Losing Oil

[juliea_1962]

I'm losing oil (about a quart for maybe 250 miles of driving), and I'm trying to figure out the source of my problem.

- The car isn't leaking when it's not running. I've been carefully looking under the car, and there are no signs of leaks.
- I get blue smoke when I'm accelerating very hard. Otherwise, I don't see it.

Any ideas on what might be causing me to burn oil this way? Also, is it possible that I may have a leak that only shows up when the car is running?

Any suggestions appreciated :)

[e30this]

Leaky valves seals or bad rings??

[wolfgangstbd]

how many miles does your engine have

[e30trooper]

your burning oil dude, use 20/w50 . thats what i tell most pre 98's and older bmw owners to use. and if your still burning , you may have a bad head gasket or rings

[e30trooper]

btw how much do you add every 250 miles? my m10 leaks and burns about a qt. every 2 weeks . i work a oil change place so biggy for me so i just top off every week, but if you have no leaks then ur deff. burning crazy. Dont use 10/30 or 10/40. only 20/50.that should reduce the burning and at least make your oil last longer. also dont go over 3000 miles on that oil

[juliea_1962]

Thanks for all of the posts!

I'm not sure how many miles the engine has. It is a used motor from a junkyard that we just recently put in (about 6-7 wks ago). The engine compression tested well (Grade "A", whatever that means). It's an M42, and I've got it in a 1991 318is.

I would say that I lose about a quart for around 200-250 miles of driving. If I am burning that much oil, shouldn't I be able to see blue smoke from the exhaust? (I don't regularly. I really have to slam on the gas to get it to show...I've maybe seen it twice or three times since I had the engine put in).

Is it possible that there's a leak that only leaks when the engine is running? Where can I look to see if this is the case?

Thanks!

[juliea_1962]

Oh yeah, I was using 10/40, but I switched recently to 20/50 to see if that helps matters. Haven't done enough driving with it to tell yet.

[learningcurve86]

i was burning that much, when i took the head off the engine you could move the pistons back and forth a lot. so much that my mechanic friend said "i didn't know they could do that!"

:-/

[juliea_1962]

Ok, went leak hunting this weekend, and found oil spray all over the front of the engine, and back along the passenger side of the engine. Can't really tell where it's originating from. Any ideas what could cause this?

I'm planning on cleaning it up today and taking a closer look.

[Cobra Jet]

The best thing to do is get either Brakleen, Carb Cleaner, Simple Green or Super Purple and spray down the entire engine bay, including all of the front of the engine and underside. Hose it all off, let it dry completely - then if possible, put the car SAFELY on ramps or a lift, start it in neutral w/ e-brake on and check to see if you can locate the leak itself...

There's a number of spots it could be leaking from... if you say it's "spray", then my fist guess would be to check the camshaft positioning sensor at the very front of the head - this sensor is supposed to have a rubber o-ring which prevents an oil leak there...

Check the valve cover on the passenger side

check all around the front timing chain cover

check your oil pan gaskets

check the harmonic balancer seal to see if it's leaking - if that is leaking, you will get "spray" due to the pulley constantly spinning when the engine is running.

If you cannot detect a leak w/ the car at idle, take it off the ramps or lift and go for a 2-5 mile drive, then once you come back, check again as you should be able to locate it at that point...

post your findings

[BTP325ic]

i think all old ass e30s burn a lot of oil mines does all the time i think ia m gonna switch to 10/90 cuz of the heat here in texas.

[BraveUlysses]

i think ia m gonna switch to 10/90 cuz of the heat here in texas.

wat

[juliea_1962]

Thanks for the detailed post Phil. Where can I find the harmonic balancer?

[DuHast]

the harmonic balancer is another word for the crank pulley. look for the big pulley at the bottom of the engine, that's the harmonic balancer. It's basically a reg. pulley with a counterweight (sometimes, not on all engines in all cars) which reduces the vibrations produced by the rotating assembly in the engine.

Do yourself a favor and go to autozone (or whatever your local parts store is) and get TRACING POWDER. It's in a spray can. After you clean the whole engine down like said in a previous post, spray that whole side of the engine down with tracing powder. It will put a fine layer of white powder on the outside of the engine. Your oil leak should stick out like a sore thumb when encroaching on the white coating. There's ya leak!

[juliea_1962]

OK...the Simple Green was amazing! Had tried a bike chain degreaser (only thing I had on hand) before, and it did not work. Simple Green got the engine very clean with very little effort.

After cleaning, I ran it, and found oil in a couple of interesting places. The highest spot on the front of the engine was along the edge of the oil filter housing, where it attaches to the block. I also found a nice little collection of oil under the crank, but I'm wondering if it may have collected there after dripping down from the oil filter housing.

I also found oil along the passenger side of the block where it attaches to the oil pan.

Lastly, I found another nice collection where the engine attaches to the transmission.

Sounds like I have multiple leaks....unless you all think there's some way they could all be traced back one. I didn't drive my car, just let it idle on ramps.