Help: engine oil leak

bkfastwagon · 08-10-2019, 03:56 PM

Hello, I'm in need of some wisdom from M3 veterans.

My wife and I went on a trip last night in our M3 and while cruising on freeway a low engine oil light came in out of nowhere. I checked the level just 30 min ago and showed normal level (just above midline between max and min).

I pulled over and opened the hood to find some engine oil splashes on the passenger side of the bay, mostly around the oil cap. I thought the cap might have leaked. I put in a quart that I kept in the trunk and the level was back to max. No warning signs, no CEL and the car drove fine. We went back home to switch cars as we still needed make this trip. The level stayed Max during ~10 mile drive back home.

Upon returning from the trip today (m3's been sitting for about 18 hours) I found a puddle of engine oil underneath the car. Exclusively on the passenger side of the car. Some oil could be seen on the passenger side front wheel well as well.

I'm going to call my mechanic first thing in the morning Monday, but obviously it's concerning.

Is there a way to find out the oil level without turning on the car? There's no dipstick.

Any insight would be appreciated.

msan · 08-10-2019, 04:02 PM

Sorry can’t help much on why it’s leaking but as for the oil level I don’t think there is any way to check the level without starting the car and driving it. You could tow to shop or maybe do an oil change in your garage so you will know there is enough oil in there....just an idea.

bkfastwagon · 08-10-2019, 04:14 PM

Quote:

Originally Posted by msan

Sorry can’t help much on why it’s leaking but as for the oil level I don’t think there is any way to check the level without starting the car and driving it. You could tow to shop or maybe do an oil change in your garage so you will know there is enough oil in there....just an idea.

Thank you. Upon further search, it seems like faulty cap is a known issue and has caused similar leak in others. I just hope that's the case and nothing more serious.

oolas3 · 08-10-2019, 05:09 PM

I’m guessing it’s your oil pan gasket if there’s a “puddle.” The leaking cap tends to spray the oil around engine bay and not so much on the ground. If you are certain the oil was full or near full when you parked, I think you are ok with driving it to a shop. Just fill it up with the amount you think is on the ground.

Mvy · 08-10-2019, 06:50 PM

The valve covers also can contribute to cap leaks. Once the coating starts to bubble and flake, the cap wont seat and oil leaks. I replaced with a different cap recommend on this board and it didnt help. I replaced my valve cover and then it stopped. My leak was nothing like yours however. It was more of a trickle that annoyed me and smelled when it hit hot engine parts below it. There was noticeable weeping around the valve cover gasket as well.

pbonsalb · 08-10-2019, 07:15 PM

I’d guess cap or valve cover gasket. Run your hand around the side of the valve cover and head on the “down hill” sides (which are the 3 sides you can access).

bkfastwagon · 08-10-2019, 07:42 PM

Thanks for the input.

Btw, I looked at the different parking slots that I used for past couple days and noticed marks of small puddles there as well, which tells me the leak had been happening for at least couple days. My guess is that since my normal commute is short the leak had been small but last night's longer drive on freeway resulted in greater leak. Does this sound right?

drrust · 08-10-2019, 07:48 PM

I suspect it is the oil cap. If you haven't removed it and put back on you should be able to see oil escaping if someone revs the engine. If you remove the oil cap, try pressing down as you turn. Double check how much is leaking by looking while the someone revs the motor.

wfdeacon88 · 08-10-2019, 07:51 PM

Mine was not as dramatic, but my leak was the oil filter housing gasket. no idea if that's the case, but before changing valve cover gaskets, make sure that is checked by the shop.

bkfastwagon · 08-11-2019, 09:19 PM

Quote:

Originally Posted by drrust

I suspect it is the oil cap. If you haven't removed it and put back on you should be able to see oil escaping if someone revs the engine. If you remove the oil cap, try pressing down as you turn. Double check how much is leaking by looking while the someone revs the motor.

Thanks for the tip. I will try this. I did notice that when I opened the cap, it didn't feel as tight as it used to. So at this point, I am leaning towards leak from the cap but will see what my mechanic says tomorrow.

It's kind of crazy that there's no way to check the level w/o turning on the engine.

I don't think I will add more oil until I know what the level is. I doubt it leaked more than a quart, and I don't want to risk overfilling.

Will update tomorrow.

bkfastwagon · 08-13-2019, 08:24 AM

It was the cap. Replaced with a new one and hasn't leaked so far. Will see. Thanks for the input.

08-10-2019, 03:56 PM	#1
bkfastwagon Second Lieutenant 191 Rep 236 Posts Drives: 2011 e90 M3 Join Date: Dec 2017 Location: Boston, MA iTrader: (0)	Help: engine oil leak Hello, I'm in need of some wisdom from M3 veterans. My wife and I went on a trip last night in our M3 and while cruising on freeway a low engine oil light came in out of nowhere. I checked the level just 30 min ago and showed normal level (just above midline between max and min). I pulled over and opened the hood to find some engine oil splashes on the passenger side of the bay, mostly around the oil cap. I thought the cap might have leaked. I put in a quart that I kept in the trunk and the level was back to max. No warning signs, no CEL and the car drove fine. We went back home to switch cars as we still needed make this trip. The level stayed Max during ~10 mile drive back home. Upon returning from the trip today (m3's been sitting for about 18 hours) I found a puddle of engine oil underneath the car. Exclusively on the passenger side of the car. Some oil could be seen on the passenger side front wheel well as well. I'm going to call my mechanic first thing in the morning Monday, but obviously it's concerning. Is there a way to find out the oil level without turning on the car? There's no dipstick. Any insight would be appreciated.
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08-10-2019, 04:02 PM	#2
msan Major 403 Rep 1,171 Posts Drives: 2011 E90 M3 / 2012 X5 35i M Sp Join Date: May 2015 Location: Los Angeles, CA iTrader: (16)	Sorry can’t help much on why it’s leaking but as for the oil level I don’t think there is any way to check the level without starting the car and driving it. You could tow to shop or maybe do an oil change in your garage so you will know there is enough oil in there....just an idea.
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08-10-2019, 05:09 PM	#4
oolas3 Captain 388 Rep 876 Posts Drives: BMW Join Date: May 2015 Location: United States iTrader: (0)	I’m guessing it’s your oil pan gasket if there’s a “puddle.” The leaking cap tends to spray the oil around engine bay and not so much on the ground. If you are certain the oil was full or near full when you parked, I think you are ok with driving it to a shop. Just fill it up with the amount you think is on the ground.
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08-10-2019, 06:50 PM	#5
Mvy Captain 541 Rep 979 Posts Drives: 2008 E93 M3 Join Date: Nov 2014 Location: GA Peach iTrader: (0)	The valve covers also can contribute to cap leaks. Once the coating starts to bubble and flake, the cap wont seat and oil leaks. I replaced with a different cap recommend on this board and it didnt help. I replaced my valve cover and then it stopped. My leak was nothing like yours however. It was more of a trickle that annoyed me and smelled when it hit hot engine parts below it. There was noticeable weeping around the valve cover gasket as well. __________________ Harrop Supercharger, BPM Tune, K/W Coil over kit, Stoptek BBK, Magnaflow exhaust, ear to ear grin everytime I drive...
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08-10-2019, 07:15 PM	#6
pbonsalb Lieutenant General 5228 Rep 10,614 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	I’d guess cap or valve cover gasket. Run your hand around the side of the valve cover and head on the “down hill” sides (which are the 3 sides you can access).
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08-10-2019, 07:42 PM	#7
bkfastwagon Second Lieutenant 191 Rep 236 Posts Drives: 2011 e90 M3 Join Date: Dec 2017 Location: Boston, MA iTrader: (0)	Thanks for the input. Btw, I looked at the different parking slots that I used for past couple days and noticed marks of small puddles there as well, which tells me the leak had been happening for at least couple days. My guess is that since my normal commute is short the leak had been small but last night's longer drive on freeway resulted in greater leak. Does this sound right?
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08-10-2019, 07:48 PM	#8
drrust Captain 336 Rep 724 Posts Drives: E90 M3 DCT Sedan Join Date: Jun 2016 Location: Cincinnati iTrader: (0)	I suspect it is the oil cap. If you haven't removed it and put back on you should be able to see oil escaping if someone revs the engine. If you remove the oil cap, try pressing down as you turn. Double check how much is leaking by looking while the someone revs the motor.
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08-10-2019, 07:51 PM	#9
wfdeacon88 Major 1105 Rep 1,389 Posts Drives: E90 M3 Join Date: Sep 2018 Location: Triad, NC iTrader: (0)	Mine was not as dramatic, but my leak was the oil filter housing gasket. no idea if that's the case, but before changing valve cover gaskets, make sure that is checked by the shop.
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08-13-2019, 08:24 AM	#11
bkfastwagon Second Lieutenant 191 Rep 236 Posts Drives: 2011 e90 M3 Join Date: Dec 2017 Location: Boston, MA iTrader: (0)	It was the cap. Replaced with a new one and hasn't leaked so far. Will see. Thanks for the input.
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