Engine Breather Pipes/System?

[shimmy]

Can anybody explain to me about this system

1. what does it do?
2. how does it work
3. what would happen if it got blocked or leaked?

[AlexGTT]

Shim, engine breather system vents any pressure build up and excessive oil vapour from the engine crankcase. As the pistons move up and down and to a certain extent as crankshaft rotates, any piston blow by (there is some in every engine) starts to pressurise the crankcase. A breather system simply vents this pressure.

In earlier years, venting to atmosphere or a catch tank of some sort was all that's required. However, as emissions regs increased this led to slightly more complicated systems to "re-cylce" the pressure into the induction system.

If it blocks there can be excessive pressure build up leading to oil leaks. A leaking system will simply be messy but may also lead to rough running if it's linked to the induction manifold.

Hope that helps.

[The Gorilla]

Hi,

Shimmy- there was a thread when
''CantFindOne'' fitted an Oil Catch Tank
which was on the same theme.

As AlexGTT has already posted, its
about Emissions etc

I beleive a Catch Tank is a ''Fail'' in
some European Countries under things
like TUV or CTt.

Regards,

The Gorilla.

[shimmy]

cheers guys, but what could happen if the system is blocked or leaks?

im particularly thinking about overheating again

[shane@mbtech]

Originally Posted by shimmy

cheers guys, but what could happen if the system is blocked or leaks?

im particularly thinking about overheating again

It would promote premature engine wear if they were severely blocked, but to get to that stage IMO you would note engine oil leaks first.

PM me everything you have changed on your car.

[AlexGTT]

Shim, it won't lead to overheating. The excessive pressure build up starts to push pressure/oil past various oil seals in the engine. The main problem would be leaks pass main crankshaft seals, cam seals, etc. It may even blow a breather pipe off/dip stick out, that sort of thing. Also engine pumping would increase leading to small power loss.

The end result would lead to engine wear/damage as Shane said but you'd have to have absolutely no mechanical sympathy if you let it get that bad. Even you'd notice.