"Your de Tomaso Connection"
Oil Pressure Gauge
When I found my Pantera in 1998 it had VDO instruments installed in the center console, e.g. 60 amp amp meter, fuel gauge, 250 degree temperature gauge, 80 pound oil pressure gauge. The oil pressure gauge has always acted a little flaky, operating mostly pegged at 80 pounds and then sometimes when the engine was real warm it would jump down to 30 pounds at idle. There was no linear action, it was at 80 pounds at speed, stuck at 80 or sometimes at 30 at idle. The gauge would go to 0 when the key was turned on with the engine off, so I assumed the sender was most likely bad.
Unlike the Cleveland in the Mustang, the oil pressure sender on the Pantera is on the back of the engine just behind the intake manifold. This location is good because it shows the oil pressure at the furthest distance from the oil pump and after the oil has bled through the majority of the rotating engine parts.
The nice thing about VDO instruments is there are a lot of sources for them. I found the best price on the sender, part number 918-360003, at Jegs. http://www.jegs.com
The original sender was equipped with a 1/4 NPT fitting that screwed directly into the engine block. The only 0 – 80 pound VDO sender I could find had a 1/8 NPT-27 fitting so I used an adapter fitting from the local ACE hardware store.
The sender uses the engine block for the ground path so it is important not to use Teflon tape or sealer on the sender or adapter threads.
The new sender fixed the gauge problem and it’s nice to finally know what my oil pressure is. The following two images show the pressure at idle and at 1700 PPM with the water temp a little over 190 degrees. With the engine at full operating temp on a hot Atlanta day the pressure is a shade under 30 pounds with a 750 RPM idle and near 80 pounds at any RPM over 1700. On cold start up idle it is at 80 pounds.