oil Pressure Sender

[gajh]

Hi All,

Does anyone know if there should be a voltage on the wires of the oil pressure sender, mine is not working but would like to make sure that it is not a broken wire first.

Thanks

 

[sr.944man]

Hiya, Go to http://www.clarks-garage.com/, click Garage Shop manual link at left, scroll down to S for Sensors and Guages, Oil Pressure Guage testing. The sensor is a variable resistor, so there should be a voltage on the wires.

 

[gajh]

Thanks for that Steve

 

[chrisg]

Apologies for the delay in replying. I recently had a fault with my Oil pressure sender (944 T) - the Clarks site does say " unless there's an obvious engine related Oil pressure issue, most problems occur with the oil sender" - or words to that effect. My Oil pressure had dropped ~ 1bar at all temperatures and when very hot at tickover was flashing up the low pressure red light on the dash. Having had the engine rebuilt ~ 5k miles ago I didn't think it would be the main bearings. Anyhow, change of sender and back to 4.5bar cold and 3.5 bar hot at tickover. There are two feeds into the pressure sender - 1 = variable which is the blue and white wire, 2 = low pressure warning feed. If you remove 1. the gauge will go to 5 bar. Hope this helps, Chris

 

[gajh]

Thanks Chris i will take off the wire off and see what happens

 

[gajh]

Hi All, bit of a late reply, the problem was the cable was broken when the oil filter was changed, I replaced the wiring and oil pressure is all ok now. Thanks Gavin

 

[Frenchy]

Got it sorted good stuff, i would have guessed that the sender gives a variable resistance for the gauge, by that i mean the resistance not voltage would have been measured, the low pressure switch would probably be down to earth 0 volts - neg to bring the warning light on ? Maybe wrong but just my 2p

 

[zcacogp]

While on the topic of oil pressure senders, how do you get them off? As in, I know there is a 24mm (I think) nut at the end of the threads, hidden behind the main bulk of the thing, but I can't get a spanner on it and get any swing to loosen it. There is a steering rack, various pipes and an ARB in the way. Is there a good trick? Nifty technique? A particular tool? Anything? The reason I ask is that my sender has a leak, and always has had, and I think it's to do with the copper washer that seals it. But I can't get it off to check! Oli.

 

[Frenchy]

"They all do that sir" yes there is a copper crush washer M18 i think, the crimped body can also leak, they are a sod to tighten, i managed using a couple of different offset 24 mm spanners giving about 2mm movement each time......................a right bugger about ! Tried with the oil filter removed and the PS pump out of the way not that much help really. Got a good one in the garage should you need one £35 posted.

 

[chrisg]

Oili, do you want to borrow my 24mm spanner wot I used for fitting my new oil sender a few months ago..... ? Let me know ASAP as still haven't (but will tomorrow) post belts tools to you ? It is as expressed a right pig of a job but doable. C

 

[edh]

It's much easier if you cut down a spanner so it doesn't foul the arb. I have a "special tool" somewhere for this job. Getting ps pump out of the way can help as well.

 

[zcacogp]

Chaps, Thanks for the answers. James, sounds like your experience mirrors mine - jolly fiddly. Different offset spanners is an interesting idea. I think that my unit is OK and it's the washer that is leaking (at least, that's what I am hoping), but thanks for the offer of the replacement. Chris, thanks for the offer but I've got one. Unless I was to borrow yours and return it a few inches shorter, as Ed suggests ... [] As i said, no rush at all on the belt tools - I haven't looked any further into buying the parts yet so there will be no progress for a while. Ed, thanks. PS pump removal may be the key. Seems like a lot of work to get in to do something enormously trivial. Ho hummm. Oli.