(This is an idea I've been kicking around for around 20 years - don't know whether it's been done, or could be done )
Letting the oil filler cap off the engine to let steam out seems to mitigate mayo buildup, but it's a ball-ache to go under the bonnet every time I park up. Thus, I was thinking about some kind of vacuum- or 12 V solenoid valve installed in the filler cap - closed with the engine running, open when not. It could be held shut by mainfold vacuum (via a 3.5 or 7mm line from the plugged ports) or, if a solenoid, connected to the ignitionsystem terminals.
I know this is a completely crazy and unnecessary idea, but I'm curious whether or not it will work... thoughts? 😁.
ETA - something like this:
a normally-closed 12 V valve that would open when the engine is running. The filler cap would be drilled and a suitable fitting pushed through and screwed onto the back, then sealed up.
Well, I suppose...
Many of those valves are 'pilot' valves that use a small solenoid to open or close a tiny
port that then lets the working fluid displace a larger rubber diaphragm. So they only
work for fluids under some amount of pressure.
If you wanted to go truly science on it, you'd find a way to hook up the intake of the
SAP to draw vapor out of the engine on shutdown. Then maybe have a small nitrogen tank set to
purge the crankcase, just for good measure.
Personally, living in a wet environment and often driving short distances,
I just make sure that no car (we have several, because they're BMWs and break down)
does exclusively short trips to town and back.
BaliDawg Quoted,
"Get the engine up to full operating temperature. Make sure your thermostat is not soft failing."
That's it, just drive the car. Only cost is extra fuel. You must be taking short trips. You won't have condensation if you just drive the car regularly and for more than 20mins.
What is your ambient temp in winter and all year round?
The idea is good, but don't use vaccuum to control -- too messy. Use 12v, like the cabin heater valve controlled by 12v. Maybe get a junkyard heater valve and try out.
The idea is not only to get the engine up to temperature, but to sustain it for a little while.
THEN the water vapor boils off. No water vapor = no mayo.
Provided the rest of the CCV system is functioning properly?
Not necessarily - it can also be caused by moisture buildup from short journeys; if the car is not run long enough to boil it off, the normal moisture present in the engine mixes with the oil vapours inside the valve cover.
= mayo.
A blown HG is usually accompanied by one or more of the following:
dense, sweet-smelling smoke from the exhaust,
over-pressuring cooling system,
loss of coolant,
loss of power,
difficulty starting.
In my experience, a long-ish drive will burn off the "mayo" under the oil cap. For example, it's an hour drive to my favorite race track. Every time I go to the track, the mayo buildup goes away. Then it comes back, after some short-hop driving.
So, the engine is off, the valve is open, steam exits. Then it sits and cools, with the open valve allowing in new moisture out of the air.... If you live in a humid environment you are likely to add more moisture then you let out... Just my two cents. Now if you could have the valve open for a time then close, you might have something. But in the end, if you drive the car more and push it a litte, like they like to be pushed, you may just get rid of the mayo in the process.
again nature of the beast,,they all do it in cold climate on short trips
when ya park remove the oil cap if it bothers ya and you won't
have your mayo on it.....
Looking for a solution that really isn't an issue?
I've been guilty of such at times.
Letting off the cap at the end of a drive is a novel approach. As long as you never forget the cap even once on starting/drive away?
It could help mitigate any trapped moisture in the engine (block/head) itself. However I really very much doubt it would have any positive direct effect to mitigate any mayo trapped in the CCV system and it's associated plumbing. It's NOT a direct path of the vapors in there to the valve cover, other than the hose off of the nose of the VC.
There's a reason BMW updated the CCV system with the foam insulation:
Drive the car, the vapor inside the engine naturally gets very hot. When shutting down, there's a cooling off. Under many (not all) circumstances the un-insulated system will cool off much quicker than the newer version. During such there may be trapped vapors/sludge that cools too quickly and does not have a chance to drip down and drain back to the pan.
Over and over again this happens, creating a buildup. Then issues start to surface. That goo will condense down and create blockages.
Hence why we always clean and/or replace the double wall oil dipstick AND install the insulated version. It helps fend off Dr. Mayo. Is the insulated version a solution? Well no, but it does help.
In a perfect world (where many of the powertrain engineers live 😕 ((Sory Hani)) ) the engine oil would always get hot and the CCV system would take care of itself. However in reality many of us are beset with short tripping as a consequence of our proximity to work and the grocery stores.
Now ALL cars are required to maintain a completely closed crankcase and accompanying CCV system of some sort. Some mfr's do it better than others. Just remember the M54 engine was relatively early in the closed crankcase/CCV system design. Even BMW has improved the system with subsequent engine models, albeit not as much as others.
Despite the Germans selling more cars in the USA, they sometimes forget the real dynamics of a USA driving profile VS: that of the Autobahn commute....
In the N54/N55 tuning scene there are sellers of a breather oil fill cap that has a filter on the top, and usually a metal ball that sits and creates a seal under normal running conditions, but is able to vent excess crankcase pressure during high boost applications, but perhaps you could use this to accomplish your goal.
VTT BMW Billet One Way Crankcase Breather VTT is happy to introduce the first and only available plug-and-play crankcase breather kits for ALL BMW applications that use the two-prong oil tab style oil fill caps. With this breather simply remove your oil cap, install the breather, and instantly...
vargasturbo.com
This is the first one that popped up on google but you can most definitely find one for much cheaper, note i've never used one before.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
E46 Fanatics Forum
17.9M posts
592.5K members
Since 2001
A forum community dedicated to BMW E46, E90, and F30 owners and enthusiasts. Come join the discussion about M performance, turbo kits, engine swaps, builds, modifications, classifieds, troubleshooting, maintenance, and more!