Date: Wed, 18 Nov 2015 23:54:24 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Oil light and warning
In-Reply-To: <CA+az7_4Hzs-9KDV29KncriVL1xC+yGeK+y8bAvo2UdbEwpqJWw@mail.gmail.com>
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As a test ground the wire to the higher pressure sensor. If the problem goes away you know the that either the sensor is failing or you have a true oil pressure problem. There is nothing overly high tech or complicated with this system and it is not unique to the Vanagon. Since the board never goes bad except for outright abuse or foolishness there was no reason for anyone to make this part available.
What makes diagnosing this situation difficult is the fact that the Waterboxer can be perfectly healthy and under some conditions even with the correct oil get the oil hot enough to cause the pressure to drop and set off this alarm. Waiting for the pressure to drop so low at speed to wait for the lower switch to turn on the light is usually too late. Also, the light may not get noticed, you usually won’t miss that buzzer.
If the warning is intermittent, then most likely the system is working. What is probably happening is that after warm up oil pressure is dropping below the threshold of that switch. If you have the correct switch, (.9 Bar) you need 13psi to close the switch and satisfy the circuit. If your engine can’t reliably reach that pressure above 2,000 rpm you have a problem. It may not mean immediate failure but something is wrong. On high mileage engines especially rebuilds or engines that have overheated the usual cause is the case is shot and bearings are loose. Local rebuilds replacing the bearings only provide temporary relief as the wear was not fixed. There are only a few rebuilders with the equipment to properly repair these cases.
BTW before this response I paid attention to the oil pressure gauge in Fun Bus driving in Florida. Yes I have an oil cooler so at oil temp of 180F I was just breaking over 30 psi at 2,000 rpm. This is on an engine that just turned 285K. On the highway this engine still holds ~45psi. Unfortunately the rear main seal which was replaced when I re-installed the transmission is leaking and making a big mess. Guess the trans is coming out again when I get home.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of John Rodgers
Sent: Wednesday, November 18, 2015 4:30 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Oil light and warning
This light and warning horn fault of coming on around 2200 rpm is still plaguing me. I have spoken with a most highly reputable shop and was advised this is problematic only in the sense that the dynamic system is not working properly, gives erroneous information, and causes near heart attacks.
It COULD indicate loss of oil and pressure, but most often not. It's mainly a big annoyance, but one you definitely want to check out. The oil pressure switches are readily available, but the circuit board that goes in the dash pod is not. It seems to be NLA. This raises a problem on how to deal with this.
GoWesty makes blue ribbon replacement kit, and it addresses this issue, but it's pricey. The other option and the one suggested, and also used by the shop, was to install an oil pressure and temperature guage.
The one thing I still am not sure about, was the recomendation to remove the wire from the high pressure switch by the water pump pully, and groung it to the block or frame.
Any ideas about that?
John
