911blackbeauty

996 '04 C4S Cab - electronic oil level in dash shows full all the time i.e. when ignition lights are on and even when oil is drained. Pressure gauge (sensor) works fine. Questions:
1. Any suggestions on what the fault might be?
2. Thinking of replacing oil level sender part no. 996 606 150 00.
3. Where is the oil level sender actually located in the engine?
Thanks for any assistance.

Macster

The level sensor is a loop of mostly bare wire -- the portion that is supposed to be in the oil -- that is supplied a known voltage for a few seconds. The voltage is measured and the difference between the 2 voltage levels is used to derive the oil level.

It is pretty tough wire (I cut a sensor apart to see how it was put together) -- something like ni-chrome -- but it can break. Not sure if this results in an always empty "reading" or always full "reading".

The wire is held taut inside a narrow plastic tube that itself is immersed in engine oil. The wire is looped around a small plastic hook located at the bottom of the tube. Another failure mode is if this hook should break the wire loop would be loose and move about. In this case the reading would vary but it could possibly read always high/full.

You probably won't know the failure mode until you remove the sensor. Before you do check its electrical connection to the engine wiring harness. A *careful* disconnect followed by an equally careful connect -- be sure the two connectors connect fully to each other -- might have the sensor working again by removing some surface corrosion on the connecting pins/sockets in the connectors.

If not you can always remove the sensor and check it out.

The sensor is located on top of the engine under the intake manifold. Not sure if the manifold has to be removed to get to the sensor. The sensor actually extends down into the oil sump. This means it is quite long relatively speaking and could be tricky to remove. And it means the new one could be tricky to install.

Be very very careful "messing" around in/under there. You can break a fragile plastic hose connector or even cause an aged hose to crack and afterwards the sensor works but the engine has a hard to trouble shoot and fix vacuum leak.

911blackbeauty

thanks Macster, looks like I'm in for a new oil level sender.

Macster

Looked for the oil level sensors pics I took but couldn't find them. But I found the oil level sensor in my office in the box with the old Boxster fuel pump. Took a couple of new pics.

The pics are are of a Boxster oil level sensor but the 996 sensor should be similar. (No guarantees though...)

911blackbeauty

that looks like the one, item 21. do you recall / or have a schematic of where it is exactly under the intake manifold?

AWDGuy

This should help
http://www.pelicanparts.com/techarti...ne_Sensors.htm