1999-2009 [Subscribe to Daily Digest] |
 | [Main 95 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: Help - White Smoke (hoping for the best - Ha Ha) Posted by Larry West [Email]  (#1140)  [Profile/Gallery]
(more from Larry West) on Tue, 11 Dec 2012 07:51:27
In Reply to: Re: Help - White Smoke (hoping for the best - Ha Ha), tsenraem, Mon, 10 Dec 2012 12:54:34 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Were it my car, I would proceed with changing the turbo out, since it is probably better than 3 to 1 odds that is the problem. I'd just be sure I could return the unused replacement turbo if it turned out not to be that.
Worst case, I'd find no oil leaking from the turbo, the shaft spinning freely and with the right amount of play(*), and I'm partway to inspecting and removing the front head to see if the valve seals are leaking...
(*)My personal experience with C900 & 9000 turbos and shaft play is this: the shaft should spin freely. You probably couldn't blow on it and get it to move (surface tension from the oil in the bearings), but two fingers should get the shaft to spin freely, and it should stay spinning at least a bit until the oil surface tension takes over again. ANY friction or grinding, or interruption in the free spinning is a sign of a bad turbo.
I have always found a very slight bit of movement of the shaft. None you could measure, but putting pressure on the shaft radially should get you a definite sensation in your fingers when the shaft bottoms in the bearing housing. Same thing for axial play. If you can see it move, it is too much, and if you feel it moving, rather than just bottoming, it is also likely too much. It's a subtle difference between bad and good...
Most turbos, and most - AFAIK - that Saab installed are plain bearings (e.g. a shaft through an ever so slightly larger hole with oil supplied through the housing), not ball bearings, which should exhibit no play at all.
As for the damage you could do, aside from the oil coating your catalyst and other issues already mentioned, you run the risk of the turbo wheels hitting the housing if the oil can't keep the shaft suspended properly, or if the shaft or housing wears. If you are replacing the whole unit, this isn't a problem, but if you are attempting a rebuild or a cartridge (center section plus shaft & wheels), you can mar the housings such that they are unusable, or at the very least need refinishing to remove excess metal. If they are grooved, they are toast, as the wheel needs to spin very, very closely to the surface of the housing in order for it to work.
_______________________________________ Current: 2002 9-5 Aero Kombi Cosmic Blue 2000 9-5 SE sedan, Imola Red 1990 900S Rose Quartz, Auto Past: 1999 9-5 LPT Combi 1999 9-5 LPT sedan 2002 9-5 Arc 1990 900 5-speed 1986 900 turbo Convertible 1991 9000 turbo 1980 99 GLi 1986 900 turbo 1986 900 S 1991 900 turbo 1984 900 turbo 1976 99 GL
, Mon, 10 Dec 2012 18:38:24, Mon, 10 Dec 2012 10:21:44, Tue, 11 Dec 2012 07:51:27 <-- Viewing This Message
, Mon, 10 Dec 2012 10:26:41, Mon, 10 Dec 2012 12:08:25, Mon, 10 Dec 2012 10:04:07
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
