Since noise happens on the highway, and there was engine work done,
echoing other replies, I'd look at pressure switch wire at switch,
connector inbetween, or switch itself first.

There's info in the archives (and notes about which bar the high
pressure switch is. I never bothered to remember. You'll see diagram
showing 1.8 and 0.9 bar for high pressure switch.... wait....
<searches> .... looking at BD looks like it should be a 0.9 bar:
http://busdepot.com/view.jsp?model=43&category=13&group=84&prodgroup=652),
but check out P97.126 Bentley. It shows the switch open. The logic of
that switch is opposite to the low pressure switch. Engine running,
high pressure switch closes. If oil pressure drops below spec of
switch, **above 2K RPM**, switch opens. Bentley shows an image of the
connector on P. 17.10

I'd suggest something thicker with more staying power than WD40 for
speedo cable.

Likely it's a loose wire at switch or faulty switch. If it's not
electrical, get the oil pressure tested.

Neil.

On Wed, Mar 30, 2011 at 9:12 AM, Robert Stewart <robertmstewart@mac.com> wrote:

> The van is an 88 with a newly rebuilt engine with all new sensors.

>
> The sound is only heard on the highway and never at idle.
>
> Before the engine was rebuilt I had a blown head gasket and bad water pump. During that time period before the rebuild the oil pressure warning light went off once while going up a very steep hill and it does not sound like what I remembered at all.
>
> Since the Van's new engine it's been fine which was a year ago. This just started happening in the last 2 months.

> If it is a the oil pressure warning buzzer what should I do?
>
> Here's the check list so far:
> - Clean all the grounds?
> - Replace a relay? If so which one? Location on an 88?
> - I checked the speedo and clip is in place. I even sprayed some silicone WD40 down the cable to be sure it was lubed. No change.
> - ( which sensor location is this? on an 88?) john C wrote: Check the Double connector in the Eng. bay. & �add some electrical grease. To fix a bad connection.
>

-- 
Neil Nicholson '81 VanaJetta 2.0 "Jaco"

http://tubaneil.googlepages.com/

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines