Hi, I have an old Takeuchi excavator tb035 with a Yanmar 3tn84tl 3 cylinder engine. The breather hose that relieves the overpressure in the cylinder head now directly vents in the air. This comes unfortunately with lots of smoke and smell... The cylinders probably leak somewhat. Is it a good idea to connect that breather hose directly to the air intake (after air filter) so it is burnt, resulting in better (or less bad) emissions? (As is done in more modern engines) Or will this mess up the air supply or...? The machines is not used alot, so not worth redoing the entire engine for the couple of hours that I need it. Thanks for any advice in advance!
It will work for awhile but your muffler is also probably getting wet stacked already. Add all the crankcase vapors and you are living on borrowed time.
If too much oil goes through the intake side, you may end up with sticky valves or at the worst, engine runaway
There are Positive Crankcase Ventilation systems on most engines these days, on Gas engines in cars they tended to load the intake with gunk and oily residue that does NOT burn except in high compression engines as diesel, the latter have been adopted to this but it is not without drawbacks as a runaway situation where as the engines age and deliver far more consumable to the intake the fuel system can drop back SOME, when at its least and should you pop a piston forcing massive amounts of oily vapor into the intake off it will go to self determined destruction.
You could do it, but , BUT you have to place a slobber can in between. It's basically a condenser, let's the oil drip back to crankcase and the vapors get consumed.
I've had a couple of customers do it. I also had one plumb the hose into the outlet side of the muffler where the rain drain hole is. It just moves the mess from the under the engine to all over the outside of the machine.