Oil Pressure sending unit for 308

Having done a bit of testing on those, I can tell you that they are 18mmx1.5mm. As this is a standard thread, I got a nut, welded an air fitting to it, and with the aid of a regulator on the air line, I could test the pressure of both the sending unit (out of the filter housing of course), and the dash gauge by simply grounding the sender, dialing the pressure in with the key on but not running the motor, and that tells the story as far as both are concerned.
HTH
Kermit

 

A few years back when I was looking for an oil pressure sender replacement I found a few web pages with Veglia (or as some phrased it: "Vage-liar") resistance values. Pantera, Lotus Esprit and Italia used similar gauges. All seemed to be plauged with the same inaccuracies that we experience.

Being the smart person that I am, I saved the addresses to my favorites files but, of course, most are dead links now. Here are what is still good.

http://www.olympus.net/personal/markh/tips.htm

http://www.intermeccanica.org/publications/iocnews/nl21/Newsletter21.htm
ITALIA OIL SENDER REPLACEMENT: by Ed Janis is about half way down the page.

also I copied this from somewhere on the net.

"FERRARI INSTRUMENTS
. To recalibrate the oil and fuel sending units, use a radio shack 10k potentiometer from
the sending unit wire to ground. Adjust for zero psi oil pressure with the ignition on and
the engine not running. Remove and measure the pot and install a 1 watt fixed resistor of
the measured value-approx 2k ohm-in the same position. Fuel units require that you know
the tank level and full seems to be the best place to start. If both gages read low check the
ground connection; it's double nuted at the rear right AC. assy. mount. "

 

I have a related question, today for the first time my temp gauge in my 75 gt4 started acting weird, it was not dead but moving around, hanging out near the low end of the gauge then swinging around. I had been working on my steering wheel earlier and thought that I had somehow caused technician induced faiure as my friend Mike F. calls it. However I only messed with the stalk assembly and even though i tugged on the harness a little everything else works, and when you turn the power off the gauge goes to zero, so it is getting some kind of power. Is there some simple test a non-electrical guy can do to check the water temp sender. I checked the wire and it is firmly attached and have never had a problem with it in the past...???

 

I'll get back to you on the exact sizes...I'm on the road...just put in a new sending unit in my '78 308 US model. My car's original sender HAD the step-up fitting in it. The first sender the shop received was too large to thread into the step-up coupler, yet too small for the oil filter housing's M18x1.5 hole; this most common sender would have required me to change the oil filter housing to accept it. The original size (small dia. thread post) sender is NLA, but the odd-ball M18 sender is available, TWICE the $$$ though. My experience shows THREE different sized oil pressure senders for the 308. When I get home I'll post the differences. PeterB.

 

Oil Sender $53.21 Purchased 3-12-04 at Dennis McCann

My 78 GTS had the reducer as well. The new unit went right in with out the adapter. Dennis showed only one unit for this application.

Cheap if you ask me...

 

You're right...the three sizes I was referring to covered all 308's. The old unit requiring the adaptor is NLA. Dennis gave you an excellent price!