Routing excess oil separator out of engine bay
 

Hey guys,


I bought this intake kit:

Mercedes Diesel Performance Air Intake Kit 300D | eBay

Probably way overpriced, probably could've made a DIY one for way less, but I really like it and it looks great in the engine bay, also gives the turbo a sweet sound.

The shorter, upper separator gets the actual oil to the oil return line and the blow by to the longer tube. The longer collector vents the blow by out and collects any oil that makes it out. The collector just vents out into a long hose which you just kind of tuck under the battery tray into the back of the engine bay.

Great design IMO, but I have one of those engines that despite having terrific signs of life, just has a bit more blow by than it should. I've learned not to worry, but the tube just vents it out into the engine bay and makes my engine bay kinda smoky when the car is running.

Not a huge deal, but something I'd like to maybe resolve. I had an idea of going down the exhaust, and drilling a hole in the mid-pipe region, and getting a little threaded tube fitting, then just mounting a longer hose to the collector and running the hose to the fitting on the exhaust. This would just vent the blow by into the exhaust and out the back of the car.

Is this a good idea? As in, would I have to worry about the exhaust trying to push its way up the tube and into the collector, thus creating pressure in the whole system? Or do you think the exhaust would flow by it and let the blow by just flow in with it?

that blowbye really needs to go back into the intake. you could drill and tap that metal elbow and install a hose barb, or use one of these on your silicone reducer: http://www.siliconeintakes.com/product_info.php?cPath=12&products_id=500&osCsid=70b92d508f5fa389a2206159c3f5c625

did you see my version? time to pimp my thread...

http://www.peachparts.com/shopforum/diesel-discussion/327970-catch-can-cold-hot-air-intake-how.html

Drill a hole in the tube right after the air filter and route the blowby back into the turbo. That's what MB did on the early 617's in the 116 chassis.

By the way, I don't get the point of that kit. I see no advantage over the OE setup.

The advantage is purely on the seller side of the equation. :D

Ugh. another member lowering the performance of his vehicle to gain turbo whine and poorly filtered air to the engine.

lets see some pics of it installed on your car.

you understand the stock air filter flows MORE air than the car can possibly use right? I understand that the rattling broken mount is SUPREMELY annoying, and hearing that turbo whine is appealing to say the least, but it will get annoying after time, and the foam/oil filters really cannot filter the volume of air a diesel ingests!
I would route the smokey air back into the intake as pgirngo suggests. I'd also change that filter to at least a paper element, and install a heat shield to surround it, and get a fresh air intake routed into the box.

one advantage is "what you don't see."

s p a c e

via removal of the stock monstrosity.

You're probably right. The only thing I liked about it was that the oil separator seems a lot more effective than the original. Maybe mine wasn't functioning properly. I don't know. But I enjoy it well enough.

I will trust the technical aspect of your post and look ino those parts. That makes enough sense. Albeit, I haven't noticed any decrease in performance, if anything, the engine seems to breath better at higher revs. But I trust that you're one of the members on here who knows what they're talking about.

As for your opinionated prediction on how you think I will feel about something on my own car, thank you, but no thank you.
This is it. Among other things, it frees up a lot of space. I was just looking for an idea of what to do with the excess air. I suspected filtering back into the intake, but wasn't sure. I have my answer now. Thanks guys!

vstech knows his stuff for sure. The bracket isnt really a huge problem. The best solution is to just weld in additional metal. Did that on both 300SD's, not a problem since.

Frees up a lot of space to do what though?

You`re young, go for it, but in the end when you get through spinning your wheels trying to modify everything. you will just drive them and enjoy them. other things will take up your time.

wife, kids, working, paying bills/taxes, rent. house payment, trying to survive, paying off the ex/alamony, (all the money) child support. :D

Yeah VSTECH knows what he is talking about for sure.

Charlie

clean grime. access wiring/sensors. adjust mbc. visual inspection.

You're so right. Cant wait to be spinning my wheels in my 120hp Mercedes! Did you ever stop to think maybe this is how I enjoy my car? You enjoy yours differently. Luckily, I do not have all of those things to worry about yet. Hopefully I wont have half of them. Going to try and make good decisions in my life.

Yep. I really just mainly enjoy how it looks in the engine bay over all.

Young bucks...

What is the problem here? I asked a simple question and it always turns into this condescending argument.

It's clearly a bargain at any price

Can the mods close this thread? I have my answer for the tech aspect of the question. Anything else from here would only be needless banter.

I think its just the question in particular that you asked. Its been asked before and lots of folks who've been down this path multiple times.

Its generally understood around here that stock air box = better than those attach on cone ones as they just end up sucking under-the-hood air which is normally warmer than the outside air.

Its your car and you are free to modify it to your hearts content and I support modifications. Most of my cars are modified to a degree or another.

Charlie's right though life does eventually get in the way of playing with cars. So do things while you have the time!

My only advice is that you change/clean that filter often and that you avoid K&N filters for the diesel's sake. I understand that they allow more air in but they sacrifice filtration to do so.

Good decissions are the one`s you make later after you have learned from all your bad decissions that looked like good one`s at the time.

we have all made them and done them, and if we had listened to our parents or other people that have gone before us, in a lot of ways it could have save us some frustrations in life.

Do I listen, heck no, I have to try things also that some one told me would do such and such a would do so and so. some day I`ll wise up too, better hurry up pretty quick, 69 is getting close. :eek:

Enjoy your car, and have fun with it iam not criticizing you, don`t take it that way.

One thing you can do with the K&N style filters is buy some batting. they sell it at the yardage stores by the yard. make a cover over the filter and then spray it with the K&N oil. it would be a prefilter, then change it and wash or make a new one. hot glue the edges together and it would be like a sock.


Charlie

I do like the looks of the engine bay with the non-OE filter. Seeing the turbo is pleasing.

I get that. And I definitely know one day the car will be low on my priorities. Well, lower. I already do quite a lot. And there will only be more to do as time goes on. haha

Yeah, I avoid K&N Filters like the plauge. Although, this one may not be too far off. I will probably look into a paper cone filter like vstech recommended.

I gotcha now. Sorry for how I reacted. I do hope you get to have your fun with your car as much as possible, other circumstances allowing. haha

Interesting idea on the K&N filter sock, I definitely might look into that. Thanks!
Same here. I just think it looks nice. Cleans up the engine bay, makes a lot of things much more accesible, and just looks cool over all. I do suppose it's not for everyone, but then again, neither is the stock assembly.

I feel like the "warm" air difference is so negligible that as long as you use a good filter, a DIY intake is better in every way.

I'm still deciding how I'm gonna collect that nasty, oily blowby. I don't like the idea of it going right back into my intake elbow and making a mess of the elbow and the turbo impellor like the stock setup.

Also, what did everyone do with the drain tube back down to the pan?

I suppose you could always take advantage of the tube since its there. Just route your blow by down it.

does not compute. turbo_whine=pure_sex

If the temp differential was actually negligible, MB and every other manufacturer wouldn't have made every effort to draw their intake air from outside the engine compartment. MB even made their own specially vented fenders for most 124 diesel engines exactly for this purpose.

As for a catch can, I soldered in a nipple onto the turbo oil drain in order to re-route the captured oil back into the pan. I used a good old fashioned 240D catch can. Try this for a sleek alternative

I was reading about diverting some of the blow by oil into a cannister and then read that the the stock air box has kind of a turbo separator that spins the oil out and puts it back into the crankcase. Sounded like a good idea.

and they put the air filter assembly right smack dab on top of the turbo which can get so hot that it glows red & white, but oh, that's not heating the intake air. *rolleyes*

If your 617 turbo is glowing red (or white), you have a problem.

I'm hardly a fan of the federal air cleaner assembly for a variety of reasons, but if you're going to make a modification to any given system, I advocate a "do no harm" approach as a first order of business. At least the MB system attempts to draw cool air into the intake stream. Those expensive ebay hot air systems just remove the cool air stream altogether and promote the intake of heat for the sake of style--> function follows form. The Cal-spec intake systems do an excellent job of setting the air cleaner aside and gathering cool air...too bad the cleaner element is so bloody expensive.

might need a bigger turbo.

fixed.

... editing words into someone's quoted text is against the rules... I'll FIX your fix...

can you explain how a bigger turbo would lower egt's ?

I'm no turbo expert, but I thought more power made heat...

unless you mean that a turbo spooling differently or fueling differently would lower egt's

I know that overfueling will cause more heat, so adding extra air to existing fuel could lower temps...
explain your reasoning please, thanks!

wowe wowe wowe. it was a more "scarface" state of mind response as in "first you get the money, then you get the power, then you get the women." do you not get it? run small turbo hard to limits...get bigger turbo. run bigger turbo hard to limits...get holset. YES! and yes there are lots and lots and lots of assumptions in there as to tuning and $ spent to get there.

i guess i had better stop having so much fun and being in a silly mood. i feel like i've stumbled into an old AOL message board or something.



this might be the only place in internetz that's not down with ftfy.

Guys are always trying to make the point that the stock design is so great and doesn't need changing because it draws a small charge air from in front of the radiator and already flows more air than the engine could ever possibly use without different manifolds and porting the head. That's all good and fine, but the stock assembly is a needlessly gargantuan POS that rattles around like a bag of pots and pans, and self destructs far too often for my liking. It sucks nasty oil all over the inside of the housing making a huge mess (when it's not leaking all over the rest of the place), and consequently makes any servicing of the intake very unappealing to me. The fact that the steel housing for the filter sits on top of a very heat centric location on the engine and does in fact get hot itself does kinda defeat a bit of the "cold air intake" argument. The fact is though - these aren't high performance (and are bad platform for making high HP at that) cars and as long as comparable filters are used - probably will be effected very little in engine life and performance by a change between systems at this point in their life cycle. These things are 30 years old by now and I don't think there's too many daily drivers that will live to the point where it would have noticeable adverse effect on either measurement.

The system I have now is compact and effective. It draws air from right where the mouth of the collector in front of the rad exits. It's simple to inspect, service, and replace. It doesn't use the stock crankcase vent or drain that always seems to leak, but I haven't put in any solutions. Thanks for that link, btw.