Disappearing oil

[pknlotpmp318]

About a month ago i changed my oil and put in a gallon of Pennzoil 10w-30 (Conventional oil). 2400 miles later i check my dipstick and its DRY. I put more oil in it and it takes in 2 and a half quarts. I take it to a mechanic and they check under the car and it does have and oil leak (there are hanging drops on the oil pan and the catylitic converter has some on it), but they say that most of the problem is blow by. My car doesn't smoke though, but i have been driving it hard and fast for the past few weeks. (It's hard to resist going 90 on an open highway between school and home ). I don't know what I'm going to do as of now, for I don't know whether my loss of oil is just from driving hard, of if there is a lot of blow by. But my future options are either to fix my engine, get another M42, or maybe a 6 cylinder swap. Some info on the general prices on each of these options would be appreciated. Thanks!

Btw i would want a 6 cylinder out of a 325 rather than an m3, unless i can find a good deal. lol

[Mallard]

wtf is blow by? sorry for sounding stupid ..

have a look at the bolts that hold the oil pan up, these loosen over time and let oil leak. Also have a look at the oil filter housing.

i doubt your burning oil if most of it seems to be under yur car..

Try parking over a cardboard box flattened out and see how much oil drips.

[JNCoulombe]

1) You definitely should be checking your oil more often than every 2,400 miles. It is a very good idea to check every time you fill up the gas tank.
2) Check the area aroung your oil filter. There is an O ring on the filter housing that often fails and looks like a minor drip that is really hard to locate.
3) Oil consumption of almost 1000miles per quart is really not bad and probably not a reason for major repairs such as a ring job or replacement of valve guides.
4) The blow by explanation sounds very dubious to me especially if there is no evidence of blue smoke. Have a friend follow you for a bit to watch your exhaust. If you get blue smoke at shift points or after idling that suggests leaking valve guides which you might not see in your mirror.

For Mallard: Blow by is the passage of combustion gases past the compression rings into the block. In USA cars since 1962 these gases along with oil that vaporizes from heat and oxidation then gets sucked into the combustion chamber by the positive crankcase ventilation system and burned.

[pknlotpmp318]

Thanks for the info. Since i've owned the car, I've put about 26000 miles on it and have changed the oil every 3000 miles. I never noticed a lack of oil until the last two times i've changed it. I put a gallon of oil in, and when i change it only half a gallon (or 2 quarts) comes out. And this time at 2400 miles 2 and a half quarts were gone. For the past few months on the weekends i drive home from school on a road with no cops and i usually do about 80-90 for 30 miles. It took seeing the dry dipstick for me to realize that this MIGHT be bad for my car. I havent gone above 70 since then and that was only for a minute. I plan on changing my oil soon and when i do, i will drive normally and see how much oil i have after 3000 miles. Now that i think about it i was pretty stupid to do that but I've learned. haha. Hopefully this won't be too costly of a learning experience.

[acevedo12]

i had the same problem except mine turned up to be a bad gasket. that was definitely not a fun fix.

[hotmilk400]

i dont think the high speed of 90 (which isnt that high, since i did 90 mph from Pennsylvania to Alabama over the summer, and the speed limit is about 75 + on those roads) will effect oil like that. atleast not to that extent. u are clearly burning it or losing it, or both.

the lazy mans way to fix the problem is to just check/add oil every time you fill up. you dont want the oil to be emtpy, or you will destory your motor. take it to the mechanic and let them figure out whats wrong with it. and.. i would recumend going to someone else since the last guy didnt fix anything.

fixing the problem isnt going to cost you that much, y it wasnt fixed awhile ago is past me. if you think it will cost to much, forget getting a new motor for such a cheap fix.

liek i said, since you SEE it is dripping out of the motor, then driving has almost nothing to do with it. you shouldnt lose almost any oiol withing 3000 miles, let alone going dry within 2400 miles.. major leak

check your spark plugs for oil, check the o-ring for the filter.. make sure the oil pan is tight, and not cracked.

[JNCoulombe]

Driving the car at 80-90 mph should not be at all bad for the car (excepting the obvious dangers of a blown tire, road debri etc etc). Not checking the oil between oil changes on a 12 or so year old car, on the other hand, may well be. If you run out of oil it won't matter if you are driving 25 or 90 - the engine will be toast. Only one gallon at oil changes also sounds like too little oil. Aren't you changing the filter too or just the oil? The oil filter housing is really the most likely culprit for your loss of oil even though only a small amount of oil seems to be leaking.

[adamud]

I say check the oil filter housing to. Grab a flash light and shine it down by the housing (from the top, no need to jack the car up). If there is a pool of oil on top of the motor it is the filter housing.

[pknlotpmp318]

I change the filter every time i change the oil. And one gallon fills the engine up to the point where the oil is between the lines on the dipstick. I will put a little more in next time though. And i will check this problem out more in depth this weekend. I've got finals to study for. lol

[JNCoulombe]

Your oil level should be at the top line on the dipstick after you run it to refill the filter housing.

[tiFreak]

Originally Posted by JNCoulombe

Your oil level should be at the top line on the dipstick after you run it to refill the filter housing.

no, it doesn't have to be, between the lines is fine

[JNCoulombe]

While between the lines might not ruin anything, why start out down on oil? I would be pissed if I paid someone for an oil change and they only put in one gallon and left it a half liter down.

[Will'sBimmer]

Originally Posted by adamud

I say check the oil filter housing to. Grab a flash light and shine it down by the housing (from the top, no need to jack the car up). If there is a pool of oil on top of the motor it is the filter housing.

+1 I have the same problem you have. My oil filter housing gasket needs to be replaced. It is a common problem. I also have hanging drips of oil from oil pan, trans, and other parts. That is just from where the oil has been leaking from the housing and when you drive the wind blows it onto the oil pan, trans, and anything else that gets in the way. So instead of just swapping motors, just order the cheap gasket, i think it is under 20 bucks, and replace it. May take some time but it will be worth it, cheap and will fix the problem. But I say since it is leaking do like I do and check your oil often. Running low is never good since it can lead to the break down of other gaskets and cost you more time and money. I have to put oil in mine not to often but I make sure it is between the lines, like in the middle. And driving fast won't hurt it but driving fast while low on oil will not be good.

[Xenocide]

Originally Posted by Will'sBimmer

+1 I have the same problem you have. My oil filter housing gasket needs to be replaced. It is a common problem. I also have hanging drips of oil from oil pan, trans, and other parts. That is just from where the oil has been leaking from the housing and when you drive the wind blows it onto the oil pan, trans, and anything else that gets in the way. So instead of just swapping motors, just order the cheap gasket, i think it is under 20 bucks, and replace it. May take some time but it will be worth it, cheap and will fix the problem. But I say since it is leaking do like I do and check your oil often. Running low is never good since it can lead to the break down of other gaskets and cost you more time and money. I have to put oil in mine not to often but I make sure it is between the lines, like in the middle. And driving fast won't hurt it but driving fast while low on oil will not be good.

I think it was $11 to fix mine...

plus curse words, sweat and blood.

Pretty simple fix, i did my valve cover gasket at the same time since I had to change the oil anyways. Hardest part of the install was getting the alternator in/out of its bracket. I had to wedge a think steel rod in-between the alternator and its cradle to wedge it out. You DO NOT want to hit the alternator with a hammer.

[BlueCalifornia96]

I can't find the exact thread regarding the repair, but this one is close. I had a mysterious oil leak as well, it looked like it was coming from around the head and was hard to identify even after degreasing. I signed on here and read about the oil return gasket area leaking. The parts were $25 from the dealer - which had them in stock: 2 o-rings and 1 square gasket. It took me about 4 hours to finish the job and the leaking has stopped. The two 0-rings (which should be compliant, round rubber) were worn flat and hard like plastic. The other gasket seemed okay, and was probably not leaking, but replacing is necessary. Without seeing the car, a reputable local shop speculated that it was probably a head gasket. For the time and the money this is an easy, inexpensive fix. Thanks to those that had the information and saved me an engine swap!!