Turbo Going Out?

[DSMboostin15]

I noticed that the other day when I started my car, blue smoke started coming from the exhaust pipe for about a second. I know that it's not the valve seals or valve guides, because I changed them in December along with the head gasket. And if the piston rings were starting to go out, wouldn't the car be smoking all the time, so that's what leads me to believe that it is the turbo seals starting to go out since the car has 147 k miles on it. If anyone can confirm this that would be great. Thanks.

 

[MrBoxx]

Pull off the intake and try to wiggle the compressor wheel in the compressor housing to check for shaft play. There shouldn't be much play at all. If you notice that the compressor wheel moves a bit, chances are the turbo is starting to fail. Check the LICP for any oil pooled in it; another sign of a failing turbo seal. Note: an oily residue on the walls of the LICP doesn't count, since it can come from the valve cover breather and such.

Also it might be a good idea to do a compresion test and/or leakdown test. Most of the experiences DSM'ers have had with a failing turbo resulted in whitish-gray smoke pouring out of the exhaust after a WOT run, after shifting, on deceleration, etc. I don't remember anyone ever saying they saw blue smoke with a dying turbo.

 

[DSMboostin15]

Thanks. I'll check it out later this weekend.

 

[kenamond]

Blueish-white smoke is burning oil. You can get that from a failing turbo (oil leaking around the seals and into the intake/exhaust and burning).

Side/side compressor wheel shaft play is normal. In/out is not. Side/side is tolerable until it starts to rub the housing. In/out is a sign of a failing turbo.

Also, oil in your compressor and LICP is normal, because oil vapor is fed into your intake through your valve cover breather hose (passenger side of valve cover). It builds up over time. If you pull the LICP and intake pipe, clean out the oil (as much as you can reach - doesn't have to be spotless), pull the valve cover breather hose off and cap it (cap the intake pipe nipple), and do a full throttle pull (full boost for a few seconds), then you can check for new oil in the compressor/LICP. You've removed the normal source of oil (breather), so if you find fresh oil in there after the test, the only source is from the turbo.

There are other sources for burning oil, though. If your turbo turns out to be okay, it could be a number of other things. A compression test is the first test of worn rings/leaking valve seals. If you see low numbers, a leakdown test will zero in on what's worn. Post back your results.