zep Posted May 23, 2009 Share Posted May 23, 2009 I've been noticing that I get a hell of a lot of oil vapour coming out my catch can's breather. Like, on a cold day I can see it coming out of under the bonnet!! I don't know much about this, but could it be that the oil is too hot from being passed through the turbo? I am yet to add an oil cooler to my setup. The engine runs beautifully, otherwise. Cheers Quote Link to comment Share on other sites More sharing options...
bubblegoose Posted May 23, 2009 Share Posted May 23, 2009 my gti-r used to blow shit loads out made a right stink in the car, but ive never seen it coming out from the bonnet Quote Link to comment Share on other sites More sharing options...
zep Posted May 23, 2009 Author Share Posted May 23, 2009 It's like a steamy vapour that I can see coming out the gaps between the bonnet and guards and out the grille! Quote Link to comment Share on other sites More sharing options...
peteretep Posted May 23, 2009 Share Posted May 23, 2009 not water from bhg gotten into oil? Quote Link to comment Share on other sites More sharing options...
Spencer Posted May 23, 2009 Share Posted May 23, 2009 yea with the oil cap off do you have shit loads of blow by? Quote Link to comment Share on other sites More sharing options...
zep Posted May 23, 2009 Author Share Posted May 23, 2009 Not sure, I'll have to take a check. What exactly should I be looking for? Quote Link to comment Share on other sites More sharing options...
Spencer Posted May 23, 2009 Share Posted May 23, 2009 a big beeze coming out of the oil cap hole, not a good thing on a new engine dude lets hope not Quote Link to comment Share on other sites More sharing options...
84_S12 Posted May 23, 2009 Share Posted May 23, 2009 Check whether your PCV valve is operating correctly. They are pretty cheap to replace so I'd just do it anyway. Also, is the breather on the catchcan actually breathing or is it partially obstructed by oil allowing a buildup of pressure? Quote Link to comment Share on other sites More sharing options...
bubblegoose Posted May 23, 2009 Share Posted May 23, 2009 still do it when the engine is fully warmed up? condensation boiling off maybe? i know some (refuse to slate awesome bike manufacturer) bikes (repeated experience at work) used to suffer with condensation in the engine quite alot leading to false head gasket alarms/wanting full refund on new bike obviously they had no open breathers to blow steams i should shut up now as i clearly dont know what im talking about Quote Link to comment Share on other sites More sharing options...
zep Posted May 23, 2009 Author Share Posted May 23, 2009 still do it when the engine is fully warmed up? condensation boiling off maybe? i know some (refuse to slate awesome bike manufacturer) bikes (repeated experience at work) used to suffer with condensation in the engine quite alot leading to false head gasket alarms/wanting full refund on new bikeobviously they had no open breathers to blow steams i should shut up now as i clearly dont know what im talking about Hrm, I was noticing it tis morning (cold morning) about 3 mins after I turns on the car, so defintely not warmed up. But I don't remember noticing it as bad once I had been driving for a bit... although I never had to stop after I saw it. Will have to check that out. Quote Link to comment Share on other sites More sharing options...
shizzl Posted May 23, 2009 Share Posted May 23, 2009 what colour is the oil on the dipstick and is there a creamy buildup under the oil cap?? creamy buildups are bad,never touch a chick with this.. Quote Link to comment Share on other sites More sharing options...
Truenotch Posted May 23, 2009 Share Posted May 23, 2009 Have you looked inside the can to see if it's holding any cream or water? Had this happen when running in an engine once and the vapour turned into a water/oil mix inside the small catch tank I had. Mine made visible vapour like you're describing but it also overheated = epic fuckout. Quote Link to comment Share on other sites More sharing options...
84_S12 Posted May 23, 2009 Share Posted May 23, 2009 Personally I would say it's normal for a catch can setup to breathe a mist of oil vapour and moisture, seeing as that is the point of crankcase ventilation? The vapour normally wouldn't be seen because in most unmodified engines it is being reintroduced to the intake manifold to be burned by the engine. I would be more concerned if your dipstick started blowing out of it's own accord. Quote Link to comment Share on other sites More sharing options...
zep Posted May 24, 2009 Author Share Posted May 24, 2009 Personally I would say it's normal for a catch can setup to breathe a mist of oil vapour and moisture, seeing as that is the point of crankcase ventilation? The vapour normally wouldn't be seen because in most unmodified engines it is being reintroduced to the intake manifold to be burned by the engine. I would be more concerned if your dipstick started blowing out of it's own accord. As far as I'm aware, the dipstick is staying firmly in place. But I'll check for creamy build ups, frothy water, water in the catch can, etc. Is it worth me trying to route the breather back into the intake? Quote Link to comment Share on other sites More sharing options...
CaMpylobacter Posted May 24, 2009 Share Posted May 24, 2009 it could work the pug stunk like fuck with catchcan and breathed quite heavily, for what i thought was aceptable. even popped dipstick out on trackdays when pushing VERY hard. didn't use any oil between changes though. If you don't use the car for many long runs, or leave it dormant for a while between times of use then you'll find water in the catch can, esp if it's an alloy blocked engine. I could leave my pug for a month then drive it to wellington only to find a 1 litre catch can about 1-% full of water. it didn't use a drop of water either. jsut condensation. Quote Link to comment Share on other sites More sharing options...
zep Posted May 24, 2009 Author Share Posted May 24, 2009 Hrm, that's pretty relieving to hear. I drive the gem about once a fortnight at the most so the water in the catch can could be happening. Still need to check all this stuff out. Hopefully will get some time soon, 'tis always dark when I'm home! Quote Link to comment Share on other sites More sharing options...
forced Posted May 25, 2009 Share Posted May 25, 2009 I've yet to see a catch can on a car with PCV system hooked up correctly. There's supposed to be a flow of air through the crankcase from the outside air to a vacuum source. Without that the oil gets contaminated with water, unburnt fuel and acids. Chances are it's wrong. As with all turbo motors , if you pull the plugs, put them in a row, check for oil on the threads.... that's the only clue you need to show it's got a broken piston. If the plugs are clean, you've got a good motor. Unless as above you've blown the headgasket, you'll know because you'll have needed to replace popped hoses, or radiator, or heater. Steve Quote Link to comment Share on other sites More sharing options...
Ke36 Posted May 25, 2009 Share Posted May 25, 2009 my car also breathes quite heavily aswell catch can (water bottle ) is slowly filling up but car is driven very infrequently and never uses water so like im not too worried i dont get any obvious vapour out under the bonnet tho have heard numerous stories of people hooking cans up and the cars smoking heavily tho and returning the setup to stock and the problem disappearing for what its worth, tis exhaust smoke tho as opposed to underbonnet Quote Link to comment Share on other sites More sharing options...
84_S12 Posted May 25, 2009 Share Posted May 25, 2009 I've yet to see a catch can on a car with PCV system hooked up correctly.There's supposed to be a flow of air through the crankcase from the outside air to a vacuum source. Without that the oil gets contaminated with water, unburnt fuel and acids. Steve Quoted for truth (+ post #666 ) The flow of air through the PCV is factored into the metered airflow in most fuel injection systems, much like plumbed-back blow-off valves and as such if you remove it a/f ratios get out of wack. Quote Link to comment Share on other sites More sharing options...
tortron Posted May 25, 2009 Share Posted May 25, 2009 interestingly the morrie just has a pipe which vents out next to the gearbox, never any vapour comming out of that Quote Link to comment Share on other sites More sharing options...
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