International Lancia Forums

My S2 1600 engine was completly rebuilt and I recall when I first started, cold oil pressure was over halfway. When I took the car on its first test run last weekend, pressure was very low (just above minimum) and not really reacting to higher RPM. Have not done another cold start yet but thought I would check the pressure relief valve first. I assume it can be stuck in the open position so that pressure does not build? How do I know it is stuck open? I checked the parts book against my oil filter base and it seems to have more parts than I have on the car! I noticed item 14 is incated as discontinued - i made the corrections as shown on the page attached (Item 6 on my car seems to contain item 5,8,15?). Note part 9 is also missing the "stalk" - it only has the threaded part to screw on the filter. Hope someone can help me out here!

The series 1 relief valve consists of many parts.
The part you show is the series 2 relief valve. This one is known to very very occasionally not close. On the picture it is closed and looks properly cleaned. I doubt that valve caused the problem but it is not 100% ruled out. If you can find a series 1 valve I would replace the S2 valve.

Much more likely is a bad contact inside the pressure sender. Originally the range of the sender was 0 - 6 bar. The ranged is stamped at the bottom. They are no longer available new. Replacements are 0 - 8 bar. I always repair the 6 bar ones.

You can test the sender with compressed air, a pressure regulator and a manometer. At full range (either 6 or 8 bar) the resistance should be 0 Ohm. At 0 bar the resistance should be 300 Ohm. The change as a function of pressure is linear.

The wiring and instrument inside is easy to test. Pull the wire from the sender and hold the contact against a metal part of the engine. The needle should jump to full scale.

As always, thanks for your help Huib. The sender unit is a new one so should function correctly. WIll test it. And if OK, I will check with a proper oil pressure tester. I recall on my beta montecarlo, I had the dash instrument calibrated to the sender unit.

Sounds like the right approach.

If it is a new sender, it is most likely an 8 bar unit. The dash instrument will never go to full scale as the pressure relief valve opens at 6 bar. If you managed to buy a new 6 bar unit let me please know where.