Low Oil Pressure Only On Start Up

[KRISKARRERA 2 1 Cars]

For a few months now I've had an oil pressure problem.

 

When the engine is left overnight, or for a good 10 hours, and you start it up the oil pressure warning light comes on for a couple of seconds.

 

First thought was that the sensor was playing up. Unfortunately there's no way it can be that because when the light is on those few seconds you can actually hear the painful metal against metal contact in the head!

 

When this started a few months back I had a s*ite oil filter on the engine so I guessed it might not have a non-return valve. But now I've fitter and Pug filter and I'm still getting the same sh1t.

 

Really got me stumped this one! Why would the oil drain out of the head?

[Grim.Badger 15]

Have you got any petrol contaminating the oil? This would make it very thin and it could well drain if it was very bad. Can't really see it happening myself but it's a possibility.

Are you certain that oil is getting to the head at all? I suppose it could be a weak pump

 

Edited because I can't spell

Edited July 11, 2006 by Grim.Badger

[Pug_101 0]

Maybe worth checking the pressure spring in the oil pump . If your still using the car put some oil additive in there to help stop excessive wear.

[jim21070 2]

It could even be as simple as having a cheap non-OE oil filter on that allows oil to drain from it back into the sump. IIRC the genuine filter has a rubber flap-valve arrangement to hold oil in the filter between runs. Cheap ones omit this and the orientation of the filter allows oil to drain out very easily.

[KRISKARRERA 2 1 Cars]

It's a genuine filter though. I suppose it could be faulty...