Low Oil Pressure Message - BMW Forum

DonJ · 08-31-2009, 08:40 AM

I changed the oil and filter on my 91 535i the other day.

Now I get a message "Low Oil Pressure" on the message display on the dashboard.

The message goes away after after a few seconds and then comes on again when I shut the car off. If I start it up again, the message does not display.

I've checked the oil level and it is fine and it seems to run fine.

Will this message go away after a bit or does it need to be cleared by a mechanic or what?

Thanks!

darkhorse737 · 08-31-2009, 10:17 AM

...and before the oil change no problems???? hmmm... bad filter maybe?

be on the safe side and have the oil pressure checked.

low oil pressure or no pressure will melt your engine reaaaallly fast.

*doesn't need to be cleared by mech... but low oil pressure can be either too much sludge accumulated in engine, oil pump going bad, or oil pressure guage failing(or maybe oil pressure wire at the sensor just loose).

DonJ · 08-31-2009, 10:55 AM

Thanks Darkhorse - I'll get it checked.

I have only had the car for about 3 months, so I don't know when the oil was last changed. But it never gave me that message before.

The oil filter canister is on tight, no leaks around it.

The message does not stay on constantly and the oil pressure idiot light never stays illuminated (it illuminates when the key is on - which is normal - but then the light turns off once the car starts up - as it should). The message comes on when I start it for the first time that day but it does not come back on when it is started again later on the same day.

The exact message is "Low Oil Pressure - Check Owners Manual".

darkhorse737 · 08-31-2009, 11:00 AM

Quote:

Originally Posted by DonJ

Thanks Darkhorse - I'll get it checked.

I have only had the car for about 3 months, so I don't know when the oil was last changed. But it never gave me that message before.

The oil filter canister is on tight, no leaks around it.

The message does not stay on constantly and the oil pressure idiot light never stays illuminated (it illuminates when the key is on - which is normal - but then the light turns off once the car starts up - as it should). The message comes on when I start it for the first time that day but it does not come back on when it is started again later on the same day.

The exact message is "Low Oil Pressure - Check Owners Manual".

ok

maybe just a very dirty engine, compliments of the previous owner. You can peer into the oil fill hole... if it looks too dirty, consider an oil flush before next oil change ;-)

for myself, whenever i take on a new car, i always like to develop my own personal history for the car... and that starts by changing all fluids first. It gives u a general idea of that else might be wrong. You're on the right track buddy :-)

cheers

DonJ · 08-31-2009, 11:22 AM

I agree Darkhorse, I'm keeping track of everything I do to the car.

Next is to drain the tranny fluid and put in a new filter and also drain the differential and put in new gear oil - I have no idea if it has been done. The previous owner bought the car in 2001 and he does not recall ever doing any of that. He bought it from the original owner but there's no records of what has been done.

He did put in a new water pump and hoses back in 2004 (He gave me the receipts to show that was done). It's probably due for a cooling system flush soon. He also recalls putting in a new head gasket but doesn't have the receipt for that.

So far in three months I have put in a new battery, new fuel pump and in line filter, new Crank Position Sensor, new drivers side door actuator cable (wouldn't open from inside), fuel tank door hinge, light bulbs in on-board computer, new right front side marker light and tracked down something that was draining battery (atleast I think I fixed that one).

But I got the car for $800 knowing that it needed some attention (it has 162K miles on it). The next big project is to replace the thrust rod bushings. I think I'll just buy the new arms with bushings and ball joints already installed. I've never done any work like that on a car - so wish me luck - I've found plenty of info on line that gives really good directions on how to do this, so I think I'll be able to get it done with out too much trouble.

DonJ · 08-31-2009, 04:16 PM

I found more info on this.
There is a check valve in the oil filter housing. If it goes bad, it allows oil to drain out of the housing therefore it takes abit longer to build up pressure because it is filling the housing back up. When I changed the filter, I did notice the oil draining out - I guess it isn't supposed to do this. So that explains why I would get the message after the car sat for a while but I wouldn't get the message when started back up later on (oil hadn't completely drained out). Here's a link with more info ...

BMW E34 Website

DonJ · 09-04-2009, 09:05 PM

I pulled the oil filter back out today and the little check valve wasn't seated all the way in the opening. Apparently a previous owner ground the little tabs that hold it in place. The check valve looked OK and I popped it back in. But I don't have any way of securing it down in there.
It's only in the morning when I get the oil pressure message and then it builds up to an acceptable pressure. It takes about 3 or 4 seconds to build up.

I've looked around, there's a few web sites on how to "fix" it but it's more like a temporary bandaid - until it pops out again I'm guessing. Ebay had a used housing for $30 - but you risk getting another bad one. New filter housings cost $300.

<sigh> If it's not one thing - it's another.