[matto3008]

Just noticed this. It's been like this the whole time I've had the car so... what is this and should I put a hose clamp on and reconnect it?

[matto3008]

To elaborate, this is a Toyota carb. I just thought perhaps it had be disconnected intentionally for performance reasons and am wondering what it does, and if there would be any reason to connect it.

[matto3008]

Reconnected it with no noticeable difference. Would still like to know what it's for

[MrRocky]

Rocker cover beather ?

[fordem]

I think the rocker cover breather is the top hose, he might be asking about a smaller hose - the open end is alongside the fuel filter.

[MrRocky]

Mines plumbed in like this
Also a toyota carb

[fordem]

Not my car so I've really no stake in the discussion.

Look at the second picture follow the rocker cover breather hose, up and over to the hose clamp where it tees into the hose to the air filter - now - switch to the first picture - look immediately right & below the hose clamp, you'll see a smaller open hose end alongside the fuel filter - that is what I think he may be asking about - it might be from the PCV valve, but it looks a little too small (diameter) to me.

[matto3008]

MrRocky wrote:

Mines plumbed in like this
Also a toyota carb

Yeah I see yours is connected. It was blowing oil over the carb so I might leave it connected. Thanks

[matto3008]

So I've since heard that some people plumb this down to their chassis rails to prevent rust!? Anyone else heard of anyone doing this or do it themselves? Sounds pretty illegal. Just curious, not thinking of actually doing it

[Gwagensteve]

On passenger vehicles, yes, crankcase vapour is supposed to be returned to the intake to be burned, but if the engine has lots of blow-by, that can cause plug fouling/poor running/upset mixtures, so it's not out the question to dump it into the chassis. ON modern direct injection engines, the lack of fuel "washing" the manifold and cylinder head ports means crankcase vapour carbons up the intake, reducing flow. This is true for both petrol and diesel.

I plumbed the crankcase vent into the chassis of my Gwagen his many years ago as I'd fitted a catch can but found the vapours from the (vented) catch can were annoying in the cabin. It had a fair bit of blow by, not uncommon on OM617 diesels.

Illegal? yes, but there's normally bigger fish to fry like oversized tyres, tyre coverage or no mudflaps, so I wouldn't be too worried about it.

Biggest problem with a Sierra is there aren't any holes in the chassis around the engine bay to plumb a hose into - it's a closed box. Additionally, if there's enough oil vapour coming out of a G13 to usefully prevent corrosion, then engine needs to go in the bin.

[matto3008]

Gwagensteve wrote:

On passenger vehicles, yes, crankcase vapour is supposed to be returned to the intake to be burned, but if the engine has lots of blow-by, that can cause plug fouling/poor running/upset mixtures, so it's not out the question to dump it into the chassis. ON modern direct injection engines, the lack of fuel "washing" the manifold and cylinder head ports means crankcase vapour carbons up the intake, reducing flow. This is true for both petrol and diesel.

I plumbed the crankcase vent into the chassis of my Gwagen his many years ago as I'd fitted a catch can but found the vapours from the (vented) catch can were annoying in the cabin. It had a fair bit of blow by, not uncommon on OM617 diesels.

Illegal? yes, but there's normally bigger fish to fry like oversized tyres, tyre coverage or no mudflaps, so I wouldn't be too worried about it.

Biggest problem with a Sierra is there aren't any holes in the chassis around the engine bay to plumb a hose into - it's a closed box. Additionally, if there's enough oil vapour coming out of a G13 to usefully prevent corrosion, then engine needs to go in the bin.

Amazingly insightful post as always Steve. Cheers, you've answered all of my questions