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staticsan · Joined: 19 Jan 2009 Posts: 450 Location: Sydney, Australia

I've got a bit of a puzzle. For a little while some months ago, my oil pressure was showing at 0 - but the low pressure warning light was never on. With the help of a relative, we tested the gauge and it is working just fine. So I suspected the sender. I just couldn't arrange to replace it.

I don't know how long it was low, but not long afterwards, something changed and now the gauge is pinned. Again I suspected the sender, thinking the armature inside was sticking.

But now I see less than 10bar when starting, and sometimes it does fall to 8 whilst driving. Most of the time, though, the gauge is pinned hard.

What should I be doing? Is there a problem with the oil feeder tube? The oil has no bubbles in it, and is only slightly discoloured - last oil change was about 4,000 miles ago and it was 20W-60 mineral oil.

Wade.
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'82 British NA - Which I think I've been very lucky with!

emoore924 · Joined: 13 Apr 2004 Posts: 2822

IIRC thats what the gauge does when it or the sender is grounded. Check for a short to ground.

Paul · Posted: Mon Sep 24, 2012 12:28 am Post subject:

The oil pressure sender controls both the low pressure light and the gauge, so the fact the low pressure light never comes on is a problem. It should always light when the ignition is turned on.
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

staticsan · Joined: 19 Jan 2009 Posts: 450 Location: Sydney, Australia

pmcaya2 · Joined: 24 Nov 2005 Posts: 191 Location: Scio, NY USA

I had the same problem - the gauge pegged at maximum pressure while the oil light worked normally when key was turned to aux. The problem was a short to the sensor connecting wire. The connection is in a god-awful place near the fire wall. (the engine was designed as a transverse engine for front wheel drive cars, hence the bad location for the sensor).

Anyway, I suspect that the gauge and sensor are fine. I bought a new wire with a connector attached and spliced it to the old wire for a bit more wire to work with. One tool I found useful for the "operation" was a surgical clamp that I happened to have - it allowed me to clamp the wire and hold it in a tight spot. Hope that this helps. - Peter