I'm no expert in Cayenne cylinder scoring but if I'm correct, scoring is the results of many things. There is the cold start aspect but turbos don't suffer from scoring even when in cold climates but n/a engines do even on warmer environments so I don't think that is the major cause. Second thing are the cylinders themselves that are lokasil(?) coated, again turbos are different with nikasil(?). Thirdly there is the lack of oil sprayer jets under pistons, turbos have them, N/A engines do not. My thinking is that the lack of oil jets in conjunction with the lokasil is bad enough. Cold starts only accelerate and worsen the wear. I don't know of any other way of pre-heating engine oil than those cooking plates that attach to oil pan, probably none available readily for Cayenne.

This isn't any gospel, just my current understanding of the matter.

 

I see. I once saw a Hyundai Pony run at redline that had been treated with Slick50 and then with all the old drained. At least 5 mins before lockup. I would not have believed it but I was there and the event was a called "motor blow" (don't ask). I wonder if there is an additive that really assists in keeping these old 4.5s from scoring.

 

Turbo engines have suffered cylinder failure.

https://rennlist.com/forums/cayenne-...l#post15569072

 

A while back I came across a article where VW (or another German manufacturer, as MB and BMW were also using lokasil/nikasil engines and had scoring issues) where they concluded that the scoring was mostly the result of fuel quality. But, for the life of mine I have not been able to find that article again.
Basically, fuel quality in Europe is better than in US, and the engines were developed on that fuel. I don't think cylinder scoring is a much an issue even in colder parts of Europe.
Then cars started selling in US and the problems started appearing. Cold climate thing is also tied to fuel, too - pump gas is blended differently for cold weather, and it may be the winter additives that are causing scoring more than the start temperature.
In Russia, where quality of fuel is very poor, cylinder scoring is much more common than in US. But then again, it's also colder there, so who knows if it's temp or fuel?

 

I think I'm subscribing to this thread..

 

You're absolutely correct, I didn't mean it like that. What I meant to write was that turbos do not suffer from it as often.

 

@slavie , that's a good point about the fuel. I wonder if there are any additives that could be used per tank that may improve the NA fuel quality. And Turbo engines have a different piston material and cylinder coating as far as I have read but that does not seem to be the link here. I wonder how many of the failed engines were abused. Driven hard when cold. Running oil too long or crappy bulk oil from minute lube. How many failed engine's cars have tow hitches installed? Maybe the longest running engines have been treated the best and the early failures were poorly maintained over worked. How may of these engines that failed were lease vehicles where the first real owner was after 30K miles. Be interested to know how many owners with failed engines followed all the rules from day one and can say that they were there from the beginning.

 

It was Jaguar.... Higher sulfur content + Colder climates


Complaints arrived outlining complete engine failure and, more often than not, these grumbles usually came from clients abroad – especially in the U.S. Naturally, Jaguar had carried out meticulous tests during the development of the XK8, but these had been carried out using fuel with a low-sulphur content, typical of that sold within the UK.
Meanwhile, the increased sulphur concentration in fuels abroad had led to the formation of sulphuric acid within the XK8’s V8 cylinders, which anyone with an enthusiasm for chemistry will tell you is a recipe for eventual disaster. The sulphuric acid ate away at the Nikasil lining, allowing the piston rings to score the cylinder walls and lead to low compression.This disappointed Jaguar immensely, for this was the very problem they’d been trying to avoid when opting for Nikasil over aluminium linings. Engine failures sprung up most readily from within Jaguar’s export market but, eventually, the UK demographic began to suffer too, as lower environmental temperatures also gradually contributed to the formation of sulphuric acid and its unfortunate effects.

 

 

In Canada sulfur in Gasoline was reduced in 2005... Interesting timing.

1. Sulphur in Gasoline: Regulation Changes in 2005
   
   In 1999, the federal government imposed a limit and an accompanying time frame for sulphur concentrations in gasoline. At the time the average sulphur content in gasoline across Canada was approximately 320 parts per million (ppm). The regulations required a decrease to 150 ppm from 2002 through 2004, ensuring that by January 1, 2005, the average concentration would be 30 ppm. Table 1 shows the amount of gasoline produced and imported in 2003 (excluding aviation gasoline) and the amount of sulphur it contained.
   
   As described previously, this decrease in sulphur content will result in decreased sulphur emissions and also allow for better after treatment systems, thus also resulting in a decrease in other harmful emissions.
   

 

Over the years I've read more bore score horror stories on the turbos. There's also a bore score survey in the stickies...it's a small sample, but more turbos have been reported.
There was a very active regular who went by wrinkledpants that made dozens (if not hundreds) of posts claiming the turbos were immune to scoring due to the different coatings, oil jets, blah blah. Obviously not true at all but his ramblings turn up as top hits when searching the subject. He disappeared one day...probably after hearing the tick of death under the hood of his immune turbo.
fwiw the '08 turbo seems to be the worst. You can find examples like this just about any day of the week:
https://vancouver.craigslist.org/nvn...005536551.html

 

Okay, so got a scope down the spark plug holes and it's not so pretty. It was too cold out to be figuring to how to capture photos with the cheapo camera I purchased. But it did show me that on several cylinders the walls are at the very least scored. I would say more like eroded. Large patches and gouges all over the place. It's no wonder it binds up. Anyway's off to pick up a replacement engine a next weekend. Thanks to all that commented.

So, let's say the new-to-me engine runs nicely with no ticks. Are there any lessons learned over the years regarding preventative measures? Other than sell it quick? Oil additives, Block warmers Sulfur-be-gone fuel additive??

@19psi I test drove that Cayenne in Vancouver last summer. At least one dead hole and gutless. Very clean though being a Vancouver car.

 

I don't think there really is any definitive answer to the cause of the bore scoring or additives that will help.

The most reliable information on the issue I think comes from 2 main sources:
1 is the survey deilenberger did. It provided some of the only actual data on the issue. It also dispelled the myth that the turbos are immune or less likely.
2 is the various experts that frequent these boards. People like Jack Raby who make a business out of rebuilding, modifying and studying these engines and many others.

I think the current leading theory is that the issue is the result of bad tolerances during a finishing/honing process on the blocks. Porsche adjusted the process sometime in late 2008, and it's currently believed that late 2008 on wards are relatively immune resistant to the issue. You can check based off your VIN#. So far there haven't been any reports of those engines suffering from the issue.

I think its also worth noting that pretty much all Porsche engines (911s, Boxsters, Caymans, and Cayennes) were suffering bore scoring issues between the early 2000's up to 2008. After 2008 it seems the issue is much less prevalent across the entire lineup. I think the VR6 was a VW design and as a result the VR6 Cayenne's are fine, the Mezger engines in top end 911s are from a previous generation of engine designs, and some other engines might have been safe too.

Not directly applicable to our engines but my gut tells me many of the same reasons apply:

 

So we know that by the beginning of 2008, 200,000 Cayennes were built.

By 2008
On February 4 in the 200,000th Porsche Cayenne rolled proudly off the assembly line in Leipzig, Germany. The model was a Cayenne GTS, which was unveiled that month at the Chicago Auto Show and launched that spring.


We also know that almost 85000 of these were sold in the US. Assuming that 50% (SWAG) were V8s, that's over 40000 V8 Cayenne's sold in the US from the 2003 to 2008 model years.

If this is the case, odds would have it that owing a 2003 to 2008 Cayenne V8 is not the "time bomb" some make it out to be.

 

BMW also had issues due to high sulfur content in US fuels in the mid-90s with their Nikasil cylinder liners. The one most affected was the 3.0L V8. The 4.4L may have been affected as well. Lots of them got replaced with Alusil engines.