Posted By: 1970RT
Smoke coming out of valve cover breather - 09/28/11 08:23 PM
Can someone tell me what would cause a lot of smoke to be coming out of the valve cover oil breather cap on my 440? My car had been sitting for a couple of months without being run and during this time I took the intake and valve covers off to clean and paint them. After reinstalling the parts, when I started it it now has blue smoke puffing out of the breather cap through the hose and into the air cleaner. It seems to run O.K. but the smoke is really noticeable and doesn't seem to be diminishing. Would this be due to a stuck valve or is it likely something else is causing it?
Posted By: bigsbigelow
Re: Smoke coming out of valve cover breather - 09/28/11 08:30 PM
I would have to wager that the smoke is condensation boiling out of the oil. Have you changed the oil? If not, you should.
A lot of water can collect in the crank case when the engine sits dormant for a long period of time. Do you use a PCV valve?
Posted By: RapidRobert
Re: Smoke coming out of valve cover breather - 09/28/11 08:39 PM
valley pan not sealing and drawing oil into the head intake port(s). I'd pull it & clean the head/intake port faces & I'd probably go ahead & get a new valley pan & if you used a new one when you painted everything I'd possibly reuse it & carefully clean the port opening area(s) on that one & my preference is to coat each of the 8 port openings in the pan on both sides with a LIGHT/EVEN coat of Permatex #1 in the toothpaste like tube (thick/viscous/seals well) with an iron intake and Permatex #2 if an aluminum intake
Posted By: WheelsUp73
Re: Smoke coming out of valve cover breather - 09/28/11 09:24 PM
What you describe is called blow by. Blow by is caused by Bad PCV system or piston rings and or piston ring lands being broken.I would first check the Pcv system for vacuum ,if that is ok then I would dump some cleaner down the carb when hot, let it sit for 1 hour then go drive the piss out of it.
http://youtu.be/t0OVIsU01mg
Posted By: dogdays
Re: Smoke coming out of valve cover breather - 09/29/11 02:08 AM
Blowby comes out the breather, especially if the PCV valve is stuck. Dip it in carb cleaner.
It can be caused by broken or bad rings, but can also be cased by stuck rings. I once got a great deal on a Toyota pickup that burned oil badly, took it apart and found the rings were glued into the pistons by gunk that had built up in the engine. A new ring set and engine gasket set and I was golden. I'd suggest what was said earlier, carb cleaner in the spark plug holes for a while, then drive it hard for a half hour or so. Hope this helps.
R.