what fails in oil pressure sender?

[bigchillcar]

mine needs replacing..i guess. part of me wants to remove the part, 'bang on it' and stick it back in and see if it works. what's the principle with it? how does it fail? is this worth a try? after all the darned things cost over $70!
ryan

[randywebb]

my bet is that the metal accordian fails (turns into a tuba or something...)

it is not worth your while... trust me - if you still have that desire to bang on things, you can alleviate it by going to grad. school in one of the hard sciences

[wholberg]

I could not find a picture of a Porsche unit, but most oil pressure sending units have a spring that compresses as oil pressure increases, and the movement inside the unit is translated electronically to gauge movement. Pressure sending units fail when the spring eventually collapses or breaks due to metal fatigue, so when they break, they are broke for good. Just replace it.

[bigchillcar]

mine is sort of intermittent..it's accurate only now after the oil has heated..when cold it just pegs out. still replace or can i beat on it? please..?
ryan

[randywebb]

beat it

[RoninLB]

fwiw.. old hard info is that art classes had more action for banging than the hard sciences.

and senders get beat over time.

[bigchillcar]

ohhh, okay. damn..i really wanted to beat it..
ryan

[ChrisBennet]

The oil pressure gauge will peg when the sender is disconnected right?
Sounds like the potentiomer "wiper" is making intermittent contact with the track inside the sender. Replacethe sender. I've got a cut open one I saved. If someone really wants a picture I'll dig it out and take one.

-Chris

[randywebb]

A pic would be a public benefit, Chris!

Ryan - feel free to beat it - even tho that won't make it work again...

[RoninLB]

the pics may not be an exact bosch design.

[bigchillcar]

thanks for the diagram, ron..sounds like my diaphragm is weak..at start the higher pressure must be expanding it to full resistance and as the temp inceases and pressure decreases, it must start shrinking back and starting to indicate accurately..at least for now until it finally gives. new sender it is..and i promise when i get the old one out I WILL BEAT IT!
ryan

[randywebb]

take the can off w/ a nibbler or Demel cutoff tool or shears

post a pic of the internals

then crush the whole thing with a sledge hammer; toss into recycle bin and have a beer

[ChrisBennet]

Originally posted by bigchillcar
thanks for the diagram, ron..sounds like my diaphragm is weak..at start the higher pressure must be expanding it to full resistance and as the temp inceases and pressure decreases, it must start shrinking back and starting to indicate accurately..at least for now until it finally gives. new sender it is..and i promise when i get the old one out I WILL BEAT IT!
ryan

If the dial is pegging sometimes, I don't think the diaphram is at fault. Pegging the dial is the symptom I usually associate with a disconnected (911) sensor. My theory is that the electrical part of the sender (the potentiomer) is the culprit.
-Chris

[ChrisBennet]

[bigchillcar]

chris,
thanks for the pic! is that beneath the top of the sender where the wire enters? i'm still peggin' when pressure is high as in cool oil..working normally once pressure drops and oil warms. you can predict everytime you drive approximately when the needles going to fall from the top and begin working accurately.
ryan

[ChrisBennet]

Originally posted by bigchillcar
chris,
thanks for the pic! is that beneath the top of the sender where the wire enters? i'm still peggin' when pressure is high as in cool oil..working normally once pressure drops and oil warms. you can predict everytime you drive approximately when the needles going to fall from the top and begin working accurately.
ryan

Yes, that red wire would go to the spade connector on the top of the unit. If you remove the sender (easier said than done) you can "test" it using your air compressor set at different pressures.
I'm as frugal as they get but I don't think you can fix one of these senders.
Of course just saying that is going make you try all the harder isn't it?
-Chris

[bigchillcar]

Of course just saying that is going make you try all the harder isn't it?

boy, it's tempting..lol. no, i think it's time to spend the $70-odd bucks. just the other day i ordered a new turn signal relay..and you know what? as soon as the part shipped, my old relay began working after i found a loose turn signal bulb in its socket..naturally. i just know this baby is waiting to start working as soon as i order a replacement too!
ryan

[randywebb]

no no - don't spend $70! never do that when you can waste months out of your life fiddling with it first...

[bigchillcar]

randallll..do i detect a note of sarcasm..?? hmmmmmmmmmmm?
ryan

[rw7810]

I’m having the exact same issue on my 2.2 liter, any updates?