oil pressure light flickering????

[telski789]

hi,my 325i has a little red picture of an oil can flickering on the dash,it gets brighter the hotter it gets so im assuming this is oil pressure? the engine runs fine,and the oil level if anything is over,so what could it be? can i put the oil pump from my 320 engine into the 325? just to try it,or could it be the sensor? where is the pressure sensor? help help help please!!

thanks

Terry

[Brianmoooore]

Oil pressure switch on a six pot is fairly low down on the front right hand side of the engine. It has a single wire going to it, looping down from the direction of the water pump pulley.
Three reasons for the oil light to come on:
1/ Dud oil pressure switch - cheap and easy to replace, but usually fail by leaking rather than false readings.
2/ Intermittent short circuit to earth of the single wire where it passes around the front of the engine. Wouldn't be temperature dependant, and more likely to flicker when changing gear , accelerating hard or braking hard.
3/ Knackered engine and/or oil pump.

Re changing oil pump for 320: I suspect they are the same pump, but not sure. With all the work involved in changing it, it would be worthwhile investing in a new one.
You don't say what mileage is on your engine, but 325 M20 short engines are cheap to buy second hand, ( it's the head that's valuable), so you probably be better off either buying a good second hand engine, and selling your current head, or finding a good bottom end and fitting your head to it.

[telski789]

ive only just put this engine in before christmas! i didnt really want to be changing it already! the engine had 114000 on it,it runs sweet,but im sure its the pump,i dont think the sensor is faulty but ill try an oil pressure gauge on it tomorow anyway,lets hope hey! it started flickering on friday very slightly but today it came on literally on startup,what do's this tell you??? im hoping its the sensor,but he pump seems more likely. and anyway,if i go and get another short motor,whats to say that isnt worse than mine?!! my bad luck with cars just go's on....and on...

[Brianmoooore]

114k is peanuts for a M20 engine - my "best" Touring had more than twice that before a recent engine change - nothing wrong with the bottom end then either.
What ever is failing seems to be failing fast, so that makes it more likely to be the pressure sensor.
Just had an idea.- change the oil filter before you go much further, in case its becoming blocked.

[andyp]

ihad this problem a few months ago on one of my e30s and it was the oil pressure switch,,

[telski789]

when you say oil pressure switch,do you mean the sensor?,or is that somthing different? the pressure sensor is on the same side as the exhaust manifold isnt it??what is the sensor that go's into the sump on the passenger side?? thanks for ya help

Terry

[telski789]

....ive put a new filter on just weeks ago,this may be a silly question,but can i change the oil pressure sensor without dropping the oil?? just checking!!

[Templ8e30]

Yes you can change the sensor without draining the sump, the sensor (switch) is only about Ԛ£7 so is the logical place to start.

The oil pumps are the same on all m20 motors and are about Ԛ£50 from ECP or GSF.

If your going to the trouble of changing the pump you might as well fit a new one.

Cheers,

Iain T

[Brianmoooore]

Sensor in the sump on the left hand side is the oil level sensor. i.e. electronic dipstick.

[telski789]

surely if the engine had bad pressure itd sound like a bag of nails? im pretty sure its the sensor......oh pretty please!! got a new ne coming tomoow,thanks for all ya help,this is the best beema forum,OFFICIAL

Terry

[andyp]

like they have said just unscrew the old one and screw the new one in , no loss of oil and make sure the wire has a nice tight connection when you push it back on

[telski789]

job done! it was just a break in the wire where the water pump pulley had been rubbing against it,all sorted now,thank the lord the engines fine!! thanks for all ya help!

Tel