Potentially Serious Problem

[Newjack]

For the past couple months I have been dealing with a faulty oil level sensor. Well, at least I was pretty sure it was a bad sensor. Most of the time it would come on, only to check my oil and find out it was still within an acceptable range.

Well, in the last month it had been coming on a lot more than usual. So I checked it just to make sure. Sure enough my dipstick is telling me my oil is right at the minimum level. So I add in about 300ml of oil. The very next day as soon as I get home from class I park my car and the light turns on as soon as the engine shuts off. I check the oil level again, and it is maybe a little lower, but definitely above the minimum and in an acceptable range. (God damn faulty sensor).

Last week the oil light starts coming on again (this time more than usual) So I check the oil level this past Sunday. My dipstick says it is below the minimum. Fuck.

I put the car in the garage and put it on ramps. Removed the underbelly shield to get a better look at the OFHG area as well as checking on my oil pan. No leaking oil. No signs of oil burning from either location. So I look on the top of the car, by the oil filter as well as around the valve cover gasket. No oil present. No burning oil smell. No white smoke when the car is running. Nothing.

I ask my stepdad what I should do about it. He says "You got those sparkplugs a while ago, we can do your plugs and see how bad they are" Ok.

Changed out all of the spark plugs and this is what I found. (OE spark plugs were still in the car. 97k on these plugs. Still said BMW on them so I know they are OE)

From left to right Cylinder 1,2,3,4,5,6



Cylinder 1,2,3



Cylinder 2(barely visible, far left) 3,4



Cylinder 4,5,6






So my question is this; what is my car telling me? Where is my oil going?
Do I need to do my CCV? Is it possible that my oil is leaking into my coolant system?

I'm at a loss here...

[johnnyrad]

Yea they certainly needed changing. I see the threads on the first four plugs have oil coating them, but plugs five and six almost nothing. Have you replaced your valve cover gasket? I'm certainly no mechanic, just a thought tho.

[Newjack]

Valve cover gasket has not been replaced. I don't think the PO changed it out either.

I have inspected the valve cover gasket and didn't notice any leaking oil. I don't doubt that it needs to be replaced, I had planned on doing it when I redo my VANOS unit.

[danewilson77]

IDK. Seals may be going.

[LivesNearCostco]

If you're losing oil but it's not leaking onto the floor, underbody shield, or exhaust manifold, then it's leaving your engine somehow. This can be via failed CCV or bad piston rings letting oil get into the cylinders to burn up. Or aliens from Cowboys and Aliens decided they want black gold and have been stealing yours via teleportation. (That helps explain why oil prices are so high again.)

The VCG has a big rectangle that seals the perimeter of the VC and two rectangles with 6 holes (3 holes per rectangle) that seals the VC against the spark plug wells. Maybe in your case the center rectangles started leaking first, before the right/downhill side of the big VCG rectangle, which likes to leak onto the exhaust manifolds.

BUT, even if your VCG is leaking onto the plugs, I don't think it could leak as much oil as you say you're losing, unless your spark plug wells were full of oil. I say replace the VCG, but also look into:

1) CCV tests, either Zip-loc bag or blowing into the VC vent tube test.
2) Raise care safely and feel on top of reinforcement plate with paper towel. Leaking oil (or P/S ATF) can pool on top of that plate.
3) Hire Harrison Ford, Olivia Wilde, and Daniel Craig to get rid of the aliens

[Newjack]

Ah I knew I forgot to mention something.

When I checked my plugs, the spark plug wells were all extremely clean. To be more precise because I don't know the technical terms for this stuff, the cylinder where my coil park is inserted was clean.

1) Can you elaborate on how to test to see if my CCV is bad? Maybe a DIY somewhere?

2) I checked underneath the car and didn't notice any leaks. If it is leaking on the reinforcement plate, would I not have noticed it with right away with a quick inspection?

3)

[danewilson77]

Ah I knew I forgot to mention something.

When I checked my plugs, the spark plug wells were all extremely clean. To be more precise because I don't know the technical terms for this stuff, the cylinder where my coil park is inserted was clean.

1) Can you elaborate on how to test to see if my CCV is bad? Maybe a DIY somewhere?

2) I checked underneath the car and didn't notice any leaks. If it is leaking on the reinforcement plate, would I not have noticed it with right away with a quick inspection?

3)

Knowing that bit of additional data, I may be leaning toward ccv.

HTC Thunderbolt+TT

[Johnmadd]

I would agree with vcg, it leaked just like that on my e30. Should be an easy cheap fix im guessing if it is the vcg.

[zj96sc]

More serious (and less likely) than any of the rest, what what's your coolant level like?

[SoarinZHP]

I am leaning towards the VCG. Being the car resides in Maryland - I would do the CCV test or take it somewhere that knows how to test/diagnose it. You can do the test by running the car with the filler cap removed. Grab a plastic bag from a grocery story. Without letting go of the bag, stretch a portion of it taught and place it over the open filler hole. If there is gentle suction on it, your CCV should be good.

Also, if you are having sensor problems, replace the sensor next time you change your oil. It is very easy to do.