Re: oil pressure drop, but oil level fine...

[Gerard <gerard@poboxes.com>]

> It isn't surprising that you're seeing lower idle oil pressures switching
> over to 5w40 synthetic oil.  5w40 refers to the fact that the oil flows like
> a (very light weight) 5w oil at low temperatures and like a 40w oil at high
> temperatures.  Oil pressure is caused in part by the viscosity (resistance to
> flow) of the oil you are using.  Most Audi's call for a 10w -- oil in the
> owner's manual and you are using a lighter lubricant.
> 
> As long as your oil pump is providing enough oil _volume_ to maintain
> sufficient hydrodynamic lubrication of all of the bearing surfaces in your
> engine, the pressure drop at idle shouldn't concern you (as long as it's not
> in the region of 0).  Since you have been driving your car, and it hasn't
> seized or otherwise self-destructed, your oil pump is probably OK.  In the
> meantime, you are enjoying the slight horsepower benefit of the lower pumping
> losses associated with using a lighter weight oil...Chevrolet engineers did
> the same thing when they switched to lower-viscosity lubricants on newer
> Corvettes.  I'd just fix the leaks.

The car is back in the garage for the leak. I've now learnt that the
low pressure is just caused by the low viscocities I'm running in
the motor now. What concerns me is that I don't know what to consider
as a "low oil pressure situation" anymore. When will the oil pressure
light normally light up? At 0 I presume. I guess if the things is
running and running within temperature spec then it should be fine.
As for horsepower increase....yeeehaaa!!! The increase is
pheromonomenal!!! :) The engine is a nice spinner now, revs better
than it used to.

Thanks for the help.

Cheers!

G.
-- 
"a thousand miles from here, there is another person smiling"
name   : gerard van vught
tel    : +27-57-912 2658 (w) / 082 923 9609 (cell)
url    : http://www.acenet.co.za/homepages/gerard/
e-mail : gerard@poboxes.com  / han.solo@galaxycorp.com
         gerard@acenet.co.za / van_vught@frg.issi.co.za