[brewnami]

Anyone have an issue where the low oil pressure light comes on when it's cold? The light comes on for maybe 5 seconds and then shuts off. I've seen this issue with E46's, but I can't get any clear answer for E9X's. Car is a 2007 335i with just under 32K miles. JB4, DCI, catless DPs's, 30% E85 are the only mods. It's happened three times in the last couple days, but since it shuts right off, I'm guessing it's not actually low oil pressure.

Please only chime in if you're familiar with the issue... There are people on this forum that take their car to the dealership when the low tire pressure light comes on.

[enrita]

Did you check oil level?

[brewnami]

Originally Posted by enrita

Did you check oil level?

Yeah, iDrive says it's one notch below full... I really wish there was still a manual dipstick.

[3000GT MR]

What viscosity are you running? If you live in colder climates try a 5w30

[brewnami]

Originally Posted by 3000GT MR

What viscosity are you running? If you live in colder climates try a 5w30

I live in Austin, TX... I Just run the BMW Castrol synthetic 5w30.

[3000GT MR]

Originally Posted by brewnami

I live in Austin, TX... I Just run the BMW Castrol synthetic 5w30.

Sorry i couldn't see from my phone. Id say that's a little unusual l to see. I wouldn't sweat it just yet, keep monitoring for reoccurrence. Maybe someone in a colder region can chim in

[Spoolin1]

Just remember that high ethanol fuels will break the oil down (thin it out) over time and mileage, especially if the oil has a low TBN to begin with. A good diesel oil or premuim oil like AMSoil have a high TBN with good detergents to combat the oil thinning and breaking down. Also, a good oil with high zinc will help lubricate intricate parts really well and combat premature wear. I don't think the oil light issue has anything to do with the oil, just wanted to put this information out there.

[longliven54]

i am not sure if its related, but very well could be. my car always showed oil letter to be good, never full. my car doesnt have oil cooler and i filled 7 litres, yet the oil level bar would never go to full. i asked my service rep(who is very cool with mods) about this, and he mentioned that he sees a fair amount of 335s with failing oil level sensor. it is something that i would replace in future, but at this moment i change my oil every 8-10k kms and i usually retrive 6+ litres of old oil from the motor without ever topping up in-between oil changes.

[BMWM.D.]

Could be an issue with the oil pressure switch. It isn't something I've seen many problems with on these engines, but I see BMW has updated the part number on it 4 or 5 times. That's usually a sign there are issues with the part. It's a cheap and easy fix if so. Might be worth a try: http://www.ecstuning.com/Flyer-Forge...ort/ES2612420/

[Najjar]

I have the same issue when I start the car in the morning it would show the Oil Pressure Low light, then it disappears. I changed the oil to 5w30 Castrol Magnetic, the light didn't come on for a week then it appeared again. I think I have a problem in my oil sensor; it shows full all the time no matter what. I'm afraid that my car is consuming oil or is it the fuel or what else? I'm confused!

[BMWM.D.]

Originally Posted by Najjar

I have the same issue when I start the car in the morning it would show the Oil Pressure Low light, then it disappears. I changed the oil to 5w30 Castrol Magnetic, the light didn't come on for a week then it appeared again. I think I have a problem in my oil sensor; it shows full all the time no matter what. I'm afraid that my car is consuming oil or is it the fuel or what else? I'm confused!

The level sensor shouldn't have anything to do with the pressure warning. The level sensor measures oil level and temperature and is located at the bottom of the oil pan. The pressure switch is what detects oil pressure, and it is located on the oil filter housing.

I doubt your problem is your engine consuming massive amounts of oil. Over the years, I've found these oil level readings to never be super accurate. I don't think I'd be too worried about what you're seeing there. More than likely a pressure switch issue (like I mentioned) or something wrong with the oiling system (pump, etc.). It's hard to say without actually looking at the car. Might be time to hook up a mechanical gauge and do some monitoring.

[Najjar]

Originally Posted by BMWM.D.

The level sensor shouldn't have anything to do with the pressure warning. The level sensor measures oil level and temperature and is located at the bottom of the oil pan. The pressure switch is what detects oil pressure, and it is located on the oil filter housing.

I doubt your problem is your engine consuming massive amounts of oil. Over the years, I've found these oil level readings to never be super accurate. I don't think I'd be too worried about what you're seeing there. More than likely a pressure switch issue (like I mentioned) or something wrong with the oiling system (pump, etc.). It's hard to say without actually looking at the car. Might be time to hook up a mechanical gauge and do some monitoring.

Thanks for your reply. What I intended to say is that if the oil level sensor is faulty and there is an oil consumption the only thing that would tell me that the oil level is really low is the oil pressure sensor. Please correct me if I'm wrong?

[BMWM.D.]

Originally Posted by Najjar

Thanks for your reply. What I intended to say is that if the oil level sensor is faulty and there is an oil consumption the only thing that would tell me that the oil level is really low is the oil pressure sensor. Please correct me if I'm wrong?

I'd agree with that logic, but you'd need to have a massive oil consumption problem to lose almost 7 quarts in a week. It would take a VERY low oil level to trigger a low-pressure warning. I honestly think you'd have a lot of other noticeable issues if your engine was burning oil like that.

[brewnami]

Originally Posted by BMWM.D.

Could be an issue with the oil pressure switch. It isn't something I've seen many problems with on these engines, but I see BMW has updated the part number on it 4 or 5 times. That's usually a sign there are issues with the part. It's a cheap and easy fix if so. Might be worth a try: http://www.ecstuning.com/Flyer-Forge...ort/ES2612420/

I will pick up that part and swap it out and see if that helps. Thanks for the info!

[BMWM.D.]

Originally Posted by brewnami

I will pick up that part and swap it out and see if that helps. Thanks for the info!

I think it's worth a shot.

[Najjar]

Originally Posted by BMWM.D.

I'd agree with that logic, but you'd need to have a massive oil consumption problem to lose almost 7 quarts in a week. It would take a VERY low oil level to trigger a low-pressure warning. I honestly think you'd have a lot of other noticeable issues if your engine was burning oil like that.

That was really informative- thanks. I will change the switch, but before doing so, I would like to ask whether a faulty CCV would cause this, because while I was inspecting the DISA valve I found some oil in the intake manifold and when I drive the car it has SZZzzz (whizzing) noise, but it doesn't make any noise when idling. Should I change the CCV? Would a faulty CCV eat oil?

[BMWM.D.]

Originally Posted by Najjar

That was really informative- thanks. I will change the switch, but before doing so, I would like to ask whether a faulty CCV would cause this, because while I was inspecting the DISA valve I found some oil in the intake manifold and when I drive the car it has SZZzzz (whizzing) noise, but it doesn't make any noise when idling. Should I change the CCV? Would a faulty CCV eat oil?

DISA valve? Did you swap out your N54 for an N52? . Ok, that was a joke, but the N54 doesn't have a DISA. That's the dual (or 3) stage intake manifold runner valve found on naturally aspirated BMW engines.

Oil in the charge piping and intake manifold is pretty normal. The N54 has a 2-stage crankcase ventilation system. When in turbocharged mode (boost in manifold), oil vapors are dumped into the rear turbo inlet. This is where the oil in your intercooler or charge piping comes from. When in naturally aspirated mode (vacuum in manifold), the oil vapors are sucked into the intake ports via passages in the valve cover.

When you say CCV, do you mean the check valve that RB sells? The N54 really doesn't have a PCV valve (though everyone calls it that), but instead uses a calibrated orifice with a check valve to control crankcase vapor flow into the intake manifold. If this check valve fails or leaks, boost can enter the crankcase. There is also another check valve located in the vent hose that goes from the valve cover to the rear turbo inlet.

If you suspect oil consumption issues and have some mileage on the engine, I'd probably replace the valve cover and vent hose. The cyclone separators and related parts are all integrated into the cover and aren't replaceable. RB sells an "improved" check valve, but that's all that can be serviced.

Issues with the crankcase ventilation system can definitely cause oil consumption. I just don't think it's causing your oil level or pressure light issues.

[JamesM3M5]

Where do you buy filters / where do you get your oil changed? We see a LOT of cars with crappy filters that collapse and LAZY oil change monkeys that do not bother to put new o-rings on the filter cap stem. It can result in the oil leaking out of the filter housing after sitting parked for a while.

[BMWM.D.]

Originally Posted by JamesM3M5

Where do you buy filters / where do you get your oil changed? We see a LOT of cars with crappy filters that collapse and LAZY oil change monkeys that do not bother to put new o-rings on the filter cap stem. It can result in the oil leaking out of the filter housing after sitting parked for a while.

Agreed. Most of the aftermarket filters aren't up to the task.

[Spoolin1]

I use a wix oil filter with AMSoil. Anyone know if wix are ok to use? I believe they are pretty good filters. Have not had a problem yet.

[BMWM.D.]

I use OEM parts whenever possible on these cars. I'm not sure about Wix in particular, but I've seen a lot of aftermarket BMW oil filters fall apart when opening the housing for service or repair. Not good.

[akotten]

I've run 0W-40 with an OEM or Mann filter ever since I've bought it. From 90* days to -10* days, and I've never seen this. It's a 2007 with 108k miles.