[Biturbos4] S4 Biturbo newbie
gfl1 at optonline.net
Wed Dec 22 20:45:40 EST 2004
Ah, I "assumed" ...
Turbos run hot - really hot. I've seen them glow at night after a
2-hour run on the highway.
So if you run them hard, then immediately turn off the motor, the oil
stops circulating, and a little bit sits there in the turbo bearing and
cooks -either into sludge or into coke (which is a little softer than
diamond and will destroy a bearing pronto).
So, the best advice is: after any hard run, let the engine idle for
60-90 seconds, while the oil circulates through the turbo, cooling it.
Then when you shut down, the remaining oil does not cook.
Please overlook the fact that your [potential] Audi has water cooling
and an after-run pump. yes, they help alleviate this issue. but its
still good advice. not necessary if you're just putting around town.
On Dec 22, 2004, at 9:33 AM, Paul Jones wrote:
> Outstanding info! But I must admit I'm a tad confused about the "cool
> it down before shutting the engine off" bit. What are you supposed to
>> From: Grant <gfl1 at optonline.net>
>> To: Paul Jones <elsey12 at hotmail.com>
>> CC: biturbos4 at www.audifans.com
>> Subject: Re: [Biturbos4] S4 Biturbo newbie
>> Date: Tue, 21 Dec 2004 19:24:25 -0500
>> Mine's been pretty good. Very solid car.
>> The turbos are a costly, fragile part however. For starters, there
>> are two. They need to be replaced in pairs, supposedly. Replacement
>> requires engine removal, so its costly. On the other hand, Audi has
>> equipped it for longevity. The turbos are water-cooled, and there is
>> an after-run pump to keep H2O circulating after you shut it off.
>> There is no maintenance possible per se, btu precautions that apply
>> to ANY turbo car:
>> 1. Easy when its cold
>> 2. Cool it down before shutting the engine off
>> 3. Use synthetic oil, which resists coking at the higher temperatures
>> that exist at the turbo
>> 4. Change it frequently, I do it ~5k with Mobil 1
>> Problem with a used one is "what did the previous owner, who didn;t
>> plan to keep it long anyway, do?". frequently, not much. Audi does
>> NOT pay for synthetic in 6-cyl turbos, so it got regular oil for the
>> first 50k, unless the owner carried a bag of mobil 1 to the dealer
>> twice a year (like I did). Did he cool it down? Warm it up?
>> You'll just have to feel out the owner and hope for the best. Do
>> listen for excessive whining under load ( a bad sign).
>> Other than that, the timing belt service is a bit costly, and should
>> be done at (let the debates begin) ~75k. Figure $900-1500, depending
>> on who does it, with the water pump, thermostat, idler and tensioner
>> all at the same time.
>> Tie rods fail early, as do some control arms. Life goes on.
>> Despite all this, the car has been very solid. Heavy duty
>> throughout. 20mpg "normal", with 25+ on the highway.
>> Oh, yea, tune ups are a bear for the DIY, but do-able. Also, careful
>> of the 17" wheels with 45-series tires. They bend. You can get 16'
>> on for snows, but only a select few 16" will clear the big brakes.
>> Mine now has 73k, no rattles, burns almost no oil, no major repairs
>> save the tie-rods and a couple control arms. And once done, it drove
>> *like new*.
>> On Dec 21, 2004, at 10:21 AM, Paul Jones wrote:
>>> Hi all. I have recently sold my '93 V8 and I am considering buying a
>>> '00 S4. Having had no previous experience with turbo Audi's I am in
>>> need of some basic info. on the cars. What are the major problem
>>> spots? What are the major buyers guidelines? Plus, is there any
>>> special maintainence that must be performed on the turbos
>>> Biturbos4 mailing list
>>> Biturbos4 at www.audifans.com
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