[N55lif3]

Just had all the gaskets that were leaking on the car changed. Valve cover, oil filter housing, and oil pan.

Now I’m still noticing an oil leak and I’m losing a quarter of oil on the gauge every 3-5 days. Doesn’t leak when I’m not driving it.

Can anyone tell me if maybe the oil pan wasn’t tightened or gasket was pinched based on my bad photos? I know the rear main seal rarely leaks so if it actually is then I will officially declare that I have the worst luck on this forum.

There is oil on an oil pan bolt so I was getting some hope. Also took a photo of just under the tranny

[tlow98]

Sounds like something other than a gasket to me. PCV valve maybe?

[TunafishE93]

The color looks a little red but might just be the pic, you sure some of that's not tranny fluid.. I am assuming that by gauge you mean on board computer. That is quite a leak going thru a quart in 4 days, it should be easy to trace.. Some thoughts if it doesn't leak all the time its not your oil pan gaskets.. This tells me something under pressure, oil cooling lines, but main seal is under pressure also...

[Silnismo]

Same issue here, after replacing all the common oil leaks come to find out it was the rear main seal. Way more common then you think.

[NGEE]

Originally Posted by Silnismo

Same issue here, after replacing all the common oil leaks come to find out it was the rear main seal. Way more common then you think.

Did you have it replaced? What did you pay?

[marvinstockman]

If you were leaking a quart of oil every 4 days or so, the car and the ground below the car would be covered in oil.

If I had to guess, the engine is using the oil. Before you spend money fixing leaks, fix the engine.

[mweisdorfer]

If.......

1) the oil pan gasket was done correctly.

2) you know for sure that oil isn't leaking from the firewall side of the valve cover gasket (where you can't see it unless you use a telescopic mirror),

3) and the PCV valve & hose/ valve are working correctly and have been changed in the last 50,000 miles..

THEN you can say it's most likely the Rear Main Seal.

This will require you to take the transmission out of the car. There is a good diy video on how to do this on YouTube.

I'd stay away from BMW sealant. It's a Major PITA to inject and use & it's VERY EXPENSIVE. You are way better off with Ultra Grey and letting it cure for 24 hours. At least That's been my experience with the front crank seal.

[mweisdorfer]

Originally Posted by TunafishE93

The color looks a little red but might just be the pic, you sure some of that's not tranny fluid.. I am assuming that by gauge you mean on board computer. That is quite a leak going thru a quart in 4 days, it should be easy to trace.. Some thoughts if it doesn't leak all the time its not your oil pan gaskets.. This tells me something under pressure, oil cooling lines, but main seal is under pressure also...

Good call..

The OP should look at the megatronic seal on the tranny. Those tend to leak

[Sgop335]

Originally Posted by NGEE

Did you have it replaced? What did you pay?

I had the rms replaced on my 335i by Revolution motor works, $1100 or so.

[Silnismo]

Originally Posted by NGEE

Did you have it replaced? What did you pay?

It is not leaking much, maybe a quart every 6 weeks or so I just top it off until I can address permanently down the line.

[lowrydr310]

Originally Posted by marvinstockman

If you were leaking a quart of oil every 4 days or so, the car and the ground below the car would be covered in oil.

If I had to guess, the engine is using the oil. Before you spend money fixing leaks, fix the engine.

I've been wondering about this myself. I have to add a quart every 1500-2000 miles, mostly stop and go city driving so lots of engine runtime. I have zero smoke out the tail pipe, even at startup. Absolutely nothing. I even let someone else drive my car while I rode behind it on my motorcycle, and even on the hardest acceleration or deceleration I cannot see or smell any oil burning.

My oil pan and the front of my engine are wet with oil, from what I'm guessing is a leaking oil pan gasket, leaking rear main seal, and slightly leaking front crank seal. The thing is that there are no drips on my garage floor or anywhere I park my car. Is it possible that the oil is dripping from the pan/RMS/crank seal only while driving? I've been driving with my undertray removed so there is nowhere for it to accumulate.

[TunafishE93]

Well for a none leaking engine its within specs to use up to 2 quarts per 1500 miles.. This makes me think its not burning oil.. Still think your leak is not oil pan cause that would leak all the time.. Its also hard to trace oil trails with bottom cover off, oil gets blown all over.

[N55lif3]

Checked firewall side of valve cover and it looks clean and the engine block looks dry and clean as well.

I’m not sure how to check my PCV? My engine makes no unusual noises. And how would it leak? My vent hose was replaced recently.

Shop who did my gaskets are now saying rms but gonna hold it off for now and bring it to some more shops for their opinions

[N55lif3]

Also the car is leaving a lot of puddles and is indeed leaking. Going to just leave the car running on a lift and see for myself because I’m in doubt

[TunafishE93]

You can pull the hose off the PVC valve and while running it should not suck a lighter flame in.. If it does valve is bad..

[NGEE]

Originally Posted by TunafishE93

You can pull the hose off the PVC valve and while running it should not suck a lighter flame in.. If it does valve is bad..

Is that photo an N55? I don't recognize where that is. Under car or behind valve cover?

[nsjames]

first step to finding an oil leak.

clean the whole damned thing.
thoroughly.

it doesn't go up, so the highest place you find oil after running the engine for 15 minutes in park is where your oil leak is coming from.

if you still can't find it.
UV dye.

and the PCV causes oil loss, but by allowing it to be sucked out of the valve cover and into the intake. It will not produce a visible leak, but can cause oil loss.
If this is the case the bottom of your intake manifold will be full of oil.

[NGEE]

Originally Posted by nsjames

first step to finding an oil leak...the highest place you find oil after running the engine for 15 minutes in park is where your oil leak is coming from

Makes sense. Oil is weeping from the lowest point of where the transmission joins to the block. Found the leak, still don't know where it's coming from.

Could be bad oil-pan gasket install, could be RMS, could be tranny fluid disguised as oil.

I'm having this issue also. Block - clean. Oil pan - clean.

[nsjames]

then you haven't found the leak.
is it coming from above the transmission and simply weeping down the interface at the block/bellhousing?

clean the back of the engine and look iback there with a lighted inspection mirror.

I'd bet you find the back of the valve cover gasket is leaking.
it tends to go straight down the block, then it hits the bellhousing.

[NGEE]

Originally Posted by nsjames

then you haven't found the leak.
is it coming from above the transmission and simply weeping down the interface at the block/bellhousing?

clean the back of the engine and look iback there with a lighted inspection mirror.

I'd bet you find the back of the valve cover gasket is leaking.
it tends to go straight down the block, then it hits the bellhousing.

lol

[iqraceworks]

I have a similar leak coming from my N54 with 6AT transmission. I pulled that rubber inspection port cover right under the torque convertor to see if it was the main seal leaking....but you can't see anything at all, even with a borescope.

Is there any way to know for sure that the rear main is leaking? Or do you have to pull the transmission just to see?

[TunafishE93]

Yes that is a N55 PCV you should easy recognize it since you been poking around the engine.. Its right on top of the VC.. Likely not your oil problem as mentioned above but still good to test.. I stole this pic..