tassieporsche

I've just picked up a 2004 CTT with a few issues and am starting to dive in and peel back the layers of the onion so to speak. The car runs and drives, but it needs a valve body replacement (I knew that when buying it).
Right now, what I'm more concerned about is diagnosing some engine issues. After going for a short drive, turning the car off and then starting it again, it blows a very large plume of white (maybe blueish but hard to say) smoke out of the exhaust. There are also lean running at idle codes for both banks. There are what look to be numerous oil leaks, mostly coming from the left hand side of the engine (drivers side for those of you in the US). The PCV valve on the top of the left valve cover looks to be where one of these leaks originates from. Based on the issues that are present, I'm hoping the PCV/AOS is the culprit and not something more serious.

There looks to be a very slight amount of oil in the coolant expansion tank, not enough to make it look like a milkshake but just enough to discolour the water and make it feel slightly greasy if you drip you finger in and rub it on your hand. No signs of water/coolant in oil though thankfully. Hoping this might be an oil cooler thing?

Would love to hear from some more experienced people who have been through these issues before and can easily identify the causes. This is my first Porsche, I've come from the land of BMW, so I'm still pretty unfamiliar with this VAG ecosystem and have a lot to learn.

brett968

I remember your first post about buying this car and from the sound of it, there has been a LOT of deferred maintenance and repairs. You are going to have to perform these missed repairs to bring the car back to a reasonable, not to mention reliable, state of function. STEP 1: The first thing to do is determine whether the car has a fatal fault and is even worth the time and effort to repair. You need to rule out cylinder bore scoring and figure out why there is smoke coming out of the exhaust. I suggest you post a video of the engine running and maybe a shot of the tailpipe smoke. Hopefully the smoke is just due to a bad AOS but it could be turbos or head gasket. The oil in the expansion tank is very concerning. Why don't you post a pic of it here so we can give you our opinions?

This is one of those scenarios where I don't think it makes sense to try to pinpoint the individual smaller problems and focus on fixing those. The car needs an exhaustive service. If you don't have documentation that a service item has been performed then assume it wasn't. This will take care of most all of the smaller complaints. Some of the things I would replace include spark plugs, coilpacks, valve cover gaskets, AOS diaphragm, all filters and fluids, all of the common cooling failure points (this means removing the intake manifold), water pump, accessory belt + pulleys and tensioner, etc., etc. I suspect the engine mounts are collapsed, and we haven't even gotten into suspension or brakes.

Even if the car doesn't have some fatal fault, unless you are resourceful, are mechanically inclined, and have the time and tools to perform most all of this work yourself then it is not going to be worth it to repair this car.

Libast

With that many miles, valve guides might be worn just enough to leak a lil oil into the cylinder.

But yes, my AOS on my 2009 CTTS with 220k miles failed spectacularly

hatchetf15

OP - What Brett968 and Libast say is spot-on. Get the Pepper to a baseline. Smoke that hangs around and, well, smells like burned oil is most likely oil. While you address all the items needing attention, it’s very likely you’ll catch the culprit(s). From my experience, intermix is very rare on the 955. Valve covers will leak and smell, and eventually smoke a tiny bit under the hood. AOS diaphragm can be replaced. Drain the oil from the left side lower turbo hose, as per diy instructions. That can cause smoke.

Libast - Wouldn’t passing a compression test rule out valves?

As mentioned, a few photos, video of the areas you’re investigating would be helpful. Happy wrenching!

Libast

Longer duration one for sure. But oil is oil, and sitting overnight might be enough to sneak by even a mostly air tight combustion palace

tassieporsche

Thanks for the replies guys. Here's a photo of the coolant. Upon giving it some more thought and speaking with a friend about it I don't think there's actually any oil in it. It's just old and discoloured coolant and the slightly greasy feeling when sticking in your fingers and rubbing them together is just the glycol. Looks clear when on your finger too so no milkshake happening. Phew.
I'm having the car looked at tommorow by an acquaintance who used to be a Porsche mechanic, hopefully he can shed some more light on what needs work. Surposing the smoke is from the AOS (which I'm confident it is) I don't think the engine has any fatal flaws, just needs a lot of TLC and all of the deffered maintenance completed.

Oil in the lower turbo hose is something that I think is contributing to the smoke too. What is the reason for oil collecting in this area, and is that a normal thing to occur?
Also, is it correct that CHF11S or 202 is the correct power steering fluid for these cars? This seems contradictory as these are synthetic fluids but the cap on the resovoir says mineral fluids only...

Sorry for the lack of photos, I'll try to post more as I go on. Will report back once I find out more about where the car sits tommorow.

Libast

Draw some of the coolant out with a straw and put it on a paper towel. Should be light-ish pink.

The AOS on 955/957 was not designed well and is prone to failure and ineffectiveness.

Bbbb Bbbb

Oil in the driver side lower turbo hose is normal. I believe Porsche even advises to drain & clean the lower intercooler hoses at 20k intervals. I do mine every oil change for good measure.

tassieporsche

So after getting the car looked at by a Porsche trained mechanic yesterday the news is good.
As I'd hoped, PCV failure is causing the lean codes and smoke from the exhaust, not to mention generally rough running. Does anyone know a good place to buy the parts for this? I've looked around a bit but have only found dodgy-looking Chinese sellers on eBay and such. Shipping to Australia will be required.

Other than the PCV, the only other two urgent issues are the park brake cable which has bound up and does not release properly, and of course the gearbox valve body which I knew about when purchasing the car.
The mechanic also mentioned I should check the valve clearances as burnt exhaust valves are not uncommon on these engines.

Keen to get these three issues addressed ASAP and start driving and enjoying the car.