overflowing catchcan

Resto · Apr 25, 2014

Hi I recently installed my forefront catchcan, and last week went away on a camping trip with loaded vehicle and loaded off road camper for 200km to campsite.
Once ther i noticed oil residue all down the side of the Nav (03 d22 zd30), poped the bonnet to see the catchcan had overflowed and spewed oil everywhere.
I have a 30cm drainhose with tap that was full and so was the catchcan.
To me this seemed quite excessive, and once i checked the dipstick i had lost roughly 500ml of oil.
I topped up the oil, cleaned the mess and then rediverted the pcv hose back to standard setup for the trip home.
I do have 260,000km on the Nav.
It seems that the catchcan is working too well, there was not one speck of oil going back into the intake, and after four days of being disconnected from the engine, my drain tube on the bottom of the catch can is nearly full again!!!!( read catch can not connected to anything).

motojunkie86 · Apr 25, 2014

wow that's crazy.
excessive blow by caused by way too warn piston rings? or is your catch can mounted lower than the breather hole on the rocker cover? coz I could kinda understand it filling up quickly if the oil splashed against the breather hole and could easily just flow down the tube into a catch can if it were lower? maybe im wrong but I would bet excess crank case pressure.

Al · Apr 25, 2014

Resto said:
Hi I recently installed my forefront catchcan, and last week went away on a camping trip with loaded vehicle and loaded off road camper for 200km to campsite.
Once ther i noticed oil residue all down the side of the Nav (03 d22 zd30), poped the bonnet to see the catchcan had overflowed and spewed oil everywhere.
I have a 30cm drainhose with tap that was full and so was the catchcan.
To me this seemed quite excessive, and once i checked the dipstick i had lost roughly 500ml of oil.
I topped up the oil, cleaned the mess and then rediverted the pcv hose back to standard setup for the trip home.
I do have 260,000km on the Nav.
It seems that the catchcan is working too well, there was not one speck of oil going back into the intake, and after four days of being disconnected from the engine, my drain tube on the bottom of the catch can is nearly full again!!!!( read catch can not connected to anything).

Damn I know the zd30 do blow by a lot of oil but that does sound abnormally high. I never get that much in my catch can. (Provent 200). I'd investigate it further.

Old.Tony · Apr 25, 2014

Let's make sure of something first - I do apologise if you got it right, but there are dozens of us out here thinking how such an event could be possible and I do like to start with making sure the basics are done right. Solid foundations and all that.

The catch can should be directly connected to the hose that comes from the top of the camshaft cover (looks like it's just behind the oil filling cap). If that's right, let's move on.

There should only be TWO connections to the catch can. One is the hose in the previous paragraph, the other is the hose heading to the intake (or vented to atmo as some people do). There should NOT be any other connections. I've been thinking about the one-way valve fed back into the sump idea and the more I think about it, the more I think of the problems that could be caused if the one-way valve was in backwards, or stuck open etc.

The crankcase oil should NEVER be overfilled. Too much oil is not as bad as not having enough, but it will cause issues with the motor. Levels are good? Okay ...

If the setup is physically right, the oil is being blown out of the crankcase in a big way because there's too much pressure in there - and that can only really be caused by loose piston rings/damaged or worn bores. It's time to remove the glows and do a compression test, I think!

tweak'e · Apr 25, 2014

i would suspect the engine was overfilled with oil. they blow out heaps when overfilled.
make sure ute is level and engine is stone cold before checking the dipstick.

Resto · Apr 25, 2014

Hi the catchcan is mounted on the back of the fuel filter bracket (rear of lhs skirt)so is higher, yes the hose comes from the back of the rockercover (lhs) and is originally plumbed straight into the air intake just prior to the turbo. One in and one out. But there is aslo a drain tube on the bottom as i mentioned.
Yep being a fairly high km engine i suspect its rings...