Hi all,

Great forum. I've been lurking, searching, and learning a great deal about the '84 300SD I've inherited from my Dad. I love this damned car, and I want to do everything I can (within reason) to keep her happy.

Anyway, I'd popped the hood the other day, and noticed my breather hose was busted. Real bad. I don't know much at all about these cars, so if someone could be so kind..could I get a primer on this part? What's it for, and how important is it for performance?

My engine works fantastic, and I don't have any noticeable oil pressure problems or anything. My only real issues with this car are failing electronics and panel lights, but I suppose that could be a fuse problem.

Any insight will be appreciated, regarding the breather hose. I also noticed that thing isn't secure at ALL, and seems to slip around a lot. Is there a way to clamp the ends around the openings on either end?

note: when I went in for an oil/fluid change the other day, they said my air filter was "unbelievably oily" and showed it to me--it was coated in oil. Could this be caused by the faulty hose?

thanks for reading

Welcome to the forum.

That plastic tube routes the blowby gases from the crankcase and valve cover back to the air filter housing. Some of the oil in the blowby gas then falls out of the airstream via the cyclone drain in the air filter. The remainder goes to the turbo for burning in the cylinders.

A crack in this tube has no effect on performance. In fact, you could remove the tube completely. But, all the blowby gas would head off into the atmosphere and some oil would be leaking all over your engine.

You can get a new tube from the dealer. There is a rubber grommet at the air cleaner end that can also be replaced.

Start reading some of the posts in the archives. An oil and filter change is one of the most basic things you can accomplish yourself.
Then, you won't be at the mercy of the mechanic who decides which oil and which filter to put in.

You do know what he put in, don't you?

Hey, thanks for responding, Brian.

Oil and filters..yep, I *do* plan on doing that myself in the future. this is my first car, so it's been a great learning experience so far. And man, there's something loveable about an old mercedes! I get a lot of compliments on this car, and I just love driving it. My goal is to get at least 30 mpg on the freeway---right now I'm hovering in the mid/late 20's, so i think I'm good. I keep the tires filled, fluids changed, and try to keep additive in there at all times, if that helps.

I'll be ordering a new hose anyway, from MercedesShop. I don't like seeing oil all over the engine, which IS happening, since you mentioned it!

thanks again

I would recommend the flat, one-piece breather hose.

I'm getting this one, since it looks the most like the one I had before:

http://www.**************.com/store/item.php?item=Turbo%20Diesel%20Breather%20Upgrade

That's the one.

I had this problem when I first got my 300D...this is one of the easier fixes I've had to do, literally five minutes. Stops that optional "external lubrication" of the engine from the droplets of oil that spray out of the crack in the hose. (Then, you can clean the engine and find where the real leaks are...)

__________________
1981 300D, "a lot of" miles (broken odo)
"Engineered like no other 24-year-old beater in the world."