Oil Pressure question-

[lip277]

Hey folks-
I noticed the oil pressure gage in my W126 420SEL is pegged all the time (at 3 bar). IT happens even with the car not running but the power on. It just happened recently.

Question....
What are the voltages I should expect out of a working gage...??? I'm going to do some looking at the car and want to know what to expect. Would an open circuit (broken wire or infinite resistance) give the pegged reading or would that give 0 pressure? I figure it's either one of those that would do that (open or closed circuit). I figure I need a new sending unit but want to at least try to verify it before I get one.

Thanks

[dtf]

I had a shorted oil pressure unit and it was pegged all the time in the W124.

[tower]

replace your oil pressure sender. Just did this last summer, same symptoms. Talk to Phil.

[lip277]

Thanks-
That's what I was going to do (repace the sender) but was curious what if it was 0 or 12 volts that would peg the needle.

(Pricey little bugger, that sender.... ~$65)

Oh well-
thanks again

[stevebfl]

Try disconnecting the connector and see if the gauge changes.

[lip277]

Finally got a chance to work on the car.

Yep - It was the sender unit.

Thought some of you might like to know in case it's come up on your car.