Date:         Mon, 17 Jul 1995 12:48:45 -0400 (EDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Gary Clayton <coyote@nando.net>
Subject:      Problem w/temp gauge

 
I recently put a GEX engine in my '76 Camper -  2L FI, solid lifters.

Last weekend I turned 1000 miles, so: changed oil, adjusted valves, and 
torqed heads.

This weekend I decided to install the new gauges.  The oil pressure was 
an easy decision - replaces the stock sensor.  For oil temp, I found 3 
choices: 1)replace oil dipstick 2)replace oil drain plug 3) use T-fitting 
at oil pressure sensor.  I chose #3.

First I ran wires from the engine compartment to the dash, then mounted 
the gauges.

When I went to install the T-fitting with temp sensor in the side and 
dual-pole pressure sensor in top, I quickly realized it wouldn't fit.  
There is engine tin about 1 1/2 inches above the stock pressure sensor 
with a rubber booty in it.  I went to the hardware store and bought a 6 
inch nipple.  This got everything up where it had clearance, but will 
make getting the distributor cap off a little harder.

The oil pressure gauge seems to be working.  From cold start, the 
pressure goes to about 40psi, then levels at 25-30 after 5 min.
When I come to a stoplight, or am sitting idling, the guage reading drops 
to 5-10psi and the dummy light comes on.  I believe this is due to the 6 
inch nipple I had to use - at idle the oil is not getting up there !?
If I tap the accel. the gauge goes back up. 

The oil temp gauge never moves!  I tested it by unscrewing it from the 
T-fitting (leaving the gauge wire attached and wrapping a bare wire 
around the threads connected to ground).  I boiled water and hurried out 
and dipped the sensor in the bowl.  The gauge went to 180 - seems OK, it 
had to cool a little on my walk from kitchen to garage.  So the only 
thing I can figure is the oil is not getting up the 6 inch nipple to the 
sensor to heat it.  I drove 40 min. and still no reading.  Now I'm 
wondering what happens to the air in the nipple?  If there is an air 
pocket, the pressure gauge might still work - air can press a diaphram as 
easy as oil can - but the temp gauge would not - the air would never get 
as hot as the oil.

Now I guess I will buy a different sensor - one that mounts in the oil 
drain plug would ensure that the sensor was getting contact with oil.

Any comments on my theory?

-gary

coyote@nando.net   Gary Clayton   '76 Campmobile   "Rocinante"