If a VDO gauge I would check the wiring to the sender and engine grounds. Just a little bit of corrosion at the ring terminal or crimp will cause higher pressure readings. This gauge uses reverse logic. Disconnecting the sensor lead will peg the gauge. Grounding it will bring the needle to zero.

Dennis,
From my Windows phone.
________________________________
From: Mark McCulley<mailto:markmcculley@GMAIL.COM>
Sent: �6/�20/�2017 3:24 PM
To: vanagon@GERRY.VANAGON.COM<mailto:vanagon@GERRY.VANAGON.COM>
Subject: Re: high oil pressure

It's measured in the case.

On Tue, Jun 20, 2017 at 12:12 PM, Stuart MacMillan <stuartmacm@gmail.com>
wrote:

> Where are you measuring the oil pressure? In the case or at a bypass
> plate? If bypass plate It's the filter.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Mark McCulley
> Sent: Tuesday, June 20, 2017 9:06 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: high oil pressure
>
> An odd thing happened this past weekend while driving my stock 2.1 on a
> short road trip. I'd been cruising on the highway for about an hour,
> travelling 70-75mph, glanced at my oil pressure gauge and was surprised to
> see it reading 60psi. Normally it would be just below 30. I checked the oil
> temp gauge, it was normal, about 200F. Checked the tach, no, I wasn't in
> 3rd gear. I kept an eye on it, the pressure reading didn't change until I
> got off the freeway, then it dropped with the rpms. The next bit of
> travelling was on a secondary road so didn't get back up to freeway speeds,
> but oil pressure seemed normal for the rest of the way to our destination.
> And on the return trip a couple of days later, driving the same freeway at
> 70-75mph, oil pressure gauge stayed just below the 30psi that I'm
> accustomed to seeing.
>
> Any ideas what could have happened here?
>
> -Mark
> '87 syncro
>
>