Oil has to be going somewhere

[dkirch]

I need some clarification on oil consumption on a 01 E46 330 Convert with 152,xxx miles. I bought the car as a CPO with 26,xxx miles on it. Much to the dismay of the dealer I have had the oil changed at 5k to 7k miles since I have owned the car. Use only BMW oil. This was evident when I replaced the valve cover gasket last July. Valve train looked factory fresh no oil sludge at all. I only use the car for pleasure and maybe put 5,000 miles on it a year. mostly driving around town and the 3 to 4 trips to LimeRock a year and a couple of trips to the eastern end of Long Island. The car runs great does not smoke on start up or leave any oil spots on the garage floor.

In April I brought the car to the dealer to take advantage of an oil service coupon and have the failed oil level sensor replaced that I had bought on line, which has recently failed again in a couple of weeks since it was in the car. I asked they check the car's oil separator valve as it seems to use around 1qt of oil around 1+k. Told me oils separator valve ok but I have some weeping at the oil filter housing not bad and $685 to fix.

I went to the Grand Am race last weekend. A round trip distance of 256 miles at mostly highway speeds 70 and some 80+mph. I had checked my oil before I left and topped up to full. Checked it again at Tues. AM as I was going to take another 170 mile trip that day and as always check my oil before starting out. To my shock I was down 1 and 1/2 qts of oil. In my panic I topped up the oil and took the car to the dealer. I was told that 330's are supposed to consume a qt of oil in 750 miles and I am a little under that target but given the age and miles on the car it is not bad. Well in my mind 1-1/2 qts in 256 miles is not 1qt in 750 miles and is bad. So when I told the dealer just that. I am told that the oil blew out of oil filter housing gasket as the oil pressure raised when the car was at speed. When I questioned that a 1-1/2 qt of oil is a lot of oil and I am not getting any drips on the garage floor, The oil has to be gong somewhere. I was told because BMW's have a pan that encloses the bottom of the engine compartment. The oil drips onto the pan and is blown out from behind the car when I am driving. (gotta love dealers) I have rechecked everything i.e. hoses, suspension parts, the magical pan; all dry. There is some oil residue on the engine block by the oil housing but not wet drips like the valve cover gasket failure just a residue.

I am thinking the oil is being consumed by way of the oil separator valve at speed. Thus not causing any pooling of oil that would eventually drip off the engine/components on to the garage floor. Could the oils separator be the problem? I have checked a November forum and the consciences of opinions, seem to point in this direction. I just want to figure it out before I send $685 to replace a $12 part and still have the same oil consumption problem.

Sorry for being so verbose but wanted to give as much background as I could. Would love to hear from anybody that has worked through the same problem.[/b]

[edw1]

In April I brought the car to the dealer to take advantage of an oil service coupon and have the failed oil level sensor replaced that I had bought on line, which has recently failed again in a couple of weeks since it was in the car. I asked they check the car's oil separator valve as it seems to use around 1qt of oil around 1+k. Told me oils separator valve ok but I have some weeping at the oil filter housing not bad and $685 to fix.

Does that dealership service department have a magic oil separator divining rod? If so, they need to send it out for recalibration. If the car is consuming oil and the oil separator is original, it needs to be replaced.

I went to the Grand Am race last weekend. A round trip distance of 256 miles at mostly highway speeds 70 and some 80+mph. I had checked my oil before I left and topped up to full. Checked it again at Tues. AM as I was going to take another 170 mile trip that day and as always check my oil before starting out. To my shock I was down 1 and 1/2 qts of oil. In my panic I topped up the oil and took the car to the dealer. I was told that 330's are supposed to consume a qt of oil in 750 miles and I am a little under that target but given the age and miles on the car it is not bad. Well in my mind 1-1/2 qts in 256 miles is not 1qt in 750 miles and is bad.

1 qt per 750 miles? Please post the name of the dealer service department that told you that. Any shop feeding that line of crap to a customer deserves to be publicly outed. 1qt/750 miles is rebuild territory.

[sgoatley2001e46]

I'm with Ed on this one. If you're consuming that much oil, and haven't yet had the oil separator done at 150K+ miles, it needs to be replaced. This is common on BMW's at this mileage, and this is especially true for cars that don't put that many miles on, and do mostly local driving.

I'm in the same boat as you. I have a 2001 e46 (mine is a 325ci) with 147K miles, and change my oil on 4K intervals, and I just did the oil separator last year. Guess what? Oil consumption went down.

As for the dealer... probably not to be trusted. I had my car in for a service (like you, I had a coupon), and they told me it needed replacing. A few months later, I was back and the technician failed to report it, and I hadn't yet replaced it. It's a costly service to get the oil separator replaced, but I'd recommend getting it done. Look for an independent shop with BMW trained technicians. Try using Shade Tree Garage in Morristown, NJ. They're trained, have all the technology the dealership has, without all the BS. They're also a club sponsor, and do 99% of the work on my car.

[dkirch]

Thanks for the input I greatly appreciate it. You have confirmed what I expected about the oil separator valve all along. it needs to be replaced.

I have a problem wrapping my head around a manufacture like BMW, would design a car that would consume a 1 qt of oil every 750 miles.

I have been to several of our meetings at Shade Tree and like speaking to John and Dan. I am calling them now. I went to this dealer as he also is one of our club sponsors.

Does anyone have an idea of what should I expect as normal oil consumption? My buddy has a 06 e46 325 and he seems to never need to add oil between oil changes of 7k miles.

[sgoatley2001e46]

I never have to add oil to my car. I wasn't starting to consume any until the separator became a problem. Even at that, I don't think I was burning more than a quart between 4K oil change intervals. Now, I don't burn any. Get it fixed, and you should be "like new". I think you'll be very happy with the result.

FYI - I've never bothered to change my oil level sensor either. The light goes on and shuts off without fail every time I start the car. I just prefer to use the dipstick. It's hardly worth the money it costs to replace it.

[jnscaldwell]

I did the oil separator and all associated hoses with the upgraded (insulated) pieces last year. The oil stand gasket was bad and leaking so replaced that too. This is on a 2004 E46 with M54B25. This engine burns zero oil. I do oil changes every 7500 miles (anything else is overkill and I have the Blackstone data to back it up). I NEVER have had to top the oil up, we've had the car since new and it's at 106K now. As Ed says if you are burning a quart every 750 miles you should be rebuilding. My race car with a bad oil pan leak doesn't even need an extra quart every 750 miles and those are hard track miles. Something is afoot and sounds like you need to start digging into the root cause of this.

[victory1auto]

Probably the most common cause of a sudden increase in oil consumption [not leakage] on the M52-M54 motors is the oil separator/crankcase-pressure control valve and its related hoses. In many cases, it is not the valve itself that fails; rather its drain, which uses an annulus in the dipstick tube, plugs up.

There is a test, using a manometer to measure crankcase pressure, that is used to check the valve. I have seen cars with perfect crankcase pressure still consume oil because the valve's drain was obstructed.

Since the valves are prone to other issues, the usual fix is to replace the valve and ALL associated hoses. I recommend the dipstick tube be replaced as well.

As Jeff C. points out, there is a "cold weather" option on the new valve. I don't know that this option does anything for you in this climate [perhaps it is beneficial for cars enduring short trips in cold weather], but I don't think it hurts to have it.

[TimCircleBMW]

I second the dipstick tube as the part has been updated to allow better flow.