Low oil pressure reading but oil press OK - now cured

[McBreadhead]

Had car checked over for oil pressure on Friday, sumps swapped (finally) and oil collector plate positioned correctly above sump floor. Achieved 4+ bar at idle when measured mechanically which is bang on but electric gauge (Caterham) showed half this. Any likely causes ie why would gauge only read half actual value?

 

Replaced the sender 2 yrs ago to fix but no joy, gauge still read 2 bar at best. Loathe to go mechanical gauge unless all other possibilities exhausted so do I replace sender (again) or get new Caterham electric gauge? Engine is a recently refreshed xflow, wet sump.

 

Edited by - McBreadhead on 22 May 2011 20:21:52

[Myles]

Where is the gauge mounted? (i.e. the sender, obviously...)

[Stationary M25 Traveller]

Mechanical is The Way Forward

[McBreadhead]

Sender is mounted to large brass nut screwed into the side of the block

[6speedmanual]

Try getting the gauge recalibrated, either by the manufacturer or a gauge repair specialist?

 

Peter

[McBreadhead]

Recalibration? yes that sounds a way forward then.

 

Can't understand why it would suddently read low after I swapped old xflow for this one 4 years ago. I saw this engine had good pressure when in another car so baffled when it dropped in mine.

 

Is it a case of the sender either working or not, or are they sensitive souls that depend on mounting nut or sthg else?

[LazerBrain]

Out of interest, what happens if you take the wire off the sender and touch it to ground? This should normally make the oil gauge go to full scale deflection.

[Golf Juliet Tango]

Mechanical may be nearly essential for a K but not for a Crossflow.

[6speedmanual]

The difficulty with electric/analogue gauges is that they work by teh current flowing through a coil which heats a bi-metallic strip to deflect the needle. Over the life of the gauge, lots of things can change causing it to go out of calibration. It is also notoriously difficult to get good accuracy over a wide range.

 

Still worth a go at getting it set up. Best bet for a recal is to go for reasonable accuracy at the "Normal" reading. Every other reading is an indication of either higher than normal or lower than normal.

 

P

[Molecular--Bob]

Assuming your gauge is a vdo one is the sender correct? as they are available as both 5 bar and 10 bar, which may account for your missing 50%

[McBreadhead]

Put the sender lead to ground and it did indeed go to full deflection

 

Replaced sender today, started her up and got bang on 4 bar from cold. Shows 3 bar in the cruise, then 2 bar when warm idle. Guess that's it sorted then until the sender craps out again.

 

Thanks for all the suggestions. I cannot tell you how much that is a relief. May even start doing some tours again now.

[jonboylaw]

2 Bar hot idle is good for a crossflow !

 

 

 

Jon