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The reason is...
Posted by Street (more from Street) on Mon, 15 Mar 2004 23:32:16
In Reply to: Turbo Cool-Down time?, PGAero
[Profile/Gallery]
, Mon, 15 Mar 2004 16:21:59
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the turbo shaft floats on a thin film of oil so it doesn't just slow down after it's been running at high RPMs like you mentioned. Letting the engine idle before shut down allows the shaft time to slow down. If you just shut it down (esp after high engine RPMs), the shaft will want to continue spinning fast but it can't since there is no oil supply (read: film of oil). In that type of situation the shaft will be spinning on a very fast dissapearing film of oil and will then make metal to metal contact which in turn can spin the bearing. I've seen this type of failure many times as most think because they have a water cooled turbo, they don't have to let it idle before shutdown. Also, I've seen some dealers/garages purposely "gun" the engine and immediately shut the engine down. What's even funnier is that they do it on turbo engines and not the n/a engines. See, the engine doesn't have to be hot. Just the RPMs have to be temporarily high (ie gunning the engine) and then cut the oil supply to shorten the life of a turbo. Hope this makes sense.
posted by 62.194.7...
Posts in this Thread:
- Turbo Cool-Down time?, PGAero
, Mon, 15 Mar 2004 16:21:59- Re: Turbo Cool-Down time?, TML
, Tue, 16 Mar 2004 07:42:49 - Yet one more opinion, Ari
, Tue, 16 Mar 2004 05:26:11 - The reason is..., Street, Mon, 15 Mar 2004 23:32:16 <-- Viewing This Message
- Re: Turbo Cool-Down time?, Willy, Mon, 15 Mar 2004 22:15:17
- Re: Turbo Cool-Down time?, Dick in Falls Church, Mon, 15 Mar 2004 17:58:49
- Re: Turbo Cool-Down time?, StevO, Mon, 15 Mar 2004 17:25:38
- Oil does not cool down your turbo but the water coolant, Daren, Mon, 15 Mar 2004 16:59:28
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