Before I go through the hassle of ripping everything out, paying to get things rebuilt, then reinstalling everything (not to mention I'd rather spend the money on something else, like some ID injectors), I need your guys opinion. Is my turbo on the way out?

Facts: Stock Greddy T518Z running stock boost (8lbs max), roughly 11K miles on the turbo, 10W30 Valvoline synthetic changed at time of turbo install 1,000 miles ago, then changed again about 200 miles ago just to be sure. Bought the kit used from a guy who had it sitting in his garage for almost a year after he sold his car. He put 10K miles on it and changed the oil every 3000 with 10W30 Mobil 1 synthetic.

Why I'm concerned:
Occasionally, while at idle, I'll get a healthy plume of whitish smoke out of the exhaust. It is random and unpredictable. I'd say it happens maybe once during a 30min trip in normal traffic. All other times, it doesn't smoke at all. I've also noticed a faint humming sound that seems to rise and fall with my RPMs, but when I pop the hood and modulate the throttle, I don't hear the humming coming from the turbo. In fact, I can hardly hear the humming at all when outside the car. It seems to be the loudest on the inside, near the passenger side footwell area. It does NOT sound like the "weeeeeoooooooo" turbo-death sound that you can find in Youtube videos, but I have no idea what it is.

Everything else appears to be working. I get a full 8lbs of boost at WOT in 3rd gear, the car pulls normally, dyno'd normal Greddy numbers a few months ago (271whp/205ftlbs), and is not burning any oil (I check this after EVERY drive just to be sure). If it weren't for the random smoking at times, I wouldn't even think anything of it. I should mention that with my tune, my car does run a little rich at idle (high 12s-mid 13s on the wideband), but I know that is a tuning issue that will be corrected when I get the new injectors and retune.

Thoughts?

 

How do you have your oil drain setup?

 

I'd just keep an eye on it and plan on rebuilding the turbo if the white smoke becomes a constant problem.

 

The way Greddy says to set it up in the install instructions. Line to the drain plug on the oil pan with the provided adapter.

 

I know a few people have been having problems with the oil return line being in the drain plug hole. The oil can't get back into the pan very easily and causes oil to back up into the turbo. Also if the line for it is too long it won't return to the pan. (happens a lot when kits are bought second hand.)

 

My Greddy kit made the humming / whooshing noise too. It was the oil going through the lines to the filter. Their relocation kit is junk. Check to make sure the lines are not kinked.

 

A suggestion would be to use a heavier weight and possibly non synthetic (comes to preference) oil.

 

The smoke-thing is unpredictable, but I've noticed that it seems more likely to happen when I come to the first stoplight after getting off the highway. I don't know if that means anything or not, b/c I'm not even in boost while cruising on the highway.

To some of the other replies:
-Yeah, I'm thinking that on my next oil change, I'm going to switch to Amsoil 10W40 and give that a try. I have the blackstone oil analysis kit waiting for my next oil change now so I can get my current fill analyzed.

-I'm thinking the humming sound is "normal," or at least I'm hoping it is. It is not coming from the turbo itself, that much I can tell.

-I was wondering about the oil return lines. I actually have a tapped oil pan... is there some way to "reroute" the oiling system with the tapped pan as opposed to using the drain bolt adapter?

-Part of me wants to just get the thing rebuilt for peace of mind, but again, it's kind of a PITA to do, especially if it isn't really needed. I was hoping not to have to worry about this until at least another 10K miles (which for this car is like 2 years of driving).

 

Smoking when you come to a stop: Could also be due to the style of oil drain and it not draining properly/fast enough.

I doubt you have to analyze the old oil. The heavier oil will help as it wont thin out as much at temperature.

If you have a tapped pan, you should be able to just swap pans and run a new drain hose.

Before you take it off to rebuild it. Check it for shaft play and possible excessive oil in the compressor and/or turbine housing.



Greg @ GO-AUTOWORKS

 

This might be a dumb question, but you can test for shaft play without taking the turbocharger off? What would be the easiest way to do this?