E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > Tuning & Tech > DIY: Do It Yourself

DIY: Do It Yourself
Post here to share or improve your wrench turning skills! All BMW E46 DIY tips, tales, and projects discussed inside. Learn to work on your car and know the right BMW parts you will need!

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-09-2015, 01:46 AM   #1
EuroSlovakiaE46
Registered User
 
Join Date: May 2011
Location: Chicago, IL
Posts: 11
My Ride: Toyota Highlander
Send a message via Skype™ to EuroSlovakiaE46
Oil cap blew off?!

Hello all, I own a E39 525i and we share the same motor M54B25, (most of us know this). I just recently rebuilt the VANOS unit and replaced the valve cover gaskets on my car. I performed an oil change with my buddy and he closed the oil filler when we finished filling the car. I double checked that it was screwed on and proceeded to drive the car the next two days. Long story short, the second day the engine was idling weird and the SES light came on. Lean at banks one and two. I figured that I may have had some type of vacuum leak and I proceeded to drive home after work. As soon as I got back, I opened the hood and the oil filler cap was gone. No where in the engine bay. I am completely baffled by this, and my only thought as to how this may have happened is that the crankcase vent valve is bad, and when I was driving on the highway, the increased crankcase pressure managed to shoot the cap off and disappear under the car. I have bought a new oil filler cap, and crankcase vent valve kit online. Absolutely no oil splattered in the engine bay, everything was dry. Anyone else have an experience of how a cap can just blow off and provide some insight? Thanks
__________________

I need an E46 to replace this Highlander!!
EuroSlovakiaE46 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 08-09-2015, 10:11 AM   #2
markusmarkus
Registered User
 
Join Date: Jul 2008
Location: USA
Posts: 2,413
My Ride: 2001 330Ci
The oil filler cap wasn't properly secured. Period. These caps are way to meaty to be blown off by a bad ccv valve.
markusmarkus is offline   Reply With Quote
Old 08-09-2015, 11:03 AM   #3
EuroSlovakiaE46
Registered User
 
Join Date: May 2011
Location: Chicago, IL
Posts: 11
My Ride: Toyota Highlander
Send a message via Skype™ to EuroSlovakiaE46
I would say the same, but it was. After he closed it, he asked if he did it right and I physically took it off and rescrewed it into position. I'm wondering if the old cap itself was too loose or faulty, because the new cap I bought has a set of plastic tabs along with the metal ones and it holds super tight. I'm just afraid of driving the car because the pressure may find its way out somewhere else, like the dipstick tube, or back out through the new valve cover gaskets.....
EuroSlovakiaE46 is offline   Reply With Quote
Old 08-10-2015, 07:36 AM   #4
markusmarkus
Registered User
 
Join Date: Jul 2008
Location: USA
Posts: 2,413
My Ride: 2001 330Ci
The new cap will be fine. As I wrote above, there's no way that crankcase pressure can be high enough to blow a cap off.
markusmarkus is offline   Reply With Quote
Old 08-11-2015, 05:30 PM   #5
Gus-CO
Registered User
 
Join Date: Apr 2015
Location: Denver
Posts: 73
My Ride: 323ci
Agreed... double checking you and your friend did didn't work. Cap was loose to begin with. No way it would come off by itself, or by excess pressure. For starters, there is only vacuum there unless lots of other stuff go wrong at the same time which is extremely unlikely. Even if there is increased pressure, that cap is not designed to do anything with it.. and will not just blow off.

Last edited by Gus-CO; 08-11-2015 at 05:32 PM.
Gus-CO is offline   Reply With Quote
Reply

Tags
ccv, e39, oil cap

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 07:28 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use