Oil cap mod

[F34R]

The crankcase is under vacuum. Leaving the oil cap off opens what is supposed to be a closed system.

He has done over 200kms I think you are wrong. Has anyone tried a sports sock? They are designed for wicking sweat and I think that technology would apply here too.

[5seriesor3]

Why should I buy another oil cap when this method works perfectly?

All these people are saying it's a sealed system and not having a cap ruins that and yet they've provided no sources for proving it

[Matt-B]

so dumb...
oil caps are like 5$ used

[DrJosh]

Care to prove how this is a vacuum leak? I've done lots of research online and not one source has pointed to it being a vacuum leak.

I'll believe my own research over some guy on a forum.

The crankcase is under vacuum. Leaving the oil cap off opens what is supposed to be a closed system.

[Stanley Rockafella]

I also use a sock as a gas cap. Also keeps the fuel vapors from causing too much pressure in the fuel system on hot days.

true story

[5seriesor3]

Thanks. I use a zip tie to keep the sock from falling in. I've done about 200kms with the sock there and no issues.

[djjerme]

Seems legit.

[5seriesor3]

Care to prove how this is a vacuum leak? I've done lots of research online and not one source has pointed to it being a vacuum leak.

I'll believe my own research over some guy on a forum.

[rmdashrf]

im not sure if trolling or not, but that just seems like a huge vacuum leak.

i remember reading a forum post years ago about a guy who lost his "710" cap on his E46 M3. he stuffed a sock on it and it got wrapped around his cam.

Oil leak, id check your oil filter housing gasket (OFHG) and valve cover gasket first on a M54.

[5seriesor3]

Hey everyone

I've been a bit of a lurker for a long time now and only just created my own account because I wanted to share this.

Long story short, I lost my oil cap (stupid I know!) but I didn't have time to go get a new one, so I did some reading online and found out that a business sock can function as an oil cap! Low and behold, I installed the sock where my oil cap goes and the car runs great!



I've been told it actually let's the motor ventilate all the extra gases with the sock on it instead of being sealed by the cap making it run a bit more efficiently and I have noticed a difference. I did this on an E39 and I haven't done it on my e30 yet but I'm pretty sure it will work on any BMW.

On a separate topic, I've found that my e39 has developed some leaks on my garage floor. Does anyone recognise this leak pattern and where it might be coming from?



Thanks everyone. Hope my first post is helpful!