Low Oil Prssure on New Engine Rebuild

[ricematthews]

Alan:

The good thing is that you probably can to do bearings without full removal
& disassembly of the engine.  Did you "plastigage" the bearings while you
were assembling the engine?

I'm optimistic for you that it's either the gauge/sending unit or that it is
related to the 30 wt oil.  I have used straight 30 as initial break in oil
too and it is very thin when you go to drain it.  This seems especially
likely considering you show 5 bar on a cold engine.  Also, 3 bar at 1750 rpm
on a hot engine doesn't seem bad.

-Mark


>
> James,
>
> Thanks for the reply.  Good point on #1, I don't know for sure (with
> instrumentation besides the stock VDO stuff) that the pressure is 0.5
> bar...but FWIW, I do know that with that sender and gauge that the oil
> pressure is lower on this engine than others.
>
> All the parts I used were 7A, pump, baffle, oil cooler, etc...   They all
> played nicely together on the engine before the rebuild.
>
> Your conclusion in your last sentence was unfortunately mine as well...  I
> was just hoping for something more optomistic :)
>
> Thanks,
> Alan
>
>
>
> >From: "James Bell" <doublem at srv.net>
> >To: "Alan Kramer" <ackramer at hotmail.com>
> >Subject: Re: Low Oil Prssure on New Engine Rebuild
> >Date: Sat, 21 Sep 2002 22:42:05 -0600
> >
> >Alan:
> >
> >First, Use a Borden tube gauge. Instrumentation
> >is first. Do you know, for sure, the oil pressure.
> >
> >Second: what oil system parts did you use. are they
> >all compatible? Cooler, Lines, Temp control manifold,
> >filter, oil pick up and baffle.
> >
> >Rings are not going to cause low oil pressure. Bearings
> >and oil gallery faults will.
> >
> >J.B. in ID.
> >
> >----- Original Message -----
> >From: "Alan Kramer" <ackramer at hotmail.com>
> >To: <quattro at audifans.com>
> >Sent: Saturday, September 21, 2002 8:56 PM
> >Subject: Low Oil Prssure on New Engine Rebuild
> >
> >
> > > Today I started my freshly rebuilt turbocharged 7A (yes 7A, not 3B or
> >AAN)
> > > 20v engine in my CGT.  Started immediatley on the first crank :), but
I
> > > watched as the engine approached operating temperature the oil
pressure
> > > steadily dropped from 5 bar (cold) to 0.5 bar at hot idle.   Oil
> >Pressure
> > > increases to 3 bar at 1750 RPM.  I'm running non-detergent straight 30
> > > weight oil for break in.   I know my rings aren't seated yet, I'm
> >definitely
> > > burning some oil.
> > >
> > > My question is, should I be expecting such a low oil pressure on a
fresh
> > > engine?  Perhaps due to the oil I've chosen for break in? Or am I
likely
> > > looking at some other problem?  I've also verified the sender is
> >correct,
> >I
> > > swapped it with the one in my 4kq and got the same reading.  Last
engine
> >I
> > > built that required breaking in had more "normal" idle oil pressure,
but
> >I
> > > think I might've used a heavier viscosity break in oil.
> > >
> > > Thoughts & comments are greatly appreciated,
> > > Alan
> > >
> > > '83 CGT 20vt
> > > '90 v8q
> > > '86 4kcsq
> > >
> > > http://www.geocities.com/audikramer
> > >
> > >