Oil pressure insufficient

[JWalshe]

Hi all,

Getting this warning message and the dreaded oil light. Fine from cold but it flickers as the engine gets warmer, until it lights up fully. Car drives fine. 

I can’t reach the oil pressure switch but it looks to me like there’s only one wire running from the back of the plug that goes into it. See pic. Is that normal?

(It’s a 2003 2-litre HDi).

Thanks loads!

James

[Guanock]

That looks to as if one of the two wires has broken.

Geoff

[oilyrag]

Agree that there appears to be a broken wire spotted by Geoff, but not sure that the symptoms you have match the missing wire - which I would have thought would have given the same reading no matter what the engine temp. However ther may have been a thread of wire that has snapped when the plug was moved for a photo.
Certainly as a starting point it would be worth fixing the wiring and I'd be tempted to fit a new oil pressure switch as it may be the cause - if the problem persists after that then use a heavier grade of oil, and winter temps will also help.  Beyond that it might indicate bearing wear.

[cancunia]

Is that the pressure sensor or the level indicator in the pictures? Either way, it does indeed look like a broken wire.

If the pressure is dropping as the engine gets warmer, as mentioned above it may be engine wear.
How many miles & what spec oil are you using?

[JWalshe]

Is that the pressure sensor or the level indicator in the pictures? Either way, it does indeed look like a broken wire.

If the pressure is dropping as the engine gets warmer, as mentioned above it may be engine wear.
How many miles & what spec oil are you using?

The previous owner had the car serviced recently (it has 80,000 miles) and used the correct grade by the looks of the bill. 

Interestingly, I moved the wire to take the photograph last night and today, the warning light hasn’t returned! I’m going to take a guess that it could have been a bad connection. 

It’s very grubby in the oil pressure switch area, so probably hasn’t been touched since it left the factory. No sign of a replacement in the paperwork. The service history is impeccable - every bill itemised since new as it was Autocar’s former test car (thus serviced by Citroen UK for 19 years).

I’m going to replace the oil pressure switch and splice that wire to make a cleaner connection to the back of the plug. I’ll report back in the coming weeks!

Thanks loads!