Oil level problem. Please Help
 

My oil level gauge (OLG) is death. Needle stays at O all the time. The engine oil level is OK according to the dipstick. Fuel level gauge woks fine.

I removed and cleaned the oil level sending unit. I also tested it once out using a multimeter. The ohms readings went from 33.5 to around 190.5. Nothing wrong between the empty and full position.

I also checked the signal wire (wht/grn) for continuity between the dashboard and the end at the oil tank.

I checked the voltage at the gauge power supply (red/black). 12 volts.

I don´t know what else to check.

Can you please help me?

Thanks

Miguel

I forgot to mention that the gasket is not made of cork. It is made of some king of rubber very thing. Gasket is so thin that the oil level sending unit face plate might contact the metal oil tank surface.

Do you guys thin that this fact might be the cause of the gauge malfunction? Not really sure if this might change the resistance reading signal that goes to the gauge.

Very frustating.

Thanks again.

Miguel Garcia

Porsche 911 Carrera 1985

remove the wire from the sender then ground it. if the needle works, its you sending unit, if not then its up stream from it.

yes, it has to be cork gasket .The rubber is for fuel sending unit at the tank It is too thin and the oil level sending unit is grounded..

Ivan

Ivan,
What are you talking about??? Yes it should be a cork gasket, but NO WAY,NO HOW, is it "grounding out". If that theory held ANY WATER, then it would "ground out" through the stud, nut, washer, interface.
Boy some people just want to boost there post #'s.
Sorry moderator!

If the signal wire to the gauge is grounded, the gauge should read zero. If you disconnect the signal wire from the gauge, it should peg. If this works at the gauge, try it at the sender. Result should be the same. That leaves only the sender. You have seen how simple it is - a resistance winding with a sliding connection. If the resistance wire wears through, you get funny readings. However, your tests show the gauge is, at least on a gross scale, working - it is creating a varying resistance. I can see why you are baffled, having checked out all of the three possibilities, but it has to be in one of these areas. It certainly has nothing to do with the gasket, which is just there to keep oil from leaking out as it sloshes around in the tank.

..............must have been tired......Thanx Walt & Marc...
Perhaps switched wires on level unit ...

Ivan

Ivan,
Thanks for not getting upset with me, sometimes I don't have the best bedside manners.
Cheers,
Marc

Hi Marc..you know, i did talked to some person in Europe last night with similar(oil level) problem and during the talk i have written this rubbish;-)..all good no big deal;-)

Ivan

Ivan

I fed the +12 and ground connector of the gauge with a 9 volts battery and the needle went all the way up. So my gauge is not death.

One silly question. There was not any ground wire connected to the oil level gauge. The ground connector is there with nothing connected. On the other hand, the fuel level gauge has a brown wire connected.

There is two screws holding both gauges at the same time to the metal housing. Can I assume that the ground wire connected to the fuel level gauge is also grounding the oil level gauge? Shall I install a ground cable for the oil level gauge?

Thanks

So ,you have only one wire coming the the oil tank?There should one little connector unter the mounting nut..take picture what do you have..it should look like this..also take a picture of the back of the gauge from the back..
https://cdn4.pelicanparts.com/techarticles/101_Projects_Porsche_911/19-Oil_Level_Sender/images_med/Pic2.JPG

something like this
https://rennlist.com/forums/attachments/911-forum/616853d1331938110-oil-level-gauge-pegged-now-fixed-gauge-1.jpg

No. I have those two cables connected to the oil level sender. I´m talking about the wiring at the dashboard gauge. There are only two wires connected to the oil level gauge, power wire (+12, black/red) and the signal wire (green/white). No wire connected to the third connector which is labeled as ground. The pic you just sent shows the same ground connector without any ground wire.

The gauge should have part of it ground connector as on picture above,do you have it there.
Ok got it those 2 wires on sending unit are not switched?probably you have tried that right?

Ivan

The read/black wire is +12 volt and it is connected to the right connector. I also checked the signal cable. White/green cable, which is the same that goes to the center of the oil level sending unit.

and the gauge has one brown ground wire attached? as on the pic above

Ivan

Yes, but connected to the fuel level gauge ground connector. Exactly the same layout. My oil level gauge has an unused ground spade connector, exactly like yours.

that is normal one serves both...so the recap is you put the key on and your oil level gauge is not moving at all and stays zero,correct.
Did you take the wire in center of the oil level and touch the ground with it?

Ivan

Oil level reading is 0 all the time. I did not try connecting the signal wire to the ground wire. I´ll do it tomorrow morning. It is almost 23:00 in Spain.

I´ll keep you inform of the results of the test.

Thank you very much for your help.

good night, i have the same time as you since i`m in Czech Republic alias Bohemia;-)

Ivan