Hi All,
I have an '89 Catalina 34 with a Universal M 25 diesel. On the top of the engine next to the coolant tank is what appears to be a crankcase vent. Currently when the engine is running there is an oily vaper coming out of it. The vent has threads, maybe 1/2 inch JIC.
My questions are, is the discharge normal if so is there supposed to be a vent hose attached and if so where does it got to? Also, when I put my finger over it, pressure builds up.
Can anyone give me some advice.
Thanks, Paul
Most of us connect a hose and route it to discharge into the engine air filter. Depending the type of air filter some tie wrap the hose to the injector tubing, some drill a hole in the top of the air filter and attach a hose fitting to connect the hose, and some have routed the hose to an air/oil separator then to the air filter.
Paul, welcome. Here's what Jon was talking about:
Breather Hose 101 (w/ K&N Filter Pictures from Rick Allen)
http://c34.org/bbs/index.php/topic,8875.msg63915.html#msg63915
and Noah's: http://c34.org/bbs/index.php/topic,8858.msg64297.html#msg64297
Wow, that's a great solution. I will be getting right on it in a few days.
Thank you very much.
Stay safe and have a great sailing summer, well as best as you can right now.
Regards, Paul
Quote from: frogdoc58 on July 03, 2020, 06:47:35 PM
is the discharge normal if so is there supposed to be a vent hose attached and if so where does it got to? Also, when I put my finger over it, pressure builds up.
Paul
Look at pg 12 of your M25 parts manual that I know you have downloaded and keep handy. It shows the vent hose (which OEM just hangs into the bilge.)
There shouldn't he a huge amt of oil/gunk come out at any one time but over time it will and will stink up the bilge/boat. This has been covered many times on the forum if you do a search.
Yes the will be a slight pressure but if you have excessive pressure/oil/gunk you could have excessive ring blowby (check the engine compression.)
If you check the tech wiki site under >>engine<< there are a few suggestions how to route the crankcase vent to the air intake. Below is mine. Another way not discussed is to drill. tap, and use a hose barb on the intake manifold. The XPB has a knockout on the intake manifold to accept the crankcase vent hose.
-ken
Thank you all for your help. I made the modification. No more smoke and oil mist coming into the engine compartment.
I'm sure that I am getting excessive blow by, rings, but for now I will get through the season.
Cheers for now,
Paul
Ken : Have you looked at the belt alignment in your picture?? :shock:
A thought
That's not my actual engine. But I do see what you are seeing, the belt looks to be upside down. Good eye.
Ron: That's an OLD pic and I think there's a slight fisheye effect from the lens, but I will check it. THX!!
I plan some upgrading so it may be moot soon.
Paul: I find that my belt rides MUCH better when it's turned inside-out.***
Scroll down
VvVvVvVv
***(Actually it's a dayco "top cog," recommended for our small alternator pulley.)
Paul : FYI, the cogs on the belt are for - Cooling.
A thought