Date: Tue, 4 Nov 2014 19:45:05 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Warning light
In-Reply-To: <3B8AB869-60C7-4181-93CD-4F684C94BCA7@gmail.com>
Content-Type: text/plain; charset="US-ASCII"
Just be clear which light. The oil pressure warning light is next to that
oil can looking symbol in the center of the cluster. The coolant warning
light is in the coolant temperature gauge.
The oil pressure warning system is a bit complex. There are two sensors. A
.3 bar (~4 psi) normally closed is located between the push rod tubes. There
is a higher pressure switch .9 bar (~13 psi) normally open switch located at
the rear of the engine. The switches use the different logic to provide a
fail-safe. Defeating the .9bar switch will require connecting the signal
wire to a chassis ground.
With key on, engine off, the low pressure switch will be closed causing the
light to blink. The high pressure switch is ignored. When the engine is
started oil pressure will open the low pressure switch and turn the light
off. Sufficient pressure will also close the high pressure switch. Above
~2,000 rpm the dynamic oil pressure control board will check the high
pressure switch. If that switch is open you will get the light and buzzer.
Once latched, it will stay activated until the high pressure switch is
closed or the ignition is cycled.
So your symptoms are indication a problem with the high pressure switch
including even having the wrong one or a marginal oil pressure situation.
Low oil pressure can be caused by a number of factors such as incorrect
viscosity, high oil temperature, worn pump or bearings, clogged oil filter,
oil dilution, etc. A healthy engine should be able to maintain close 10
psi/1,000 rpm. There are times when the Vanagon engine cannot do this but
not being able to maintain 12-13 psi above 2,000 rpm should get your
attention. A common cause for high oil temperature is overfilling. The top
mark on the dipstick is not the "full" mark. It is the "maximum do not ever
exceed no matter what" mark. At oil and filter time 4.5 quarts is all you
need. For the high pressure switch I am finding that much of the
after-market stuff is inconsistent. Go to the dealer and be sure to get the
correct one.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Jowell
Sent: Tuesday, November 04, 2014 3:35 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Warning light
I am trying to understand the warning light on the temperature gauge of my
1988 Westy.
Going off the interstate the light and buzzer goes on for a second. If I
accelerate slightly the light and buzzer goes off. Is this telling me that I
am low in coolant? Coolant temperature is mid range all the time. Or is it
and oil pressure issue? Read my Bentley and owners manual still no
explanation.
Dennis Jowell
Scotch Hollow Farm
Newbury Vermont