Strange Oil level problems

[Dave P]

First post here but i've been searching this board for a year or so to diagnose and fix stuff on my 1991 525 M50 manual euro The Knowledge here has saved me £££

Had this car for 1 year, its in good shape and I have replaced radiator,water pump, themostat,diff and gearbox (both were shot when I bought it !!)
Car condition :- 162k miles,No coolant loss, no oil in coolant, no smoke.
Car is used as a daily driver around town stop/start traffic 30-50 mph and getting 22/23 mpg. Some higher speed motorway 70-100mph maybe 100 miles a week

Ok enough of that heres the problem and I've been living with it for a while but its starting to bug (and worry me) now

After driving at highish speed for say 10 mins when I shut down engine I get the oil level low warning. Dip stick shows oil level low but if the car is left for a hour oil level is back to normal. Seems the oil is taking its time to drain back into the sump. Is this a blockage in the oil ways ? or Oil pressure regulator/ oil pump/Oil filter canister issue ?

I have also noticed oil seeping from the PCV and running back through the hose into the intake boot through the MAF into the bottom of the air filter housing. There is no change in revs when I remove oil filler cap or dipstick and if I put a plastic bag over the oil filler hole it blows out slightly ( is it not meant to suck it in ?) Seems like there is to much pressure in the system.

Had the valve cover off to replace gasket (oil in spark plug wells) and there is no sludge and every thing looks nice and shiny.

Can any of you gurus point me in the right direction

Dave

[Akhil]

when I was using 15-W-40 oil, but It stoped since I started using 10-W40. Also, do you see any leak aroung oil filter housing? 2 round holes(valve) in housing might have leak which happand only at high RPM (high oil pressure).

Akhil

[Dave P]

when I was using 15-W-40 oil, but It stoped since I started using 10-W40. Also, do you see any leak aroung oil filter housing? 2 round holes(valve) in housing might have leak which happand only at high RPM (high oil pressure).

Akhil
Akhil
No leaks around filter and using Mobile 1 0-30
Dave P

[Akhil]

When did you last replace breather connector / O-Ring. It could be oil coming out of brether hose. Old engine has lot of blow back. Once I tried italian tuneup with and my engine spit whole lot of oil from breather hose and valve cover. On lower RPM same thing works great. After driving on high RPM park the car at clean spot and seem if you have any leak first. If you don't then it might be cloged oil filter or some other oil circulation route.

Good luck
Akhil

[Dave P]

Akhil
Thanks for replys

When did you last replace breather connector / O-Ring. It could be oil coming out of brether hose. Old engine has lot of blow back. Once I tried italian tuneup with and my engine spit whole lot of oil from breather hose and valve cover. On lower RPM same thing works great. After driving on high RPM park the car at clean spot and seem if you have any leak first. If you don't then it might be cloged oil filter or some other oil circulation route.

Good luck
Akhil
Breather connector/O- ring is on valve cover at front of engine above oil filter with hose to intake boot and smaller one to inlet manifold right ?. Never been replaced ! Blow back ? is this from the top of the engine ie in the valve cover ?
Can any body describe the oil circulation route where does the oil drain back into the sump from ?
Dave

[Dave P]

Cschollum


if you check the dipstick straight after shutting down the engine, then its quite normal for the level to be low, it will take a little while to drain back, not an hour, but a good few minutes

you say an hour, but you dont say if you checked after say 10 minutes

Yeh get your point. I am gong to monitor how quick it takes to level off more closely,but if this is normal how come I get the warning. The level is below the bottom line and when it levels off it is just below the top line. thats 1 ltr of oil !
Dave

[632 Regal]

I would render 2 guesses, your canister has a leaky check valve and while the engine is running its low...or...

maybe the head is full of sludge and is trapping the oil from draining back. you may be able to peek in there through the filler?

keep us posted.

[Dave P]

I would render 2 guesses, your canister has a leaky check valve and while the engine is running its low...or...

maybe the head is full of sludge and is trapping the oil from draining back. you may be able to peek in there through the filler?

keep us posted.
Regal
Thanks for input, Had the valve cover off and it all looks very clean but I will take another look.How many and where are the return lines ,is it safe to poke some thin wire down them ?
Will check canister. the valve is to keep oil in the canister when engine is stopped correct ? so what would faulty condition be ?
Dave

[Akhil]

Dave, you are right about breather ture, Do you see area and tube oilish or wet after driving little bit on high RPM. I had similar problem, what was happening, that at high RPM oil pump was pushing more oil to valve cover than return line can circulate it back, and that extra oli was spitting out through breather ture into intake boot and around connector b'coz of old O-Ring. I replaced all O-Rings on it route and also 2 O-Rings in oil filter housing check valve, they were leaking badly, but only at high RPM.

Dave, you did tell us whether you have any leak in your engine or not? Are you loosing oil? That will help us, let us know.

Good luck
Akhil

[ryan roopnarine]

the sensors do go bad, you know? have you determined how long it takes for the oil level on the dipstick to return to normal? i would fault that sensor for being sticky before i suspect other parts being bad, as on the rare occasion where my oil goes below 1 qt, the sensor may give one or two more "engine oil low" warnings before returning to normal after being topped off.

[Dave P]

Dave, you are right about breather ture, Do you see area and tube oilish or wet after driving little bit on high RPM. I had similar problem, what was happening, that at high RPM oil pump was pushing more oil to valve cover than return line can circulate it back, and that extra oli was spitting out through breather ture into intake boot and around connector b'coz of old O-Ring. I replaced all O-Rings on it route and also 2 O-Rings in oil filter housing check valve, they were leaking badly, but only at high RPM.

Dave, you did tell us whether you have any leak in your engine or not? Are you loosing oil? That will help us, let us know.

Good luck
Akhil
Akhil
Am going to replace o ring on that pcv connector. The connector itself seems ok but is not a tight fit in the valve cover
as for oil leaks well did have slight one from valve cover into sparkplug at cylinder 5 and from outside at rear of engine. Have replaced valve cover gasket
As for oil filter housing am looking at that now. How do you replace o rings,do you have to remove housing from block ? if so I could replace gasket at same time
Dave
Dave

[Dave P]

the sensors do go bad, you know? have you determined how long it takes for the oil level on the dipstick to return to normal? i would fault that sensor for being sticky before i suspect other parts being bad, as on the rare occasion where my oil goes below 1 qt, the sensor may give one or two more "engine oil low" warnings before returning to normal after being topped off.

Ryan
Yeh kinda had that in mind. Bentley shows two sensors, static for engine off +ignition on and dynamic for engine running. I only ever get the warning when I switch engine off never when running.
Dave

[Akhil]

non-replacable (according to BMW ;) ) and asking me to replace whole housing ($1000 + parts and labor), But I did it any way. The only problem is that, since that O-Ring is not available as replacement part, you will have to make trip to diff auto parts store to get exact match. But I found it any way.

Taking out those O-Rings are easy when you take housing out but if yous housing gasket is OK, then just for O-Ring you should be able to take out without taking housing out. Its kinda PITA job, you should have very thin and fluxible hand for this job. Just take a micro screw driver (Flat, NOT phillips) and push a locking pin ( C shape ) in hole inward and pop the pin out. Now taking the valuve and o-ring out need another person and will also create a mess. Cover valve hole with you hand and ask someone to start the car just for a second or 2, that will pop valve out b'coz of oil pressue, since locking pin is out. You will see a black o-ring in that valve. Repeat the same process for 2nd valve. Take both o-rings and run for store. If can't find exact then find the closest match which is thicker than the old one but apprximatly same diameter, since it has to seal. It cost only $2 but might take an hour to couple hours, depending on you skill of visualing things without seeing it.

Note : Before stating this, take a good look inside those valve hole with a mirror on stick (inspection mirror), because you will have to do this job without seeing any thing in real. just have that pic. in you mind and feel that with your fingures and do the job, since its under intake main fold and at very tight space.


If you stiil have question, let me know.

Good luck.
Akhil

[Dave P]

[QUOTE=Akhil]non-replacable (according to BMW ;) ) and asking me to replace whole housing ($1000 + parts and labor), But I did it any way. The only problem is that, since that O-Ring is not available as replacement part, you will have to make trip to diff auto parts store to get exact match. But I found it any way.

Taking out those O-Rings are easy when you take housing out but if yous housing gasket is OK, then just for O-Ring you should be able to take out without taking housing out. Its kinda PITA job, you should have very thin and fluxible hand for this job. Just take a micro screw driver (Flat, NOT phillips) and push a locking pin ( C shape ) in hole inward and pop the pin out. Now taking the valuve and o-ring out need another person and will also create a mess. Cover valve hole with you hand and ask someone to start the car just for a second or 2, that will pop valve out b'coz of oil pressue, since locking pin is out. You will see a black o-ring in that valve. Repeat the same process for 2nd valve. Take both o-rings and run for store. If can't find exact then find the closest match which is thicker than the old one but apprximatly same diameter, since it has to seal. It cost only $2 but might take an hour to couple hours, depending on you skill of visualing things without seeing it.

Note : Before stating this, take a good look inside those valve hole with a mirror on stick (inspection mirror), because you will have to do this job without seeing any thing in real. just have that pic. in you mind and feel that with your fingures and do the job, since its under intake main fold and at very tight space.


If you stiil have question, let me know.

Good luck.
Akhil[/QUOTE

Akhil
thanks for the above. but im getting a bit confused now. where is the valve you are talking about,inside canister or on body of canister ?

Just for my understanding of the route the oil takes through the engine and the operation of the valves (maybe someone can correct the following if its wrong)
1)Oil is picked by pump from bottom of sump
2)delivered to oil filter through spring loaded non return valve in bottom of canister which closes when engine off to keep oil in filter canister
3)oil forced through filter from outside to centre and then into rest of engine
4) second valve in bottom of canister to bypass filter in event of total blockage and possible oil stavation

Or is the above the opposite way around. Oil forced from centre of filter to out side ???

Sorry about the ramble but when I am fixing stuff I always find it helps to know the way a system is meant to work !!!

[Akhil]

Value are in filter housing, through 2 holes from outside. Locked by locking pic ( C shape). You should be able to feel it when you put your finger in back of housing under intake mainfold, right next to oil pressuer switch. You should take out connector or pressure switch while doing this, just in case you might brake it.

Akhil

[Dave P]

Value are in filter housing, through 2 holes from outside. Locked by locking pic ( C shape). You should be able to feel it when you put your finger in back of housing under intake mainfold, right next to oil pressuer switch. You should take out connector or pressure switch while doing this, just in case you might brake it.

Akhil

Thanks Akhil
will check it out,though work commitments now in the way for a couple of weeks. will let you know how I get on.
Dave

[Akhil]

Drop me a email if you still have any question.

Good luck.
Akhil