Re: High oil pressure

From: Bob Tom (tigers@bserv.com)
Date: Wed Aug 01 2001 - 16:26:35 EDT


At 03:03 PM 8/1/01 -0400, you wrote:
>Well I just installed an Auto Meter mechanical oil pressure gauge a couple
>of days ago to help keep an eye on the 360 that was installed a couple of
>weeks ago. The motor has about 1100 miles and I'm running 5 w 30 dino oil on
>it now and the oil pressure has me a little concerned. The stock gauge has
>always been erratic so I didn't trust it, but when I installed the Auto
>Meter it shows 70 PSI at idle and as much as 78 PSI when accelerating
>normally when cold, after it warms up it's at 15PSI at idle and 40-50
>PSI(depending on what speed) on the freeway, and up to 60-65 under WOT. I
>don't have a problem with the readings after it's warmed up, but the 70-78
>PSI when cold seems to me to be a little high, especially as the outside
>temps are in the 80-90's, what the hell is going to happen when it's cold
>out. I can't think of anything other than the oil pump causing this, isn't
>there some sort of check valve in the pump. Any idea's or suggestions would
>be appreciated. Thanks Sam South

I don't think that you're cold start oil pressure is too high, especially for
a freshly rebuilt one.

Generally the only "problem" high oil pressure will have is higher oil
temperature
and the oil filter gasket leaking (you'll have to get a lot higher to
explode the oil filter).
It could also cause the oil filter by-pass to open when the engine is cold.
This would
let unfiltered oil go through the engine (but this happens anyways from
time to time).

There is an oil pressure relief spring on the oil pump which can be
adjusted by adding
or removing shims. Removing shims decreases pressure.

I would just see if there are oil spots appearing on the driveway or road
after a period
of parking, or, from time to time, take a look and see if any oil is
leaking from the
gasket along the side the oil filter.

Bob



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