenne S the other day with 100,000 miles on it without much worry of having the cylinder scoring issue. I found one that had been in warm climates its entire life, and I plan to keep it in a warm climate.
However, if I must drive my Cayenne S when it is very cold outside, I will make sure that I flog it hard. I am picturing 4 wheel drifts in the snow just to get the oil up to temperature and get it sloshing up on the cylinder walls. I can easily explain the necessity of this aggressive driving to my wife using the logic above.
It seems to me like this problem occurs most often in COLD climates where the vehicles are NOT DRIVEN HARD enough (or long enough) to get the oil up to the normal operating temperature.
Either the oil is too viscous to slosh up on the cylinder walls in sufficient amounts, or there is water that is frozen in/on the oil the pan/passages, or something like that.
Remember that the Cayenne S TURBO engines dont have this problem with piston/cylinder scoring. All the turbocharged engines have oil squirters built into the block that spray the backs of the pistons with oil. Normally aspirated engines dont have this nice feature. The oil squirters directly lubricate the cylinder walls. AND, the turbochargers themselves tend to heat up the engine oil more quickly, even when driven at minimal boost levels.
Also, remember that the Cayenne V8 is a DRY SUMP engine. There is some oil directly beneath the crankshaft, but not nearly as much as in a traditionally lubricated engine. There is just not as much oil being sloshed around in the crankcase. Also, dry sumped engines tend to have a large volume of oil in the entire system (just not in the crankcase). This large volume means that it takes longer for the oil to get to a temperature high enough to boil off any water mixed in with it. Water gets in the oil due to condensation as the engine goes through normal temperature fluctuations.
I ran across a few posts where people were angry that their engines had this failure even though they had "babied" their Cayennes since they were new. Well, maybe driving around in cold weather very slowly and carefully is the exact thing that initiates this problem. I wonder if Porsche sufficiently tested the Cayenne V8 in cold weather VERY GENTLY. Sometimes that which is best for an engine to run very hard for a long time doesn't work very well if the engine isn't run hard. Think about how Formula 1 engines overheat in just one minute if they are left to idle on the grid. The entire system is optimized for running at full power. I wonder if Porsche had placed any of the pilot Cayenne S vehicles with elderly couples in Finland. If they had, maybe they would have discovered this weakness in the design.
So, I based on what I saw in many posts and my own reasoning, I went and bought a 2006 Cayenne S the other day with 100,000 miles on it without much worry of having the cylinder scoring issue. I found one that had been in warm climates its entire life, and I plan to keep it in a warm climate.
However, if I must drive my Cayenne S when it is very cold outside, I will make sure that I flog it hard. I am picturing 4 wheel drifts in the snow just to get the oil up to temperature and get it sloshing up on the cylinder walls. I can easily explain the necessity of this aggressive driving to my wife using the logic above.
I should also point out that I own a 2008 (so generation 2 957) Cayenne Turbo with the oil squirters etc you mention - car still had to get a replacement engine under CPO
From what the previous owner described this happened while towing a trailer in the middle of summer (so heat wasn't lacking)
09-24-2016, 02:56 PM
#17
Burning Brakes
^^^^This. Summarizing from Jake Raby's various posts, the scoring due to cold happens in the first few seconds after start-up, when the cylinder material doesn't expand as fast as the piston material. If Jake is correct, how the oil is brought up to temperature makes no difference because it's already too late at that point.
09-24-2016, 03:43 PM
#18
^^^^This. Summarizing from Jake Raby's various posts, the scoring due to cold happens in the first few seconds after start-up, when the cylinder material doesn't expand as fast as the piston material. If Jake is correct, how the oil is brought up to temperature makes no difference because it's already too late at that point.
My logic is that the heater will not only heat the oil but some heat will also find its way into the engine and safeguard against this phenomenon
09-24-2016, 04:06 PM
#19
Banned
Join Date: Mar 2011
Location: Spring Lake, NJ, US of A
Posts: 10,085
Received 1,150 Likes
on
763 Posts
You might be better served by putting in an in-line coolant heater (that goes into one of the multitude of hoses carrying coolant around the engine.) If you selected the right hose, it is likely possible to bypass the thermostat so you can get thermal/gravity circulation going (not possible with the oil due to the type of pump used) - which would warm both the cylinder walls and the heater core.
Win-win. No cylinder scoring and instant cabin heat when you start the engine.
Someone might figure out the correct hose to use - then make a special kit and sell it for an exorbitant amount of money and make a fortune. Gotta put that on my list of things to do..
09-24-2016, 05:12 PM
#20
The problem with an oil heater is the oil will remain in the sump and not circulate until the engine starts, and by then - it's too late.
You might be better served by putting in an in-line coolant heater (that goes into one of the multitude of hoses carrying coolant around the engine.) If you selected the right hose, it is likely possible to bypass the thermostat so you can get thermal/gravity circulation going (not possible with the oil due to the type of pump used) - which would warm both the cylinder walls and the heater core.
Win-win. No cylinder scoring and instant cabin heat when you start the engine.
Someone might figure out the correct hose to use - then make a special kit and sell it for an exorbitant amount of money and make a fortune. Gotta put that on my list of things to do..
You might be better served by putting in an in-line coolant heater (that goes into one of the multitude of hoses carrying coolant around the engine.) If you selected the right hose, it is likely possible to bypass the thermostat so you can get thermal/gravity circulation going (not possible with the oil due to the type of pump used) - which would warm both the cylinder walls and the heater core.
Win-win. No cylinder scoring and instant cabin heat when you start the engine.
Someone might figure out the correct hose to use - then make a special kit and sell it for an exorbitant amount of money and make a fortune. Gotta put that on my list of things to do..
Of course the best unit by far is the Webasto coolant heater (option from the factory and can be retrofitted)
09-24-2016, 05:20 PM
#21
The problem with an oil heater is the oil will remain in the sump and not circulate until the engine starts, and by then - it's too late.
You might be better served by putting in an in-line coolant heater (that goes into one of the multitude of hoses carrying coolant around the engine.) If you selected the right hose, it is likely possible to bypass the thermostat so you can get thermal/gravity circulation going (not possible with the oil due to the type of pump used) - which would warm both the cylinder walls and the heater core.
Win-win. No cylinder scoring and instant cabin heat when you start the engine.
Someone might figure out the correct hose to use - then make a special kit and sell it for an exorbitant amount of money and make a fortune. Gotta put that on my list of things to do.. :thumbsup:
You might be better served by putting in an in-line coolant heater (that goes into one of the multitude of hoses carrying coolant around the engine.) If you selected the right hose, it is likely possible to bypass the thermostat so you can get thermal/gravity circulation going (not possible with the oil due to the type of pump used) - which would warm both the cylinder walls and the heater core.
Win-win. No cylinder scoring and instant cabin heat when you start the engine.
Someone might figure out the correct hose to use - then make a special kit and sell it for an exorbitant amount of money and make a fortune. Gotta put that on my list of things to do.. :thumbsup:
09-24-2016, 06:01 PM
#22
Banned
Join Date: Mar 2011
Location: Spring Lake, NJ, US of A
Posts: 10,085
Received 1,150 Likes
on
763 Posts
Ive looked into this extensively - there are kits out there already - this one is for the european market (different voltage) but the premise is the same: clicky
There isn't a big reason for a pump in the heater. Thermo-circulation will work just fine. Hot water rises, cold water drops, circulation happens. The pump just adds something to go bad.
09-24-2016, 06:10 PM
#23
Banned
Join Date: Mar 2011
Location: Spring Lake, NJ, US of A
Posts: 10,085
Received 1,150 Likes
on
763 Posts
I disagree - the heater is on the lowest point on the engine and heat rises so it does lift the temperature of the entire block - I have verified this by measuring with an IR thermometer before and after
Of course the best unit by far is the Webasto coolant heater (option from the factory and can be retrofitted)
Of course the best unit by far is the Webasto coolant heater (option from the factory and can be retrofitted)
While *any* heat will eventually be transferred to other adjoining metallic surfaces, IMHO heating the coolant is the best answer since the coolant passages are placed in the castings at locations which effectively transfer heat from the bore of the engine to the coolant. The same will work in reverse.
The oil circuits in the engines are not closed systems like the coolant circuits, so thermo-circulation just isn't happening. Any heat transfer taking place is simply heat goes to cold (simple physics) and not very efficient since at the same time the heat will radiate from the engine block (which is what you're measuring with the IR thermometer.)
I believe the Webasto needs gasoline or diesel to run? That right away might be a problem if the vehicle is kept in a garage overnight. Combustion byproducts in an enclosed space can kill'ya..
Seems simpler and obviously much cheaper to install a resistance electrical heater that you just plug into the wall. I owned a Volvo DL5 that had a factory heater that took the place of a casting plug into the coolant passages in the block (casting plugs are frequently mis-named "freeze-out-plugs" - because that's what they do when the coolant freezes - but the holes are actually there to allow double-wall casting.) It had a 110V plug sticking out of the grille. I plugged a cord into it from my outside garage outlet and had a nice toasty car in the morning. That type of heater is still widely available - used often on large truck diesels so they don't have to be left running overnight - but you need to know where to install it on the engine and how to. Given the crappola (tech-term) that surrounds a modern auto engine - just seeing a casting plug might be considered a miracle, then you have to pull one out and see what fits.
Take a nice one of the Ebay ones that go into a hose, that costs around $120, do an installation video for it, toss in 2 hose clamps, put a fancy name on it (No-Bore V8)?(tm) and what's it worth to the average Porsche Cayenne enthusiast?
$300? Betcha' it would sell like hotcakes.
09-24-2016, 10:22 PM
#24
Electric heaters are fine ideas but they work on the premise that an electrical supply will always be available where you park up (which as we know isn't always the case) whereas the Webasto is good to go anywhere
09-25-2016, 03:22 AM
#25
Banned
Join Date: Mar 2011
Location: Spring Lake, NJ, US of A
Posts: 10,085
Received 1,150 Likes
on
763 Posts
Whatever fuel the vehicle runs on - it is supplied from the main tank
Electric heaters are fine ideas but they work on the premise that an electrical supply will always be available where you park up (which as we know isn't always the case) whereas the Webasto is good to go anywhere
Electric heaters are fine ideas but they work on the premise that an electrical supply will always be available where you park up (which as we know isn't always the case) whereas the Webasto is good to go anywhere
09-25-2016, 05:20 AM
#26
Instructor
Block heater which will work
I have recently acquired a "WP1AB" Cayenne S. We live in a cold area. I plan to snuggle "Ruby" up next to a wood-fired box stove in an insulated garage for the winter. I'll leave the Lexus ES outside for the dirty work and use the Tacoma for heavy going in snow.
Last edited by Rod Croskery; 10-02-2016 at 10:40 PM.
02-01-2018, 08:34 AM
#28
I personally think that 20-25% is going to end up being way down on the low end by the time all of these cars start to get more miles on them. I think most of the V8s will fail from this eventually. It is a manufacturing defect that Porsche refuses to own. I really think they will probably all die this way eventually. If it has a V8, I would assume you are always on borrowed time. I love these cars but the motor issue makes me glad mine is gone.
02-02-2018, 12:32 AM
#29
Rennlist Member
I have a s/n WP1AB......
Engine replaced before i purchased the vehicle.
At approx 90k km (56k miles)
Engine replaced before i purchased the vehicle.
At approx 90k km (56k miles)
02-02-2018, 01:11 AM
#30
Burning Brakes
What I find interesting is that scored cylinders isn't just a Cayenne thing. Been looking at the Cayman and 997, and it seems like cylinder scoring in cold climates is more common than the IMS debacle!
Maybe it's just the rarity, but has anyone ever heard of a GTS or Turbo S with scored cylinders? Right now it seems like the '08 (N/A and Turbo) are dropping like flies.
Maybe it's just the rarity, but has anyone ever heard of a GTS or Turbo S with scored cylinders? Right now it seems like the '08 (N/A and Turbo) are dropping like flies.