Installed oil pressure gauge -- sludge problem

[Huw Powell]

> I'm confused by the physics of pressure in the system. The more I
> read the less I can make statements about what's going on, but I'll
> try anyway. I've read since my last post. I'm not sure if there's
> much pressure difference in and out of a clean oil filter. When the
> pressure diff increases due to clogging, the valve in the filter will
> begin to open at some pressure differential. Then I assume the
> differential remains constant and more flow goes through the bypass
> as the filter is even more clogged?

I would like to mention that having the bypass valve open due to 
clogging doesn't sound like "normal" operation to me, more of an 
emergency fail-safe.

> Without knowing the internal channels in the housing it's hard to
> know whether this is upstream or downstream from the filter. If this
> plug does access the channel to the center of the filter (as it looks
> like it might based on its position) then it is upstream (oil leaves
> the filter through the center hole -- I originally mistakenly thought
> the reverse of filter design). Does anyone know whether the stock
> pressure warning light is installed upstream or downstream of the
> filter?

I *think* it is after the filter - the I-5 ones are on the side of the 
block.  So the flow is pan to pickup to pump to filter to oil galleys. 
The pressure is created by the combination of flow forced by the pump 
and the small holes that let the oil finally escape from the galleys.

I hope this helps a tiny bit...

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/