Oil Dip Stick Keeps Popping Up




Ray
Last edited by a4ncar; Nov 16, 2019 at 03:36 PM.




Than you can always make easy blowby test
On stopped engine, remove oil fill cap and put a napkin over it. Start the engine and observe if the napkin stays.
When napkin gets blown away, put a cardboard on the hole and observe if it stays.
When cardboard gets blown away, start looking of new car.




Ray
I never knew this cold happen, how do I check if anything is clogged? I will try the cardboard test and see if I need a new car lol 😂




At least not for last 50 years. Even W123 diesel had complicated drainage system that would separate the oil and dump it back to the pan.
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If the o-rings on the dipstick have shrunk due to age, I could see the dipstick working itself out over time from vibrations. I want to say mine works itself up a few mm over time too so mine probably needs attention as well. One could probably just source new o-rings instead of buying a whole new dipstick. If you were feeling like a champion, you could pull an o-ring off your new dipstick and measure the diameter as well as how thick it is and post it here for posterity





If you have a Harbor Freight nearby, or an Ace Hardware, you can buy single o-rings, or sets for little money. I'd be tempted to measure the old o-ring or take it with you to the store, and try a slightly larger one (metric or Imperial), to see if it seats more securely. For the price of an o-ring (10-15¢) you can experiment. It would be silly to buy a new dipstick just to solve an o-ring problem.
I buy o-rings all the time for my Air Rifles that work on compressed air. Here in Dallas I buy from H&D Distributors (214) 351-1251. They ship all around the country... http://www.hddistributors.com/ Or you can shop the o-ring store... https://www.theoringstore.com/
Last edited by DFWdude; Nov 18, 2019 at 09:43 PM.
Haven't found a solution yet. Started doing it recently.




An easy way to see if that is the case would be to lower oil level as it should be very safe to operate with level at half way between low and high.
Another way would actually be to remove the O-ring so the pressure can get out without popping the stick out.
Then, of course, if the O-ring can be changed an O-ring could be used that is so tight the small air pressure in the tube cannot pop it out.
I'm saying this as the crank case should be under small vacuum when the engine runs and there should be no force to press the dip stick up from its place and the only place such force could build-up is the dip stick tube itself if the bottom end of it is sealed, what a high oil level would do.




Last edited by a4ncar; Jan 15, 2020 at 12:43 AM.









When most o-rings get exposed to other petroleum products, they will "entrain" (absorb) some of the oil through pores in the surface of the oring, or most typically through the spot where the o-ring is cut from the casting sprue during manufacture. Especially true with Buna rubber o-rings.
This makes the o-ring swell, which may be the reason the dipstick rises in the tube... The rubber swells and pushes the stick up. But if contained within the dipstick tube, the oring will just get brittle over time. In short, it may seem like stiff plastic, but it isn't. It's a type of synthetic rubber, just like mine is. Try to pick it out of its place on the old stick with an ice pick, and it should break into several pieces without much prying.
This is a good reminder for all of us, though, to use a rag to clean any oil from the dipstick o-ring before each reinsertion in the tube. Just a swipe is enough.
I hope you didn't spend a lot of money on that new dipstick. I can all but guarantee you don't need it.
Last edited by DFWdude; Jan 15, 2020 at 12:42 PM.
Any thoughts?
I am experiencing this phenomenon recently too. My dipstick o-ring is hard and unusually flat on the contact surface. I suspect that a new dipstick o-ring is more round.
Here is the part number for M276 engine dipstick 276-010-18-72





As for rising 3-4 inches, I'm not convinced there is that much clearance under my hood.
As for rising 3-4 inches, I'm not convinced there is that much clearance under my hood.
As was stated by other posters you may be getting to much blow by , which means piston rings.
Sorry for your problems.
Ray


