Low oil pressure 200 20V

[QSHIPQ at aol.com]

FYI this is a common problem, tho the sender sits behind the oil temp switch, so a low reading on the guage makes me discount this argument.  First, don't trust any audi sensor, they suck wind.  If you "think" you have low oil pressure, find out, even audi has calibrated tools at the dealers for this.

Second, audi published a very detailed SAE paper on oil pressure specifically in reference to the I5t.  I have a copy of it, and have posted it and it's results in the main list archives.  Oil pressure in audis is much lower than one thinks, and it's actually volume and pressure drops that's more of an issue.

The low oil pressure switches found in the I5 motors do fail, but when they do, it's failing ON, not failing off.  If you have no indication of low oil pressure from these senders, chances are really good you have no worries.  There are 2 sensors, a .3 bar sensor for startup, and a 1.8bar sensor for 2k+ rpm.  If neither triggrs, I'd dare say you haven't got a problem, and/or ck the accuracy of the guage first.

HTH

Scott Justusson
QSHIPQ Performance Tuning
Chicago
In a message dated 5/5/2003 9:32:21 AM Eastern Standard Time, b.benz at charter.net writes:

> If one isn't very careful one can learn something new every day!  I knew
> that there was a check valve under one of the pressure senders but have not
> been curious enough to investigate why or where in the oiling circuit was.
> Lucky for you that the top end can go for some time with min lube, just a
> few complaints from the lifters.
>
> Bernie
>
> > From: "Michael Hopton" <Michael at siliconoptix.com>
> > Date: Mon, 5 May 2003 10:20:46 -0400
> > To: "Bernie Benz" <b.benz at charter.net>, <SuffolkD at aol.com>
> > Cc: "200q20V mailing list" <200q20v at audifans.com>
> > Subject: RE: Low oil pressure 200 20V
> >
> > When I had the 3B in my car rebuilt I had no oil pressure. In trying
> > to find the cause the pump, oil pan and oil filter were all removed
> > at least twice. We even tried packing the pump with gease in case
> > it was a priming issue. Nothing worked and I was ready to pull
> > the engine and send it back to the engine builder, turns out there
> > is a spring loaded check valve that holds oil in the head after shut off.
> > The valve is located behind the pressure transducers, so you can get
> > oil pressure in the bottom end with it stuck closed but no oil reaches
> > the head. Pulled the valve and it was gummed up, replaced it and oil
> > pressure is fine. It is possible this valve could stick partially open
> > limiting flow to the head/sensors, after a while, heat cycles, clean
> > oil and pressure from the pump it could start working
> normally, just a
> > thought.
> >
> > Cheers, Mike
> >