Exhaust in cabin- Universal m35

[Georgerobert]

I now have exhaust in cabin. Discovered it comes through 1/4 " tube attached to top of engine. Probably valve cover. There is a copper fitting in the tube. It is disconnected from something but nothing obvious. Should exhaust come out there? Where should it connect to ?

[Spot]

Ahoy and welcome to CF GR!

Perhaps a picture of your situation would help.
Here is someone else's situation:
https://www.catalina36.org/forum/tec...-breather-hose

[skipperpete]

If its coming from the valve cover it’s the crankcase breather and would normally be connected to the intake manifold (or a “catch can” but rarely on boats). If it is the crankcase vent hose it sounds like you have too much “blow by” and may need to find out why.
It could also be coming from the exhaust vent loop anti siphon hose.
If the raw water flow is minimal its a possibility.

[Georgerobert]

Excellent. Will take a pic when back on boat. I do see what I am talking about in the pic. The black hose going to air intake. But I do not think there is a fitting on the air intake like the one I see in pic.

[cal40john]

Originally Posted by Georgerobert

Excellent. Will take a pic when back on boat. I do see what I am talking about in the pic. The black hose going to air intake. But I do not think there is a fitting on the air intake like the one I see in pic.

Some older boats just have the hose placed in front of the intake.

[Boatwright]

It's the crankcase breather system on top of the valve cover. The rubber hose you see arcing over the top of everything is connected to your intake air filter housing (the round cookie tin shaped thing on the port side). The other end should be connected to the crankcase breather. The hose is there to conduct crankcase fumes into the intake where they will be burned up inside the engine instead of stinking up the air.

Fumes coming from the crankcase can smell like exhaust, but you shouldn't see a lot of smoke coming out (a small amount can be normal). If you do you could have badly worn rings. If your engine looks clean and fairly new and unless it has been abused (low oil or bad overheating) it is unlikely that a diesel which can run for several thousand hours before it needs them renewed has bad rings.

Is it possible that the exhaust is coming from the hose at the valve cover end? If so you could have a stuck or badly worn intake valve.

You should first make sure that the hose is connected where it should. You may find you don't have a problem at all.

[George_SD]

I've recently dealt with exhaust in the cabin, but it sounds like it is different from your situation.

My situation was: two pipes going into engine compartment - fresh air intake and exhaust (hot air, fumes, etc) with the fan on it. Well, someone installed the fan to blow in the wrong direction, so it was pushing fresh air into the engine compartment, which then was spreading hot air with some minor diesel fumes into the living quarters. I flipped the fan around and now it's taking hot air out and pulling fresh through the intake as it should.

[Stu Jackson]

When I saw the title before I read the OP, I said, "Exhaust riser or breather hose."


Breather Hose 101 (w/ K&N Filter Pictures from Rick Allen)

http://c34.org/bbs/index.php/topic,8....html#msg63915

and Noah's: http://c34.org/bbs/index.php/topic,8....html#msg64297

and Kloeber's PDF and wiki link: https://c34.org/bbs/index.php/topic,8136.0.html