E320 Oil pressure zero!!!

[Don777]

I started my car this morning (W124 E320). It hadn't run for about a week and was quite rough for about 3 secs (like it was running on less cylinders)and then settled down to a smooth quiet idle.
I got in and after a 100 yards I noticed there was no oil pressure at all. There was no oil under where the car was parked and none around the engine block. The oil level was low but not empty.
When the ignition is switched on the needle doesn't budge. My questions:
1] Should the needle move when the ignition is switched on, like a check or something?
2] Could it be something simple like the sender?
3] If it is the sender, is it an average diy job?

Thanks
Don.

 

[television]

You can see if the oil is being pumped around by looking in the filler cap.
the sender just screws into the oil gallery on the block, and is an easy job, if it is faulty. Best way to test is with a multimeter connected up.

Malcolm

 

[clive williams]

I started my car this morning (W124 E320). It hadn't run for about a week and was quite rough for about 3 secs (like it was running on less cylinders)and then settled down to a smooth quiet idle.
I got in and after a 100 yards I noticed there was no oil pressure at all. There was no oil under where the car was parked and none around the engine block. The oil level was low but not empty.
When the ignition is switched on the needle doesn't budge. My questions:
1] Should the needle move when the ignition is switched on, like a check or something?
2] Could it be something simple like the sender?
3] If it is the sender, is it an average diy job?

Thanks
Don.

Don, as you've got a smooth quiet idle then I doubt if its oil pressure loss. If it was the whole thing would sound like a bag of nails! and you would be already in for a rebuild. The first place I would look is the sender, then the gauge.

Clive

500E
E320CDIT210

 

[Don777]

Thanks. Whereabouts is the oil sender? near the filter??
Can I remove it to test while the engine is running?

 

[clive williams]

Thanks. Whereabouts is the oil sender? near the filter??
Can I remove it to test while the engine is running?

I'm not sure where the sender unit is on you car but its usually around the oil filter position or screwed into the block oil gallery.

I presume you don't mean to remove the whole sender unit whilst its running - it could get very messy after which you wouldn't have any oil pressure for definite! The electrical connection can be removed so that you can test the resistance of the sender with/without the engine running. The resistance will vary depending on the pressure in the line.

Clive

500E
E320CDIT210

 

[Don777]

I presume you don't mean to remove the whole sender unit whilst its running - it could get very messy after which you wouldn't have any oil pressure for definite!

I'll only remove the electrical connector!

 

[television]

I think you have found the oil sender,on the rear of engine by oil filter. the way you can see if it is the gauge or sender is, if there is only one cable on it, take the wire off and short it to ground, if you then turn on the ignition the gauge should be reading somwhere near max oil presure. If the gauge is not reading anything then the fault is the gauge or wiring. Make sure that the sender lead is shorted to ground (chassis).


If there are two wires please come back.

Malcolm

 

[Don777]

I'll report back as soon as I get back home to the car. Thanks.

 

[Don777]

Right, I've had a look but cant' obviously see the sensor. Is it easy to get at from the top of the engine or will I have to jack it up and come in from underneath? Does anyone have a photo of what I'm looking for by any chance?
Thanks again
Don.

 

[television]

it should be just behind the oil filter at back of engine, also in line with the base of filter, its round with a wire (spade) coming out of the end, a bit smaller than a sparking plug. you do not need to go underneath.

Malcolm

 

[Don777]

I've tried getting at it all morning but there is no way I can get to it! I've tried jacking the car up and getting at it from underneath but that's no good either
I can barely even see it...I'll try and post a photo and perhaps someone could confirm that I'm actually looking at the right thing

 

[television]

Its on the back of filter housing go to this site.

http://www.detali.ru/cat/oem_mb0.asp?TP=1

Look up your car, then engine, oil filter, its item 134.

Malcolm

 

[Don777]

Malcolm,
I managed to find a picture of it before I read your post, and I got my other half to stick her arm in and wiggle the wire. And it's fixed!! Well so far, the whole sensor was loose she said (she could turn it very easily in her hand). Is that normal? Huge relief it wasn't something major.

Thanks for that link, it's great...saves having to get the parts catalog.

 

[television]

Pleased you found it, there should not be anthing loose on it. The chances are that insulator has broken away from the base. I believe it is screwed into the oil filter base, rather than the block. If this is the case you will have to remove the filter base. In doing this you will require a gaskit for the base.


Malcolm

 

[Don777]

Thanks again Malcolm.