oil light

[carnut]

any one solve this one for me, i have an 325i and the oil light stays on at startup and then goes out only after the engine is running at over 2500rpm's as soon as it goes back under 2500 the light comes back on i have changed the oil pressure sensor the oil pump, filter, with new oil can any one help and the engine has been rebuilt after a esapade with a deep puddle resulting in replacement of two of the con rods and every thing else that should go with. help

[slideways]

i'd check the oil pressure with a gauge. oil light goes out after only half a bar (around 7psi). how long has this beeen going on? disconnect the oil light and check if the light stays on. if it does it sounds like you are getting an earth from somewhere in the wiring

[carnut]

aready done that the oil light is ok as it goes out when unpluged from sensor as for the gauge tryed that aswell on tickover looks like there is not a lot of pressure but give it revs it gose up a bit will a thiker grade of oil help.

[slideways]

that won't relly work unless you are gonna off load it onto someone else the day after you put the oil in. real john wayne effort.
was it a new sensor you put in. on tick over you should have enough to put out the light. was engine repaired pro?
gonna reck your cam wit low pressure

[carnut]

got sensor of another 325 that i have, with it going into water will it of blocked any of the oilways in the engine and ifso how do i unblock them,
me and a few mates done the engine not at a bmw garage but we all have a very good knowledge of mechanics, i am not wanting to kill this as the car has around Ԛ£15000 of bills that came with it when it when we got it and want it as good as it was before it went swimming.

[slideways]

blocking an oil way will only increase oil pressure, as presure it made by a reistance to flow. so low oil pressure means, if the oil pump is puttting out enough oil, means you have a leak. this could be by engine wear in big ends or you have a leak somewhere on the main gallery. is the car losing oil into the water jacket, or burning oil (blue smoke)?
Is the oil pump new/the same as the one that came off. has the car done much since the oil light has come on? start the car and remove the oil filler cap. you should be able to see oil splashing onto the cam through the hole

[Martinaston]

I'm not sure how the pressure switch works but could corroded terminals in the wiring cause too high/low resistance from the sender causing the light to stay on too long ?

[carnut]

car hasnt lost any oil no burning or any in the water, so i have come to the conclusion its time to to replace the shells and see if that makes a diferance as these were not done fingers crossed. let you all know what the results are when i get them in. thanks for your help