Universal M25 diesel problems

[frogdoc58]

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

[Jon W]

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.

[Stu Jackson]

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

[frogdoc58]

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

[KWKloeber]

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

[frogdoc58]

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

[Ron Hill]

Ken : Have you looked at the belt alignment in your picture??   

A thought

[frogdoc58]

That's not my actual engine.  But I do see what you are seeing, the belt looks to be upside down.  Good eye.

[KWKloeber]

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.) 

[Ron Hill]

Paul : FYI, the cogs on the belt are for - Cooling.

A thought