Where is all the oil going?????

Hello Folks,

I have a 2003 325xi that just turned over 165K (I’ve had the car since 40K purchased in 2005). All is well with the car except that I seem to be going through quite a bit of oil. I usually have to add a quart every 800 miles or so – about every two weeks with the 80 miles a day or so I drive to work. This has been going on for about 6 months – but now seems to be getting worse. I don't smell any oil or antifreeze burning.

I questioned my indy non-BMW specific mechanic about this and he said there was a slow leak in the oil filter housing gasket. At home I park the same place and my car shows no evidence of leaking anything – same situation at work. From reading this forum I know that these engines will use more oil as they get older, but I wanted to check that this sounds normal to everyone here.

I wanted to get the thoughts with the experts here that a ‘slow’ leak in the oil filter housing gasket was the possible cause of my missing oil. I have no problem having the mechanic change out the gasket for me, but there are a couple of other repairs I need to do as well and I just wanted to prioritize things. I love the car and I plan on it seeing 200K.

Just to answer some of the questions I know I'm going to get asked:
-Indy mechanic quoted $300 for changing out the gasket
-I'm 9 months pregnant and live in NH without a heated garage so the chance of me doing any repairs myself for the foreseeable future is nil. (Although I have really enjoyed fixing small things myself and learning how the car worked in the past thanks to this forum).


Happy New Year to everyone.

Thanks,
Laurie

Leave it to my more knowledgable colleagues for a detailed response, but I had OFHG oil leak earlier this year, and it was obvious it was leaking from just a casual look. If you see no oil around the oil filter housing, your problem is likely elsewhere.

There's this cover under the engine which might collect some oil before it gets to the ground.

Originally Posted by lgr122

There's this cover under the engine which might collect some oil before it gets to the ground.

Oh - I see - that's probably why I don't see any on the ground. Thanks.

Originally Posted by shadow 2

Leave it to my more knowledgable colleagues for a detailed response, but I had OFHG oil leak earlier this year, and it was obvious it was leaking from just a casual look. If you see no oil around the oil filter housing, your problem is likely elsewhere.

I do see that there is oil around the housing - but not THAT much.

Huh, weird my 325i uses a quart every 800 miles or so too

I have changed the oil filter housing gasket.
I have changed the oil separator.
I have changed the valve cover gasket.

I still have to put a quart of oil in every now and then between oil changes.
It is what it is.

I had a leaky OFHG that used about a quart every 600-700 miles, changed it and now it doesn't use any significant amount at all. It may LOOK like a small leak, but any leak should be repaired as soon as you detect it.

Originally Posted by catso

I had a leaky OFHG that used about a quart every 600-700 miles, changed it and now it doesn't use any significant amount at all. It may LOOK like a small leak, but any leak should be repaired as soon as you detect it.

Thanks - that must be the case then. I would have never thought it would leak that much.

Thanks to everyone taking the time to respond - I really appreciate it.

Sent from my SAMSUNG-SGH-I747 using Bimmer App

I wouldn't pay more than $160 for the gasket to be done. I would also do the CCV as well which I think is the main reason.

For what it is worth I have a 2002 330i with 147k miles. I have no leaks and I add about 1 quart every 800 miles. The engine doesn't smoke at all, just uses the oil.

Originally Posted by JNMNL52

For what it is worth I have a 2002 330i with 147k miles. I have no leaks and I add about 1 quart every 800 miles. The engine doesn't smoke at all, just uses the oil.

That's way too much oil use. Change your CCV

Sounds to me that it's a failing crankcase ventilation valve, leaks usually aren't a quart every 1000 miles. Also the common leak places are likely to leak onto hot areas and smell. When a CCV valve fails the car burns the oil and runs slightly more coarse because it causes the vacuum system to work improperly. It's a gradual transition and is pretty unnoticeable until you address the CCV failure and feel the difference.

Here's my quick diagnosis (and I've written this in a few places on this forum already)

1. Take out the dipstick, examine the bottom (usually plastic and colored red or orange) if it for black sludgy oil residue, this is a sign of a failed CCV.
2. While the engine is idling remove the oil fill cap and then put it back on, make sure it't tight. While you do this listen carefully for changes or surges in the engine idle pitch, especially when putting the cap back on. If there's no change in pitch then the vacuum system may be faulty and it's usually due to a CCV failure. You can also remove the dipstick and listen for a change in the engine pitch.

A mechanic with the proper tools would seal a hose on the dipstick tube with a pressure gauge on it and look for negative pressure, if there's no negative pressure, change the CCV, it's not a particularly fun job but it's a common problem on these engines.

Originally Posted by DPP528

Here's my quick diagnosis (and I've written this in a few places on this forum already)

1. Take out the dipstick, examine the bottom (usually plastic and colored red or orange) if it for black sludgy oil residue, this is a sign of a failed CCV.
2. While the engine is idling remove the oil fill cap and then put it back on, make sure it't tight. While you do this listen carefully for changes or surges in the engine idle pitch, especially when putting the cap back on. If there's no change in pitch then the vacuum system may be faulty and it's usually due to a CCV failure. You can also remove the dipstick and listen for a change in the engine pitch.

A mechanic with the proper tools would seal a hose on the dipstick tube with a pressure gauge on it and look for negative pressure, if there's no negative pressure, change the CCV, it's not a particularly fun job but it's a common problem on these engines.

I can do that - thanks.

I don't believe the CCV has ever been changed.

Replace your CCV first, then the OFHG gasket if needed. The failing CCV may have also caused your valve cover gasket to fail due to the crankcase being pressurized. Feel around the valve cover to see if the gasket is leaking.

Originally Posted by SJBimmer

Replace your CCV first, then the OFHG gasket if needed. The failing CCV may have also caused your valve cover gasket to fail due to the crankcase being pressurized. Feel around the valve cover to see if the gasket is leaking.

If you replace the CCV, do the OFHG at the same time. It's very easy, inexepensive (less than $10) and removing the oil filter housing makes it much easier to get to the CCV. The OFHG is a got a limited life expectancy because of its design , so even if it's not leaking now, it will sooner or later. Consider it preventative maintenance.

Originally Posted by catso

If you replace the CCV, do the OFHG at the same time. It's very easy, inexepensive (less than $10) and removing the oil filter housing makes it much easier to get to the CCV. The OFHG is a got a limited life expectancy because of its design , so even if it's not leaking now, it will sooner or later. Consider it preventative maintenance.

That's a good point, and good advice. I must be still hung over from Christmas!