What are the signs of a failing turbo?

In the last 200-300 miles, the car has exhibited some worrying symptoms. I drive the car for 15+ highway miles, let the car idle for 2 minutes and shut down. Start the car 1-2 hours later and about 50% of the time I get a fair amount of visible "smoke". The conditions are relatively unique and my hunch is turbo failure.

Initially there is no immediate smoke upon warm start up. Count to 2 or 3 and suddenly an excessive amount of poorly mixed smoke wafts out for 5 seconds or so. It really resembles a blown out candle, not at all like an engine burning oil which is a uniform haze out the exhaust. The color is more white or light gray than blue or black. The smoke is only from the left exhaust pipe, the right produces nothing (ever).

Cold start or mild town driving does not produce any smoke on startup. In fact, I don't ever recall seeing any smoke on cold start. The left exhaust tip has always gotten black rather quickly compared to the right side. Been that way since I bought it in 2009.

Car boosts to 0.8-0.9, but I also just today noticed a visible haze in my rear view mirror at WOT. Saw that, finished my commute, and will park it until it goes to the shop.

Car is 2003 x50 with 120k (gets driven a wee bit) and has new coils, plugs, and maf in the last 4k miles. Completely stock engine with original tune.

If it is a dying turbo, can they be rebuilt or will I need new replacements? Can different compressor wheels (like 18g) be run safely with the stock tune or is an aftermarket tune required? Clearly an aftermarket tune will extract more from reworked turbos, but I am worried about starting down a very slippery slope...

 

What exhaust do you have? How is your coolant level?

 

Mine smokes a little on the left also after the same conditions (drive it a bit, or a lot, let is sit like an hour/wash, restart, little smoke on the left). When I hammer it moving I've been told it smokes a little from both sides but that is at full boost. I've been told a lot of different reasons why it "could" be happening. I say if the car drives okay, no leaks, doesn't use oil really, why create work?

 

because a slow coolant tank crack and slowly(?) leaking coolant turning into coolant steam, won't get better on its own.

if that what it is.. sounds lilke coolant.. not oil, creating the light coloured steam you're ( the OP is ) seeing. just a guess.

 

If he means driver's side, coolant leak could definitely be a possibility especially since there is no smoke on cold start.

 

No noticeable coolant loss for 2 years now. Had the system flushed and it has held steady at the max line on the coolant reservoir since then. Will watch it though.

Oil consumption is 2 individual bars per 2500 miles. Have not seen any changes to this rate recently.

Exhaust is stock.

 

Would a failing turbo cause any noise? When my supercharger went out, it caused a terrible whining noise.

 

it's the location of the "steam/vapor" that *might* indicate it is coolant. not saying it is, or isn't,.. but it's a likely source of past coolant loss ( steam out drivers side ) leaking from expansion tank..so common, it had to be mentioned.

but tim was helping you before i stuck my nose in . so perhaps he'll help you further. gl and keep an eye on it is right!

 

When the turbo started to yak on my previous turbo cars (talon, rx7) they would leak oil from the cartridge to the exhaust housing and smoke occasionally. Not sure if that happens on 996tts, I think turbo failure is unlikely as some guys have lots of miles on their stock turbos.

At start up I get condensation from the exhaust when cold but it goes away pretty quickly but not smoke. You're sure its oil or coolant, you can smell their distinct smells?

 

For mine, yes, drivers side. Not coolant; unless the car is self topping off. Its either a de minimis amount of oil or fuel. Again, if its not losing fluids, running good, not making noise; I'm not going to tear the engine down looking for something that isn't an issue. Its just my position, my statements are not to be mistaken for advice or profession guidance.

 

that's one hell of an illogical leap from investigating the cause of smoke emanating from the rear of the car to.. "tearing down the engine".

you'll often find as you spend more time in here posting, as many of us do ( ad nauseum, no doubt )..

that what you post is often construed as "advice", whether you intend it to be, or not. lol. i'm also sure that anyone that reads what either of us post, would never assume it was "professional guidance" ..not even close lol

 

Just trying to give an alternate option to "the sky is falling, your car/turbo(s)/engine is going to grenade at any moment, must spend money".

I'm not sure how one would investigate a "potential" small oil/coolant leak without removing engine components and risking more leaks. Again, if its not leaking, or loosing fluids how does one investigate without internal inspection?

Good luck to the OP! Please update if you proceed with a real investigation (non web forum advice) and the cause/solution is found. I for one would honestly love to hear.

Z

 

If you suspect some sort of fluid leak, you can add a bright red coloring to it. Doesn't hurt anything; just makes it very obvious when it does leak.

 

no one in this thread suggested anything remotely as dire as the possibility that the "sky is falling". also, i think you'll find ( if you spend "enough" time here ) following the percentage of issues relative to advice received? you justmay find there is very high rate of accuracy. i attribute that to the experience gained from having owned the cars for years. some issues crop up with regularity. eg. leaking coolant tanks that can cause the SLOW loss of coolant, often resulting in coolant loss as vapor from the drivers rear side.

i learned about that on an internet forum.. just like this one lol.
so if you don't feel your input or "advice" might be helpful? here's some from me to you.. don't post any! because suggesting somone ask someone offline ( as opposed to genuinely seeking advice from other owners..) is usually "last resort" kind of advice. these forums exist to trade info/advice and anecdotal experiences. it's up to you, and
others, through discernment..to separate the wheat from the chaff, as it were

 

You're right, given my limited forum experience I should probably not share my opinions. Thanks for the lesson.