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.