Re: Oil filters and ADV

[Tony Lum <tlum@flash.net>]

At 12:41 PM 10/8/98 GMT, you wrote:
>In message <3.0.3.32.19981008054313.0073a140@pcpros.net> Mark Switek writes:
>
>> My understanding is that the adv in the filter is to keep the filter
>> charged with oil to prevent a dry start up period. Audi runs check vales in
>> the block to keep oil to the cam and lifter area of the engine. Any
comments?
>
>Then your feet would get covered in oil when you lifted the head,
>irrespective of whether you had removed the filter cartridge previously
>or not.  Doesn't seem to happen.
>
>I don't know about the A4, but there are no valves in the MB block.
>
>--
> Phil Payne
> Phone: 0385 302803   Fax: 01536 723021
> (The contents of this post will _NOT_ appear in the UK Newsletter.)
>
Hi Phil,

This is a quote from the 1985 Model Change Information publication by Audi:

"All Audi engines except the Audi Quattro Turbo will come equipped with
hydraulic lifters.  Combined with the lifters is an oil spray jet that was
first used on the 1984 Audi 4 cylinder engine.  This oil spray jet performs
threee functions.  These are:

-Prevent oil from bleeding back from the lifters when the engine is shut off.
-Prevent air from being supplied to the lifters when the engine is first
started.
-Provided additional lubrication to the camshaft and valve lifters.

The spray jet assembly has a restrictor tube which is higher than the oil
supply channel to the valve lifters.  When the engine is shut off, this
restrictor prevents the oil in the supply chnnel from draining back.  Air
will also enter through the oil spray jet and prevent any syphoning of oil
from the valve lifter supply channel as the main channel drains back.

When the engine is first started, any air in the supply channel is bled
through the oil spray jet instead of the being trapped and supplied to the
valve lifters.  The spray jet then supplies additional lubrication to the
camshaft and valve lifters."

HTH,

-Tony
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Tony Lum  (tlum@flash.net)                  1987 5000CS Turbo Quattro
Berkeley, California, USA                    1985 4000CS Quattro
Audi Owner/Driver/Mechanic by Necessity ;^)   1980 5000S Sedan
                                               1987.5 Coupe GT (new)
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