the above video is about excessive crankcase VACUUM...

this thread topic is about crankcase PRESSURE popping dipstick...

aren't vacuum and pressure the opposite ?

> How to deal or prevent crankcase pressure?

 

Mate you arent really helping here. IMO this is highly unlikely to be an actual "blow by" problem this is a PCV valve type issue something is blocked or not opening like it should or busted. Watch the vid below!! The vid I posted above really shows how complicated the system is on these its not like its just a one way valve coming off the valve cover like old engines and there are many components in the system.

It has only popped the dipstick once (have no idea if it just wasnt down properly or whats going on there) but wife just drove the car and the dipstick was still down which proves to me it most likely only happens under hard acceleration which makes sense as your going to get some crankcase pressure doing that it just depends on if the crankcase ventilation system is functioning correctly if thats dodgy or not.



Now heres a video with my actual symptoms. With a stab of the throttle at idle you can hear a huge sucking noise from under the intake manifold or somewhere which I doubt is normal.

Heres the vid:



Interestingly the microphone on my phone seemed to pin point the left rear side of the engine (when sitting in the car) for that huge suck when just stabbing the throttle at idle. But i'l have to try that again and see if I can replicate it and pin point it on that side of the engine...

vaccuum under the cap seemed normalish when I removed the cap but not sure.... id need a gauge like the guy in the video to check it properly it did seem like a fair bit of vacuum there but im not sure whats normal it didnt seem CRAZY excessive.


Now I'll go read the codes on the computer if there are any.

EDIT: No codes on the engine.

EDIT2: just drove the car around the block at a reasonable pace didnt pop the dipstick. The car idles normally about 600rpm totally steady I cant really fault it TBH.


Maybe I overreacted about the popped dipstick we'll see if it does it again guess. But I deff want to understand the PCV system on this engine better. We need to take the car on a long drive out of town this week so that will be a good test for it I guess.

 

> It sounds like your failed PCV is allowing too much intake vaccum into bank-1 valve cover through a poked diaphragm ?


> ​​​​​​The dipstick pops up when the PCV is unable to release enough crankcase blow-by pressure.


> I have another failure mode for this amazing PCV... it blows over a 1-Qt of oil in the intake plenum per oil change. Benz engines prior to M276/8 were famous for breaking plastic plenum rods stuck in sludge.
Combine that with direct injection and you get dirty intake valves disrupting air flow....

 

Perhaps it is worth clearing the vocabulary first

"Blow by" --> https://www.gatestechzone.com/en/new...se-ventilation

All internal combustion engines have "blow by", how much is something else.

PCVs are inserted in the design of an ICE exactly to deal with "blow-by", If the blow-by is excessive, the PCV valve will be overwhelmed anyway.

​​​​​@CaliBenzDriver advice is spot on. and your appreciation for how complex MB PCV system is as well. Please keep us posted on your findings. I have seen the oil dipstick popped 3 times in 80KMi as well. The first time, I thought I did not push it correctly, the 2nd time I blamed the dealer after oil service, and the 3rd time I was convinced something is OFF and monitoring it now (check your oil catch can at the front just before the throttle body), if it has lot of oil start tracing back to the centrifuge in the back. In the M272/M273 it was easier to access it and check, in the M276 is a bit more work (PITA to me).

Now for the video: the "vacuumish sound" is like there is an opening, missing connection in front of the throttle body. To me sounds like when the air-filter is missing, or extremely clogged, does it not?

The idea of a "cable tie" to prevent the dipstick to pop, it is not such a good one. That extra pressure needs relief, close the current exit and it WILL find another one. Would you rather be through the camshafts covers? or even worse through the position sensors, or solenoids as @Left Coast Geek highlighted?

 

The outstanding question is about high crankcase pressure - What can be done in NA & TT engines?

I don't have many hands-on solutions as my dipstick has not popped yet.

I think we can agree that pressure should best be:

• reduced at the source
• vented through a working PCV
• not captured by stronger seals!

As far I can see, the easiest is to reduce the source so that PCV can handle the whole gas flow without creating additional pathways (dipstick, valve cover, sensor leaks, oil cooler,...)

That brings us straight to the 3 piston rings that seal cylinders gases.
- use oil with thicker viscosity
- clean jammed piston rings (Marvel oil/Seefoam??)
- Re-enable piston lube to prevent heat + wear.


​​​​​​@S-Prihadi has clearly shown us first hand how this engine controls oil pressure.
Thank you Master Surya for leading the gang through original discoveries ​​​​​​

The ultimate solution is to have oil on cylinders walls to seal free piston rings.

-- Fancy LM oil viscosity drops down at operating temperature... Try a more stable oil !

-- High blow-by is created by dry pistons that can't seal walls. Re-enable piston sprayers below 3,500.RPM to provide oil to cylinder walls for a dynamic seal....

-- All in all these engines are not so well lubricated in novel ways that create unecessary drama.

Q: how many of you think the high blow-by is caused by poor piston rings seals, worned put cylinders, lack of dynamic oil seal ?

++++ Ah-ha moment ++++
Anyone could say TT WOT boost will blow everything in it it way and it would make sense, right?

however here we are dealing with soccer mum's NA engine driven exclusively below 2500RPM top.
That means low pressure, low output power yet high blow-by... that's when I guessed the disabled cylinders/piston sprayers is the root cause. 🧐

 

I've noticed the same issue with the oil dipstick popping up on my 2012 E550 4matic sedan. It pops up around an inch. I'm hoping it's just an old O-ring, but I found this video from FCP Euro and they go over some of the common issues on the W212 and they specifically talk about the oil dipstick popping up.

They said it could be the O-ring on the dipstick, but a more common cause is the "crankcase breather system." Excess crankcase pressure can cause the oil dipstick to pop up.

 

I had that oil stick problem with a high mileage Volvo 740 turbo wagon under extended high boost, like a fully loaded wagon. Climbing the west side of the sierras at 70 mph for an hour. Plus, I pull over the top of the hill and the engine would be smoking from all the oil. Oil it's sprayed out on the heads and some of it drips onto the exhaust manifold. Far as I know it was a mix of high mileage engine ring blow by, and clogged crankcase breathing systems which on those old Volvo b230 engines was pretty primitive

 

Just to add to the mix,

We have 2 x E350 wagons, 1 has 70,000kms and the other has 90,000klms and every so often I can hear a gurgling/popping noise and the dip stick has been ejected just like everyone else on here....both cars have zero oil consumption issues (touch wood) neither blow smoke or do anything strange engine wise.

I suppose a leak down/compression test would be the only way to prove blow-by possibility?

See what readings you get across all cylinders to maybe pin point a possible low cylinder.

Cheers!

 

FYI mine hasnt popped again so im assuming in my case I didnt have the dipstick seated down right.

Otherwise I think dipstick O ring and the pcv system are most likely culprits.

Unless your seeing other associated problems like the car actually smoking or running bad and oil consumption id be very leary about assuming its a blowby issue. I reckon that is chasing your tail stuff.

 

I feel the same way to be honest, I've owned so many shítbox cars growing up and know first hand when a motor is on its way out and Benzs aren't junk makers like so many other marques. I'll change the O rings and see how it goes, it doesn't spew out oil or smell so it's not a massive issue either just a nuisance noise wise when idling as I always warm up my cars before driving in the mornings and it's really noticeable.

 

I replace the dipstick tube o-ring every oil change. New o-ring comes with the Mann oil filter, it's the smallest one in the package.




I usually get them from eEuroparts for a good price. And if you sign up for there Loyalty program you get a $10 credit to use on anything plus get points for every dollar spent to use on later orders.

https://eeuroparts.com/?wlpr_ref=eEuro_atc0xpy6j

 

That’s what the other ring is for! I always just figured it was used on other engines for something else. Three are used for the oil filter canister…what’s the fifth one for?

 

For my Mercedes W204 Mann HU718/5x filter:

largest o-ring is for the oil cover/cap.

The 2 that are the same are for the shaft the filter slides on.

The smallest is for the dip stick.

*For the 5th o-ring I read in a Chrysler Crossfire thread that uses the same filter that if you unscrew the cap from the shaft there is an o-ring there. The shaft assembly looks different from my Mercedes M272 oil filter assembly though, they use the o-rings differently it looks.

 

Just came across a Mercedes W208 thread where they talk about the o-rings. Even there oil filter assembly looks different than my W204.



Here's the thread where i got the photo from. https://mbworld.org/forums/clk-class...il-filter.html

Appears the Mann HU718/5x filter is used in a few different versions. Probably why the only instruction included shows the o-ring on the cap, since thats the only similar spot on them.

 

2014 w212 e350. I’m just here to reconfirm that replacing the o ring worked for me. It clearly is now snug going in… so it’s snug to get out and doesn’t.

OE part Numbers

A0229977545, 0229977545, 022997754564

 

i drive a 2010 s550 and i recently checked my oil after being prompted to on the dash, it was basically nothing left. so i add 5 quarts of oil keep in mind this car takes 9. so i drive the car a bit and not gonna lie i push this car alot, theres just a ton of smoke coming from the hood. the dipstick is popped out and theres oil all over the trans i can see. i dont know if it came out from where the dipstick goes or what? but it was everywhere down there. and now it wont stay in and i just assumed okay maybe i didnt push it in all the way. i push it in and im flying down the road prob going 100, and a giant ****ing smoke bomb goes off in the engine bay and it looks like my car ****ing blew up and was about to explode at any second, everyone behind me prob thought my car was ****ing on fire. i pull over dipstick is not popped in, i check the oil level and it was PAST max??? which doesnt make sense because i only added 5 quarts and it was basically on empty. now theres 2 possibilites, i misread how much oil WAS in the car and added way to much or something else. but because the car was promting to check oil, and i checked my self and saw basically no oil im gonna assume i didnt overfill it but i have no ****ing clue what happened and how its showing past max on the oil dipstick. honestly i prob ****ed something now. because the oil dipstick wont stay in and im noticing the oil is disappearing and going below max now. i hate mercedes their cars are gay

 

The first pull is likely dry because of the airtight seal always do a second pull. As for how to check, this thread might help.https://mbworld.org/forums/e-class-w...-dipstick.html

 

Yes, I was going to say always check the oil level a few times to be sure. When I check my oil the dipstick is always dry the first time removing it. Stick it back in, count to 3 then remove it again to check.

Not sure with your specific engine/dipstick but in my Operators Manual in the glove box it tells you exactly how to check it. It also states that from the Min-Max markings on the dipstick it is 2 quarts of oil. You want the oil level right in the middle.

So in my case if its reading at the Min marking add 1 quart of oil. If its at the Max marking that is ok, but if its over then oil should be removed, siphon some out the dipstick tube.

 

Of course the dipstick is popping out due to all the extra oil filling blocking and contaminating the breather system. Sounds like you dont know how to properly check the oil or refill the oil and now youve overfilled your engine...maybe that has less to do with the sexuality of the brand and more with owner ignorance and lack of educated maintenance choices. Time to do a proper oil change before you drive it. Drain it from the bottom while it's warm and let it drip for a half hour. Im suggesting a long drip time since you will have oil dripping from non normal areas. Make sure the oil filter is new and the cap is working properly. Then add in only the exact amount needed per the manual and not the dipstick. Then run the engine till warm, and then let it sit for five minutes before checking the level. Id suggest not driving the car a hundred miles an hour while you have this issue as thats a good way to go shopping for a new vehicle. If you really found your car with five quarts down, your first thought should not have been to fill it up and drive it but to find the leak. The car is going to smoke until the upper end breathers clear out but you could also pull the whole vacuum system and clean it with a solvent so all that oil film doesn't attract dust and dirt. Good luck.