Oil Catch can emptied on a THP 155, after 1396 miles

[FLP]

Is there a "How to catch can"-thread on here somewhere? I'll need to install one next year when my warranty runs out, and I'd like to inform myself in time But I can't seem to find a specific thread..

[cal23]

Great video.....looks a much better crema than my gaggia makes.

[dan265]

Guys..i studied a lot this problem..and the back hole its more important than front PVC

[lfcrule1972]

Back hole more important than the front hole??? Emmmmm I'm sure I've heard this before somewhere

[cyclone]

Back hole more important than the front hole??? Emmmmm I'm sure I've heard this before somewhere

Whaaay!

[Chris_Blue]

Anyone got a photo of the rear PCV outlets (Where to connect to)
One is on the back of rocker cover left hand side from what I recall

Think the pipe dives down somewhere- but where too?

[Jamie@SPTuning]

[cyclone]

That is the bottom of the intake manifold on your passenger side.

[Chris_Blue]

Which direction is the flow? Could I get away with leaving the bottom connected, and connecting the can at the top end?

[cyclone]

Flows from valve cover to intake manifold. Yes, just be aware that everything will be under boost pressure up to the valve in the valve cover. So make sure all the connections are tight, do not want a boost leak.

[Chris_Blue]

Thanks Cycles. Will be getting a catch can without sight tube for this pipe.

[Chris_Blue]

Emptied the catch can for a third time. 1500 miles further on from when i last emptied it, (Now at 17500 miles) and surprisingly theres nothing in it. Not a drop.
The drain cock was closed, and theres no oily mess below the OCC, so wonder why its empty? No oily mess on any other connection either.

Positioning of the rear, new, catch can is going to be a pain. LHS of engine as you look at it.
Only place can be put, if the air filter box isnt removed, is where Ive my air horns installed near the water bottle neck. Goodbye air horns then. (For now)

Even then, where the rear PCV exits the top of the engine at the rocker cover, will have to have a big U shape tube to get to where the can is
And the exisiting pipe will have to have some sort of connection to extend to the catch can position. Have sourced some steel wire reinforced pipe...hope it flex's
All these additions when the pipe is under negative vacuum pressure!

Will be fun

[Jamie@SPTuning]

Emptied ours tonight as well, just got 3-4 drops of very clean engine oil from the rear can, no signs of any moisture. And absolutely nothing from the front can.

[Chris_Blue]

Any ideas why? Maybe warmer months alter the misting position

[Czar]

Any ideas why? Maybe warmer months alter the misting position

This is often asked, I've answered it many times, and not just on this forum, let's see if we can answer it again.

Why do we capture more oil particles from the rear PCV line than from the right hand side (front) PCV line, simple answer, the rear PCV is open the majority of the time during any journey, the rear PCV is linked through a pressure differential sprung diaphragm, which is located in the camshaft cover, which is directional controlled by vacuum.

The majority of driving conditions are generally off boost situations, during off boost throttle positions, you will find that the engine cylinder vacuum draw, is greater than the vacuum draw from the off boost vacuum generated by the turbo, this pressure differential in favour of the engine cylinder vacuum retains the rear PCV in it's open position, it is only when the vacuum generated by the turbo coming onto boost situations, that the vacuum pressure differential changes in favour of the right hand side (front) PCV, this pressure differential closes the sprung diaphragm, closing the path way to the rear PCV and in turn opens the right hand side (front) PCV line, once off boost, the vacuum pressure differential will reverse, closing the right hand side (front) PCV and reopen the rear PCV.

Why do we capture water and sometimes not ?

Quite simply this is all down to thermal exchange (sweating) you have an Aluminium can, Aluminium is very good at dissipating heat, that said, when you put hot gaseous vapour through the can during the summer months, where we have reasonably high constant ambient temperatures, the thermal exchange (sweating) is reduced, as the temperature delta is minimised.

When we put the same hot gaseous vapour through the same can during the cooler months, the temperature delta between the hot gaseous vapour the much cooler ambient temperatures and the Aluminium cans rather good heat dissipation properties, increases the formation of water molecules inside the can, furthermore, during the colder months, it takes longer for the engine to reach it's working temperature, this also adds to the issue of water molecules captured in the Aluminium can.

As the ambient temperature drops, the temperature delta between the working temperature of the engine and the ambient temperature, increases, this temperature delta, increases the water molecules which form during the cooling of the engine, these water molecules which have collected in the engine during the cooling process, will dissipate with the heat generated by the engine.

Only once the engine is at full working temperature, and the colder the ambient temperature, the longer the engine needs to maintain a full working temperature, in order for the heat to dissipate the water molecules, if the engine does short journeys, where full working temperatures are not achieved or prolonged, the more water molecules will be captured in the Aluminium catch can, and subsequently the temperature delta of the Aluminium can, will create it's own water molecules, more in winter, less in summer.