Oil filler cap problem

[NoRRmad]

I went down to the garage today with a bottle of synthetic oil, to add a couple of ounces and get the fill level back up to the center dot on the sight-glass. When I turned the filler cap, it turned past the usual quarter-turn without releasing. It seems that the plastic insert has come loose from the aluminum.

Is there anything I can do?

[owldaddy]

Take the valve cover off and remove cap assembly from the inside.
Don

[NoRRmad]

Thanks, Don! Will it just press out under finger pressure, or do I have to have special tools?

[Sunbeemer]

Sometimes you can stick your finger in the hole and pull it straight up and out if it's not too tight. This sould save you from having to remove your valve cover in the cold! Probably the little locator tab on the neck has rounded off allowing it to spin in the valve cover bore.
Might want to have another filler neck (and a new o-ring since you're there, they're cheap, and they leak!) handy to push back in, or at least stuff a clean rag in the hole to keep dirt out until you get one.
Sorry, the above wouldn't work unless you could get the plug out first...
If you do have to remove your valve cover, it will press out pretty easily from the inside...

[NoRRmad]

Thanks, Rich! Since I seem to need to replace the cap, filler neck and two O-rings, while I'm there, are there any better assemblies, like the "lockable" cap I see in the parts catalog? Anything better aftermarket? What do you recommend? (Gee, I don't remember when last I had to use the question mark so many times in a posting.)

[Sunbeemer]

While I still have the OEM plug and neck, there are many good options available, none of which I have used. But if you're concerned about tampering (sugaring, etc.), then any of these might fit the bill, although none of them, it appears, replaces the filler neck tube:

http://www.ascycles.com/detail.aspx?ID=33528

http://www.ascycles.com/detail.aspx?ID=33528

http://www.wunderlichamerica.com/mm5/me ... gory_Code=

http://www.wunderlichamerica.com/mm5/me ... gory_Code=

http://www.wunderlichamerica.com/mm5/me ... gory_Code=

http://www.wunderlichamerica.com/mm5/me ... gory_Code=

Hope this helps answer your questions.

[rdsmith3]

I have replaced my whole assembly at least twice. Every time, I can just pull out the old plastic sleeve with my finger so I do not have to take the valve cover off. I keep using the BMW parts because they are cheap (for BMW). Two O rings, a cap and the plastic insert are well under $10 IIRC. I just cannot bring myself to buy one of those high priced ones.

[Biff's R]

stop saying that any BMW parts are cheap. They may raise the price.

[challey]

The OEM plastic filler cap is a poor design and a pretty feeble execution. Just like the QDs, this is BMW cost cutting. I replaced mine with this one and haven't had to give worry about a leak or about someone loosening (or taking) the cap:
http://www.moto-techniques.com

A bit pricey but very well made. Yes, you'd have to replace the stock plastic cap a couple of times to get to the price of the Moto Techniques plug but IMO, the peace of mind is worth it. Pretty much the same argument as for replacing the QDs, although an oil filler cap is not likely to completely strand you the way a QD failure would.

Charlie

[rdsmith3]

I have to admit that my cheap plastic BMW assembly does still leak, even with new O rings.

So in my cost analysis for justifying the moto techniques, I should factor in the cost of Mobil 1 synthetic blowing in the wind.

[KiwiRR]

I had exactly the same thing happen to mine with an aftermarket plug. I managed to wiggle/pull the whole plug and sleeve assembly out without taking the valve cover off. The insert is only held in with an o-ring and tab insert to stop it rotating. I popped the same assembly back in and when I remove the oil plug now I just apply downward pressure at the same time to prevent the tab rotating....good luck.

[boxermania]

Most of the time not pushing slightly on the cap will make the whole unit rotate and move upwards on the o-ring allowing for a small amount of seepage. The other ocurrence happens when there is dirt collected between the cap and the o-ring with about the same results.

KiwiRR hit it on the head, a slight force and twist downward will prevent the whole unit from loosening, keeping the cap and the top o-ring clean will help as well.

[OU812]

http://www.ascycles.com/detail.aspx?ID=33528
This is what I went with. Metal "fingers" or "tabs" as you will.