I was wondering if it is common for our turbos to leak.

it is coming from the driver side and I looked down air hose pipe that connects to the turbo and looks wet.

somthing repairable without taking the engine out?

it is only on the driver side. Dry as a bone on the passenger side. Intake looks very oily along with the maf sensor.

i did replace the aos about 10k miles ago.

 

Bump.

has anyone changed seals or taken the turbo out without dropping the engine?

 

Jay - did you clean out those lines when you changed the AOS out? Did you clean out the intercooler? This might be residual leftover from your old AOS.

To answer the question you asked.. someone once did remove a turbo without dropping the engine. He didn't recommend anyone else try doing that. The turbos are standard ones and new ones aren't awfully expensive, but if yours is leaking it's a real outlier.. so far failed turbos? I can recall maybe one, and I think that one ate a vane for some reason or another.

 

I cleaned the intake hose that goes to the throttle body and also the throttle body. I also performed a intake cleaning with bcg (like seafoam)

after about 15k miles I notice oil again. Saturated in the hose and bottom of the throttle body. It is wet.

could it be a failed aos again?

i did not clean out any of the hoses going in and out of the aos

if the turbo is leaking you said it’s pretty obvious? Should I stick a camera down the pipe and see if there is a puddle of oil at the turbo?

 

If the turbo is leaking - you'll get smoke. The leak would be into one of the turbo chambers. One is the intake, the other is the exhaust side.

Dunno on the AOS, they don't seem to be a common 958 CTT problem except for the very early ones which were a defective design (2011 models.), I think cleaning out everything would be worthwhile. Then run it a while and take a look to see where any oil might be.

BTW - most things injected into an intake like BCG or Seafoam are pretty much useless. They're basically a light solvent (naptha) with some "magic" added - the naptha does the actual cleaning, but it will not take away puddles of oil. The cars with the defective AOS's had oil buildup in the plumbing around the intercooler on that side, bad enough that it would leak out at the joints - and the intercooler might have 1/2" or so in the bottom. No intake cleaner is going to do much for that, you need to physically disassemble and clean out the parts (especially the intercooler - it's the low point in that section) to really eliminate the oil.

Probably getting the plug-in boroscope for your smartphone might also be helpful in diagnostics.. the one I have is "Pancellent" - Amazon for not a bunch of money. Works fine.

 

My 2011 CTT had a slight oil leak that was diagnosed by the dealer as failed seal(s) requiring a new turbo. Fortunately warranty covered it. This was around the 60k mile mark IIRC. I think mine’s one of very few 958 CTTs I’ve heard of requiring a new turbo however. So it seems to be rare, but can happen. It remains to be seen if this might become a bit more frequent now as these 958.1s get up there in age/mileage.

As you may have noticed, as happens with most auto enthusiast forums for any make over time, this 958 forum is moving more in the direction of a ‘how do I fix....’ forum versus more general discussion/enthusiasm. So things that we haven’t seen much in the past might become more frequent...time will tell. Overall though thus far, these seem to be pretty robust vehicles in the grand scheme of things.

 

Don’t see any smoke other than a quick puff of white smoke from a cold start sometimes.

ill try that and I’ll stick a camera down there to see if anything’s up. I dig more digging and it looks like the aos doesn’t do a good job. Other members with 957 cars end up adding 2 additional catch cans. Thinking of how I would do the plumbing.

Took the intake off for a coolant repair so I’ll be cleaning the valves by hand. Hopefully it will stay clean for a bit

 

I also have a leaking cap on the valve cover
i took the cap off and was wondering can I replace this seal without taking the valve cover off.

also been searching but I can’t find part numbers for both sides.

odd no one has had this issue

 

I recently cleaned out both intercooler pipes and got a new aos (new design). I’ll check the pipes again at next oil change.
i had it on both sides though.