Catch Cans?

Still a blossoming gearhead here, but knowing that catch cans were overwhelmingly recommended for the FSI and TSI engines, I'm wondering if they are a good idea for the turbo diesel as well.

So what about our common rail injection? Problems with blowby and valve deposits? Anyone anticipate a slew of catch cans being released for the TDI?

Any already available?

I'm sure diesels have a PCV system of some sort, since they're compression ignition and can run high boost, so they assuredly have some level of blowby, but to what degree, I'm not really sure. As I said in the other thread, I'll take a look at a local friends car and see if there are any viable options.

I've never heard of catch cans but if you Google it.

Home Made Oil Catch Can

Oil Catch Can/Overflow Tank

Oil Catch Can DIY

As Mike says engines have there own PCV systems so I wouldn't think that fitting your own additional system would be an advantage, not on a new engine anyway.

Keithuk said:

As Mike says engines have there own PCV systems so I wouldn't think that fitting your own additional system would be an advantage, not on a new engine anyway.

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I assume you're new to forced induction :iono:

While googling cans, you should have noticed that catch cans are a must for FI/DI cars, as the PCV systems primarily have emissions control in mind and not the life of the valves and engine.

I'm sure others can elaborate more accurately (as I'm no tech myself) but the catch cans collect a majority of the oil and water vapors present in the crankcase that would otherwise be rerouted through the engine.

saucer said:

I'm sure others can elaborate more accurately (as I'm no tech myself) but the catch cans collect a majority of the oil and water vapors present in the crankcase that would otherwise be rerouted through the engine.

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Yes I'm a motor vehicle technician at a college so I understand what they do and how the PCV system works but I don't know why anyone would want to add it to their system unless their engine needs a mechanical overhaul. If its that efficient then the manufacturers would fit them.

that's cool - if you're a vehicle tech, I'm not going to argue with you based on personal knowledge

but if you start to read up on the subject, you'll see that catch cans have been used for decades on the track, in supercharged rigs, turbocharge ricers - just about anything that isn't NA. From what I've gathered, manufacturers wouldn't dare leave the emptying of the cans up to a mass market of soccer moms and such, adding yet another form of maintenance that might destroy the engine on someone's car that's already too lazy to change the oil at recommended intervals.

I had a GTI before this, which was my first turbo, and probably read hundreds of threads (not only VW related) about catch cans and am now convinced they're a necessity for FI and need to be installed asap to prevent crippling carbon buildup.

I definitely don't feel don't pretend to be an expert but just a little info.

Old engines used to have crankcase breathers that exhausted to the air. I remember them on old tractors and antique cars. These were outlawed due to pollution and the PCV was created. PCV valves have to be changed infrequently because they get clogged with gunk. Some of that gunk maybe good for valve lubrication, some may be bad because of too much clogging the intake manifold.

I have driven a couple of diesels but never changed a pcv valve on any of them. My 2000 TDI used to clog the intake manifold due to excessive levels of EGR. This was fixed with VagCom decreasing the amount of EGR. (and several hours work taking the intake manifold off and cleaning it.)

I did have a catch can on my track 911. It was lot's of work keeping it drained out.