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Hi everyone. Long-time lurker, and this forum helped me get comfortable/excited about buying a used Cayenne. Thanks!
I need advice. I just bought an 08 Cayenne S in North Carolina from an independent European car dealer & service center, right before Thanksgiving. Has just 53,000 miles on it. On purchase, I had an alternative European car dealer inspect it, and they said it looked good. Also, the seller replaced all 8 spark plugs, and gave me new tires, at time of purchase.
A few days after buying, my wife, kid, and I drove it about 180 miles on the interstate, and the CEL came on -- not flashing. I also got a message saying the Oil Level was low, but looking at the dipstick, it was between MIN and 1/2. We finished the trip (another 200 miles), and exactly 1 week after buying it, I took it back to the independent dealer/service center I bought it from to look at the CEL. They said it looked like the last owner didn't drive it much, and maybe didn't use premium fuel, but I was good to go. They cleared the warnings.
72 hours later, after driving another ~400 miles to visit family for holidays, the engine starts misfiring and the CEL is flashing. Luckily, this happens as we're pulling into my in-laws neighborhood and I drive it just another 0.5 miles. I call a Porsche dealer nearby (Porsche Southpoint in Durham, NC) and they tell me it's fine to drive it to them (about 14 mi) with the CEL flashing, and to bring it in. So, the next morning, I do.
They say I'm misfiring in cylinders 1,5, and 8. Cylinder 8 is the bad one -- tons of misfires in the diagnostic scanner. Spark plug on 8 is gross, totally oil flushed. The other two (now) don't look new. They advise replacing all engine coils plus spark plugs (again). I replace the coils, and only the spark plug on 8 that's gross. $960. Car seems fine.
I drive it back to my in-laws' house (14 mi). No problems. 2 hours later, I drive it 1.7mi to a restaurant, and no problems. But near the end of the 1.7mi trip back to my in-laws', it starts misfiring and the CEL immediately flashes.
My Cayenne never got driven again. We transported it all the way back to the independent dealer/service center. They are telling me that Cylinder 5 is misfiring badly, and on visual inspection it's because the piston is "melted". They thought that perhaps I drove on it too long with the CEL flashing and that the fuel, directly-injected into the cylinder, was too hot and caused the damage to the piston.
They haven't given me a proposed solution or cost yet. They've been quite responsive and helpful. I asked what the worst case scenario is, and he said "replacing the engine would be the easiest thing". So, 10 days after buying it, it might need a whole new engine.
I called Porsche Southpoint again today to see what they thought. They emailed me the codes from their diagnostic. They still didn't think I drove on it too long if I was describing things correctly.
I really don't think it was misfiring without me noticing it... my wife was with me, and she does *not* miss or ignore stuff like that. We both noticed and commented on the misfiring at the same time. And very little driving was done after the engine coil replacement.
What do y'all think? What do you suggest needs to be done? Any suggestions for me, as a consumer who appears to have a major problem on his hands?
Those plugs are dirty, but they look pretty new. Notice how the tips of the electrodes still have sharp corners (not rounded). Tell me again why the seller replaced them....
10 year old car with 53k miles, it was driven 5k a year - not a lot, may be this is the bad thing.
No one probably checked for cylinder scoring ?
Sounds like you should try to find a used engine.
On an S, there is absolutely NOTHING wrong with using non-premium gas, other than you get slightly less maximum horsepower. It will not harm the engine or fuel system in any way. If the cylinder really is "mented" on top, the only thing that could probably do that is running very lean... that could make the cylinder very hot. You may have a problem with the fuel injection system. Most likely for the cylinders that are showing bad misfiring. That could mean the solenoid on the injector that allows the injector to spritz fuel into the cylinder is sticky so you don't get enough spurts of fuel each time (in the affected cylinders). The big problem with this diagnosis, though, is that the spark plugs don't seem to show any of them having been in an ultra-lean cylinder for any length of time. You might get more help with this if you list the error codes along with the text translation for each one. Of course you really haven't driven all that far with the misfiring happening, so it's possible the plugs just haven't been exposed to an ultra-lean condition long enough to change their appearance (a plug in an ultralean cylinder would be almost "white" around the electrode and there may be white powdery-looking deposits on the tips of the electrodes and on the center electrode insulator. Spark is not the only reason a cylinder misfires, but it sounds like the shops you went to all are treating this like it is a spark problem rather than a fuel delivery problem. But there may be something in the codes that kept pointing them at spark rather than fuel... which we haven't seen yet. So we are all a bit "blind" on the problem without knowing more about codes and their text descriptions.
Did you ever happen to try stopping once the misfiring starts, turn the engine off, then restart to see if the missing is still there? A vacuum leak into those cylinders could cause a lean condition also. So they really need to do a compression test on the cylinders you have been having trouble with to see if the cylinder holds pressure or leaks down. If the cylinder leaks down under compression, you have either scored cylinder walls or warped valves (or both) that prevent the cylinder from completely sealing when all the valves for that cylinder are closed. Ultra-lean running causes the cylinder to get very hot and that heat can warp valves and melt tops of pistons. If the cylinder walls are scored, you really would be looking at a new engine. Finding a used 08 engine with circa 50,000 miles on it may not be easy. Cylinder scoring is more common if the vehicle has been in state with very cold winters... the scoring appears far less often in cars from warmer areas. If the Carfax report indicates the car had been "up north" for a portion of its life, there could have been scoring issues. Oh, and ultra-lean running will also damage spark plugs if the temperatures are high enough to warp valves.
Driving with a check engine light should not cause the the issues you are experiencing.
The dealer that inspected this did not do a compression check or inspect the cylinders for scoring. The melted piston is likely cylinder scoring which is causing the plug to foul. This does not happen in a few hundred miles.
The cost to replace the engine will likely exceed the market value of the Cayenne. Return it to the seller for a refund is the best option, even if you loose the money spent to date.
another thought - is how did it get to 50k miles? Was it driven often?
it's roughly had 100 tanks of gas in last 10 years.
If it sat for a long time - gas can go bad and gum up injectors. Or seals can dry up and crack.
vandal968, they replaced the spark plugs to encourage me to buy, since it's coming up on 60,000 miles and the plugs would likely need changing.
ScootCherHienie, yes, I tried turning the car off and back on. The misfiring would still happen unless the car sat for several hours. If it had sat, the misfiring would return in as little as a minute to as long as 5-10 minutes. Here is a link to the diagnostic codes/report that the dealer emailed to me: https://www.dropbox.com/s/2u1lhqjlxi...15410.pdf?dl=0
Everyone, yes, this car was owned in NJ and Pennsylvania before coming to North Carolina. The mileage came pretty steadily over time, so just not a lot of driving. What would you expect a European car dealer to check before selling it? Sounds like a compression test is something a dealer should do? If the cylinders *were* scored, why would it take a few hundred miles of us driving it before the misfiring started?
Given the oil on the spark plugs... was it reasonable for them to look at those and think "oh, just old"?
Does anyone think there is an implied warranty since they serviced my car as well as sold it, and they had just looked at the car's CEL causes 72 hours before the misfiring occurred?
Did they show you photos from a borescope camera? As Scoot mentioned, those plugs show no signs of a lean burn.
I've never heard of a Cayenne melting a piston and the scored cylinder issue has nothing to do with a melted piston top. Also, a scored cylinder results in very loud ticking, well before the car starts running poorly. If the top of the piston is damaged, I'd suspect something dropped into the cylinder during the first spark plug change. An injector dumping raw fuel could cause hydrolock, but that usually causes damage lower down, like a bent connecting rod.
A photo is worth a 1,000 words. Even if you have to snap a photo of it on your phone, post it here.
btw, don't concern yourself with weird things like low mileage.
No, I haven't seen pictures from a borescope camera. I'm not a car person, but before we bought it there was a clicking sound coming from the engine. Seller said that's a normal direct-injection click. Nothing you notice while driving, just while standing outside the car.
Thanks again for all of the input! Let me know if there's anything else I should ask/look into while we try to work this out.
Does anyone think there is an implied warranty since they serviced my car as well as sold it, and they had just looked at the car's CEL causes 72 hours before the misfiring occurred?
Every state is a little different. You are out of factory warranty and Porsche is not going to help. Many states mandate a 30 day 3000 mile warranty on used cars, depends on your local laws.
Let us just be brutally honest. This is almost certainly scored cylinders. The person who traded the car off knew. The selling dealer may very well not have known, you probably would not unless you did some research. Most car salesmen and even used car managers and buyers are not savvy enough to know a car totaling problem like this exists or they would not take the risk they did by selling it to you. I would do everything in my power to return that car. I would find out what laws there are since it happened right away and was clearly pre-existing.
Buying a V8 Cayenne that has lived in a cold climate is risky. Buying a used one regardless of miles without a bore scoping is risky. New plugs should have been the first red flag if you had researched here much. I think all of these engines will fail this way, most before 100k miles. You just got one of many lemons produced by Porsche. Their lack of support on solutions is the most disturbing. That is what drives the cost of the repair through the roof. The repair you face will cost more than the car by the time it is complete. The Cayenne is a risky vehicle to own. Rewarding when it works properly, expensive when it doesn't.
ScootCherHienie, yes, I tried turning the car off and back on. The misfiring would still happen unless the car sat for several hours. If it had sat, the misfiring would return in as little as a minute to as long as 5-10 minutes. Here is a link to the diagnostic codes/report that the dealer emailed to me: https://www.dropbox.com/s/2u1lhqjlxi...15410.pdf?dl=0
You have P0308 code - misfire in cylinder 8, so likely something was going on for some time.
12-03-2017, 12:14 AM
Did I buy a lemon? 08 Cayenne S, need help
