oil catch can from valve cover hole (between plugs #3 and 4)

frontrow · Post by **frontrow** » 14 Jan 2016, 05:11

Hi folks
I wonder has anyone fitted an oil catch can to their 5 cylinder petrol engines with an input (to the catch can) pipe from that strangely 'open' hole in the head located on top of the valve cover between spark plugs 3 and 4? I've tried to search well beyond Matt's site for wisdom on whether or not this would work. There's no shortage of surprise from other Volvo owners that there would even be an apparently open hole located here. There are some references to the non-turbo version of these motors having some sort of anti-pollution plumbing (EGR?) piped into this hole (there are two threaded holes beside the 'open' hole to allow for a metal pipe with o-ring to be held in place). I just figured if my turbo motor (possibly with a head fitted from a non turbo engine at some stage?) could be fitted with a section of that EGR (if that's what it's even called) pipe, then i could easily hook up a catch can to that...... maybe....?
Hopefully someone can work out what I'm getting at here.
thanks guys

Post by **tryingbe** » 14 Jan 2016, 05:22

I mounted a oil catch can on the transmission and routed it between the oil trap box and the intake hose. It catches more water then oil.

frontrow · Post by **frontrow** » 14 Jan 2016, 05:28

Is that to say you spliced a T piece into the thick rubber hose from the valve cover that goes down between the manifold / injectors and into the plastic trap? Is water supposed to be anywhere near there? I've more or less made up my mind to give this idea a go so might take some pics to post too. cheers

Post by **rspi** » 14 Jan 2016, 06:18

frontrow wrote:Hi folks
I wonder has anyone fitted an oil catch can to their 5 cylinder petrol engines with an input (to the catch can) pipe from that strangely 'open' hole in the head located on top of the valve cover between spark plugs 3 and 4? I've tried to search well beyond Matt's site for wisdom on whether or not this would work. There's no shortage of surprise from other Volvo owners that there would even be an apparently open hole located here.

I'm pretty sure that hole is blocked in the head and is not venting anything. If you think it is just put a rubber plug on it.

Post by **tryingbe** » 14 Jan 2016, 06:23

frontrow wrote:Is that to say you spliced a T piece into the thick rubber hose from the valve cover that goes down between the manifold / injectors and into the plastic trap?

No, there is no T in my system. In stock form, there is a hose/tube goes from the vent box to the intake hose. I took that hose out, replace it with two flexible 5/8 oil resistance hose (not heater core hose) and route the hose to a catch can I mounted near the transmission, then route it to the intake.

frontrow wrote:Is water supposed to be anywhere near there?

By product of internal combustion is water vapor and carbon dioxide. Since the combustion gas escape to the crank case, and you're catching that crank case fume, when that fume condense, you will have water.

frontrow · Post by **frontrow** » 14 Jan 2016, 12:49

OK I see what you mean. Indeed I think that's likely the midst common way of plumbing a catch can in on these engines.

Yeah lots of folks who've found themselves one way or another with an engine where this hole is open and no fitting bolted up to it, seen to have just plugged it... Just seemed to me like such a logical place to plumb a catch can into.... Provided you can find at least s piece of the original Volvo piping with o ring to attach your venting hide to.

frontrow · Post by **frontrow** » 14 Jan 2016, 13:02

Apologies folks, hide =hose (slip of the thumb on the train)