Ventilation Hose (between throttle body and engine)

[BIGBOBO]

Yesterday my car stalled on the way home. After a lot of juddering and trying it started again and I was able to limp it home.

Upon inspection today it seems that the hose in the picture wasn't connected. I probably forgot to connect it earlier this week while fixing a vacuum leak.

Now, what does this hose do and could it have damaged anything? I did drive quite a while with it disconected, 50km or something.

[pantera2075]

It's a breather from the cam cover back into the induction. Your car will have been running really lean with it disconnected but I doubt it would have harmed anything.

[crazybrightman]

its the breather hose for the engine, it just burns off any vapour or blow by gases from inside the engine.without it connected the inlet manifold will have just been drawing in a small amount of unfiltered air. its unlikely to run very lean as the fueling is done on map, tps and rpm so a small leak should be fueled for by the map sensor. it basicaly has the effect of having the throttle slightly open all the time

[LimeyMk1]

BTW the PCV deposits the blow by to a point before the throttle plate so will not effect the map signal.

[BIGBOBO]

Would it explain the stalling and juddering?

[LimeyMk1]

I wouldn't have thought it would have caused the stalling and juddering but I'm not 100% on that.

Has returning it to the manifold cured the problem?

[jimi]

BTW the PCV deposits the blow by to a point before the throttle plate so will not effect the map signal.

Surely it's after the throttle butterfly since it goes to the intake plenum and is virtually the same point the map sensor reads from ? and it will affect the map sensor reading if it's allowing air to be drawn in.

[LimeyMk1]

BTW the PCV deposits the blow by to a point before the throttle plate so will not effect the map signal.

Surely it's after the throttle butterfly since it goes to the intake plenum and is virtually the same point the map sensor reads from ? and it will affect the map sensor reading if it's allowing air to be drawn in.

Nope, if you squirt carb cleaner/wd40 down the hole it comes out before the TB, there's some wierd internal channels in that manifold.

Made me scratch my head a bit when I saw it, but it kinda makes sense as you don't want any positive pressure from the blow-by messing up your MAP signal do you?

[jimi]

Didn't know that an interesting piece of info to store away

[SuperRedMR2]

I had something like this happen about 5 months ago. It just slowed right down, lots of spluttering and I limped home. Couldnt accelerate much whatsoever. We found that I had done an injector.

[tom_snelling]

Is it not worth fitting an oil catch tank here and bunging the intake side?

[Tiny]

on N/A cars its not quite as important but it does prevent detonation as oil particles in a combustion chamber can cause det and it will stop you getting hot greasy deposits in your intake manifold. Depends on your cars condition if your engine is really nice and tight then you shouldnt see hardly any oil at all being "blown through" if its not then maybe worth fitting a catch can HTH