Date: Wed, 1 Jan 2014 19:29:39 -0500
Reply-To: Steve Cotsford <cotsford@AOL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steve Cotsford <cotsford@AOL.COM>
Subject: Re: oil light question
In-Reply-To: <52c4571e.9019e00a.4d72.ffffe046@mx.google.com>
Content-Type: text/plain; charset=us-ascii
Well, following my leaking oil pressure switch, I decided to take them both out and inspect them. The black one, that started leaking today is of VW origin and is marked 0.15 bar to 0.45 bar. The grey one which seems in much better condition, is also of VW origin (Made in Germany) and is marked 0,75 bar to 1.05 bar.
Obviously i will replace the black one, Perhaps I will adapt the old one for a mechanical pressure gauge. The Grey one I am inclined to keep but I will buy a replacement anyway seeing as I had to fight to get it out. There is also a threaded adaptor bushing ( M16 I would say) which came out with this switch which I will clean up and replace with the new switch.
The grey one was very clean, including the wire and connector. The black one was very oily and I have no idea how long it had been like that.
Steve
On Jan 1, 2014, at 12:57 PM, David Beierl <dbeierl@ATTGLOBAL.NET> wrote:
> At 12:04 PM 1/1/2014, Steve Cotsford wrote:
>> So far I have not heard a buzzer sound. I may have to check. The
>> buzzer may be absent .
>
> The blinking light indicates that the circuit board is present, not
> likely that the buzzer is missing.
>
>> If the red light is off at 2500 rpm and does not come back on
>> when the engine idles back down, does this signify that oil
>> pressure is adequate? Thanks Steve
>
> At the moment everything is unknown. If you want to know what your
> oil pressure is, put a gauge on it.
>
> You can check electrically what the senders are doing. Once you've
> idled long enough for the light to start blinking, unplug the
> two-position connector that takes the two O/P senders into the main
> engine harness. Follow the wire from the after sender and you'll find it.
>
> With it unplugged, the side sender should show open circuit to ground
> (more than 100 Kohms, say**). If it doesn't, you either have very
> low pressure or the sender diaphragm is leaking.
>
> The after sender may show open or closed, it's not the issue
> here. At cold idle it should certainly be closed, at hot idle it may
> be open but will close as you rev the engine.
>
> With the engine off, side sender should be grounded and after sender
> should be open.
>
> With the senders unplugged I believe you should see no blink at idle,
> blink and buzzer above 2,000.
>
> **When the sender is closed it should show no more than a few ohms to
> ground. When it's open in theory it should be many megohms. If it's
> failing it may not be actually closed but still have resistance low
> enough to trigger the alarm circuit. I don't know what the
> resistance threshold is for that circuit -- it ought to be less than
> say 100 ohms but VW seem to have a propensity for sensitive circuits
> that might false-trigger on a higher resistance.
>
> Yrs,
> d
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