Not sure how many 955 owners still reside in these forums, but I wanted to ask who has had or heard of turbo failures on them? Digging around online you really can't find much about turbos going bad. I've seen a few reports of cracked housings and leaks of various kinds, but even those seem quite few and far between.
Given this, and how many ultra high mileage early CTT's still seem to be kicking about out there, I can only assume the IHI units they came with are somewhat bulletproof?
I can't find any cases of actual rotating assembly turbocharger failures, but of course that's not to say it doesn't happen.

The main reason I ask is because I may have been unlucky enough (still waiting to confirm by doing a trans pan gasket job) to have my torque converter seal fail on my 200k mile car. Real bummer as other than this it's a fairly well sorted car and drives pretty nicely. I've done a bunch of work to it and knocked out most of the other major jobs.
I'm on the fence about doing an engine out to fix it as it will be a lot of money to sink into an old car that's not worth much. Obviously there are a bunch of "while you're in there" jobs that will blow the cost out even higher, and I'm wondering if turbos should be on that list. Of course, in a perfect world I'd do a full engine rebuild and replace every component, but I'm trying to keep this realistic and not go down the rabbit hole of replacing everything that doesn't necessarily need it.

 

Haven't seen very many actual failures. Some.of what was thought to be turbo failures early on were people mistaking oil in the driver's side intercooler as a turbo failure when it was really just PCV system oil vapor condensation.

 

About as common as finding a duck tooth. If you pull the engine, definitely replace engine mounts. Might check condition of cats and flex pipe for possible replacement.

 

Does it matter if they are broken? The shop manual says not to replace stock parts, only upgrades. You definitely need these $3.7K upgraded turbos on re-install.




on that list of "while you are in there" might also be:
- coolant lines, especially o-rings that inevitably fail on the smaller coolant lines.
- core out secondary cats by cutting open like a coffin and re-welding from top
- motor mounts
- subframe mounts?
- torque arm?
- belts/pulleys?
- check/tighten variocam bolt
- pre-emptive starter replacement
- walnut blasting valves
- coils/plugs
- smoke test on turbo vacuum and control lines, and on intake pre and post turbos
... I'm sure there is more


cheers, and good luck

 

Those are for the newer Cayenne Coupes, not our cars. But turbo upgrades are cooooool.

 

This logic only applies if you plan to sell. When your car depreciates, it doesn't lose it's value as your car, it just means that the 'market' won't pay that much for it anymore. Only you know if dropping $5k into a vehicle is worth it because it will keep in on the road for another 10 years, etc. It doesn't matter if your vehicle is worth $20K or $20.

 

Very true, I think that's a much better way to look at it.

If I knew that replacing the seal would mean that the car would be good for another 10 years or 100,000km I would not hesitate to do it, but I'm sure there are numerous other issues which may crop up which is where making a decision gets more tricky.

Going to get some quotes on a full engine and trans drop and see what sort of figures mechanics in my area are asking. If they're crazy prices I might stick some stop leak in the trans and see how it goes. If that fails I might just park it up and let it sit for a while and maybe DIY it in the future. If it were a generic CTT I would be more keen to offload it, but it's a really nice spec with quite a rare interior colour. It was also previously owned by someone pretty high profile here in Australia which makes it somewhat more of a collectors piece I suppose. Not to mention I've already spent a bit on it, so yeah I'm not massively keen to let it go.