Oil Pressure

[pauljmcnulty]

it goes to full even with the sender disconnected.

I thought they default to 5, hence people advertising cars with "5 bar oil pressure all the time" when it's a dodgy sender or gauge. The same as the heater defaulting to "full on", usually in the middle of Summer.

 

[Buddy]

Well Mike, it is possible to get a duff spare, have you got another?

 

[DavidL]

New sender needed surely?
Duff sender defaults to max and open circuit the same hence your results.
I had a duff sender on my old S and that read max until it was fixed.

 

[Lowtimer]

I am not an expert on this but I also believe that the gauge defaults to full deflection and the sender sends the signal that pulls it down to where it ought to be.

So my guess would be a dodgy sender. Mine did this for a while, and Andy at Promax fixed it with a new sender.

 

[Mike_Pollock]

Thanks, didn't know the default is max

I have a sender that was working off my old 2.5 will have to find it now!

 

[geoffbateman]

Just had to change the sender on mine. Depends on the mode of sender failure. My last one failed 15 months ago and that failed with the gauge reading a solid 5 bar even with the engine not running. Change the sender for an FAE unit and problem solved. 15 months later, suddenly pressure drops to 3 bar and oil light comes on at tickover! Engine sounds OK but check oil pressure with test gauge. 5 bar hot at 1500 rpm, up to 8 bar cold at 2500 rpm. Bought new sender from Rock Auto and fitted it, problem solved. Sender from Rock is a Uro one which looks much better quality and looks more like the OE one that was originally fitted.

 

[chrisjcoe]

OPS are difficult beasts to track down, I've been trying for quite some time as I have exactly the same problem.

 

[Copperman05]

Before buying another check the connection, the oil pressure sender sits under the oil filter on the drivers side and is accessible from underneath. It often gets covered in muc and has exposed connectors so may just require a clean and tweak to get working again.


Edd

 

[steve944]

ORIGINAL: Copperman05

Before buying another check the connection, the oil pressure sender sits under the oil filter on the drivers side and is accessible from underneath. It often gets covered in muc and has exposed connectors so may just require a clean and tweak to get working again.


Edd

thanks Edd,
Tried the connections, took them of cleaned them and reconnected still the same!!

cheers,

 

[pauljmcnulty]

ORIGINAL: chrisjcoe

OPS are difficult beasts to track down, I've been trying for quite some time as I have exactly the same problem.

Type 911 have them listed as in stock, OEM or aftermarket versions.

 

[chrisjcoe]

Thanks Paul, Type 911 is the one site I hadn't tried, and they have 2 types!

 

[pauljmcnulty]

ORIGINAL: chrisjcoe

Thanks Paul, Type 911 is the one site I hadn't tried, and they have 2 types!

Looking at Bert's site he has the OEM one as well, not very clearly listed though, it's the 928 part.

 

[edh]

Is usually a sender issue if it starts when ignition is on (but engine off) I think you can also connect the wires the wrong way round - but if it was working & now isn't, then just replace the sender.

 

[steve944]

ORIGINAL: edh

Is usually a sender issue if it starts when ignition is on (but engine off) I think you can also connect the wires the wrong way round - but if it was working & now isn't, then just replace the sender.

Taking the chance, bought one today from type 911 I'll let you know how it goes!!

thanks guys.

 

[geoffbateman]

99% sender. Had to replace 2 on mine now. Both times they were not OE parts. First one I think I got through Eurocarparts and that lasted about 6 months. The second I got from the US via the net and that was a lot better lasted about 18 months. I think you need to be careful to check the spec when you buy it, particularly the over pressure capability of the sender. The sender is ranged for 0 - 5 bar (full gauge range) and the hot oil pressure spec is about 4.5 bar at about 3000 rpm (I think - long while since I checked), however I bought a test gauge to check my pressure when the first sender failed and found that I got about 3 bar at tick over and 4.5 bar at 3000+ rpm with the oil hot, but when cold the pressure got up to 7.5 to 8 bar if revved above 2500 - 3000 rpm until the engine got up to operating temperature. The oil is a good semi-synthetic 10-40 and I've had no running problems for the 6 years I've had the car so I assume it is OK to be like this. On checking the spec of various senders offered for sale, the cheaper ones do not give an over pressure tolerance whereas the more expensive ones gave an over pressure tolerance up to 10 bar. Naturally, I bought at the lower price point and I think this may have been a false economy as it has failed again, this time at maximum, like yours has. I've checked with the test gauge again and all is fine so I'm leaving it for a while to save up for a better sender. or if anyone out there has bought a good one for sensible money I'd be happy to know.

 

[pauljmcnulty]

if anyone out there has bought a good one for sensible money I'd be happy to know.

c. £30 for an OEM one from a reputable UK supplier doesn't seem unreasonable to me, given that the original is often well over 20 years old!

 

[geoffbateman]

When I last looked a couple of years ago OEM ones were al lot more than that or maybe I was looking in the wrong place. Where's that from please, Paul.

 

[944 man]

Mine was £26 a few months ago.

 

[pauljmcnulty]

Where's that from please, Paul.

See posts 5 and 7 above. []