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Smoke out of the valve cover breather?

K85 Octane

K85 Octane

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Why? :( My PCV works and is clean, hooked up to the manifold and has plenty of vacuum. I just noticed today, while working on the timing, that when I blip or rev the engine, I get smoke coming from my breather. It is a little air filter.
 
skip the compression test and go right to a leakdown... check %'s and pull the oil fill and listen too..
 
it just started smoking? because ive heard of rings taking a couple thousand miles to fully seat.
 
ryoken said:
skip the compression test and go right to a leakdown... check %'s and pull the oil fill and listen too..
Click to expand...

Any links on how to perform? And what am I listening for?

This is only my second vehicle ever and first one I've messed with :doah:

wage92 said:
it just started smoking? because ive heard of rings taking a couple thousand miles to fully seat.
Click to expand...

I just noticed, which means nothing :( :doah:




going out to snap a picture of the spark plugs I recently pulled.
 
Leak down test you get a special kit and it will pressurize a cylinder and you can see if a certain cylinder is leaking or if multiple are. And if you take the pan off and there is blowby you will hear the air coming out the bottom of the engine. You can also see if valves are leaking etc. you can probably rent a kit
 
Wouldn't it be nice to know which plug went in which cylinder. Didn't think that far when I took them out. I don't remember whether I changed the plugs after the first time the engine was built or the second, so I have no idea how that oddball plug got in there :(






 
leakdown tool, like $75 to 100, and a compressor.....

pressurize each cylinder at TDC, compare percentages... different motors will vary depending on rings, tolerances, etc, but you want to see all within 5, 10% and in the 85 to 95% depending on how the mill was spec'd..

air noise coming out the tbi/carb is a bad intake, out the exhaust, exhaust... and crankcase/fill/pcv hole is rings/walls... which is what we're hoping is ok...
 
plugs wont mean anything... it's compression from the cylinders going into the crankcase past the rings..

we see this chit all the time on high hr boats... it's not gonna blow up tomorrow.. all motors have some blowby, but if the smoke is excessive, it's a sign of an issue..
 
thanks guys






...I hate this motor so much. It has cost me so much in building and rebuilding and it's still causing me problems. If there has ever been one thing about this truck that I would change, it is the motor. I can handle most of this truck, but the engine and setting it up has been a problem from the get go. :flipoff9:
 
Who assembled the engine? A machine shop or you?

What oil are you running?

When you built the engine was it a fresh bore with new pistons or just a freshen up?

Does it happen all the time or just when cold?

Sound like you may have a bad/weak sealing cylinder. But if it goes away when warm I would just ignore it and keep an eye on oil consumption
 
Yes , just drive it like was said, you might of just noticed it and was there before.

See if it gets worse at this point. Do the leak down test if you want to check anyways and if you find one cyl way off from the others you will know you have a problem.
 
Keep in mind he only has 2500 miles on it. Without the aid of some of that cylinder powder, the rings wont fully seat for atleast 5k miles. So it could also be normal leakage until the rings seat and it tightens up. But, all motors if equipped with the valve cover breather will push something out of them. Its the nature of the beast, they never will achieve 100% efficiency or 100% leak free short of something along the lines of Top Fuel or Blown classes where the smallest leak could create a huge financial meltdown. So, I wouldnt worry about it to much unless it starts becoming a smoke screen or oil droplets are spraying out of it.
 
454Sub said:
Keep in mind he only has 2500 miles on it. Without the aid of some of that cylinder powder, the rings wont fully seat for atleast 5k miles. So it could also be normal leakage until the rings seat and it tightens up. But, all motors if equipped with the valve cover breather will push something out of them. Its the nature of the beast, they never will achieve 100% efficiency or 100% leak free short of something along the lines of Top Fuel or Blown classes where the smallest leak could create a huge financial meltdown. So, I wouldnt worry about it to much unless it starts becoming a smoke screen or oil droplets are spraying out of it.
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True. I've got a fresh motor in the street truck with no PCV and its got minor smoke out of the breather.
 
Your not doing the engine any good running it with no PCV valve..it will eventually sludge up the oil and allow condensation to build up under the intake and it might even encourage oil leakage at the seals and gaskets..
Also a pcv valve is a controlled vacuum leak,that affects air/fuel mixtures,and can lead to overly rich running conditions...they rob no power ,so there is little to be gained by not having one,and much to lose..

I never realized that till I saw some old small blocks (pre-62) that had a road draft tube instead of a pcv valve,and they had a small 1/16" or so hole made into the base of the 2GC rochester carbs to compensate for the lack of a positive crankcase ventilation valve..
 
Looking at the photo of the plugs, uhhh, one of them looks different than the others.

Probably not causing your problem, but I'd make sure that you have the correct plugs in there!

Other than that... one of them looks slightly oily, but with low ish miles on a rebuild that might be OK. A functioning PCV system works wonders. Heck on some of the high HP VW engines, there's a vacuum pump on the case!

Clay
 
eh, marine motors rarely run pcv systems... a few of the more modern packages have em, but 95% of boat motors don't run em with no ill-effect.....
 
ryoken said:
eh, marine motors rarely run pcv systems... a few of the more modern packages have em, but 95% of boat motors don't run em with no ill-effect.....
Click to expand...

That might be true on a boat that gets driven a good amount every time its fired up,and at higher rpms ,that will get the engine up to temprature quickly and the oil heated up enough to boil out any condensation--boats probably get more frequent oil changes and better overall care taken to their engines than most vehicles too..the ocean is not a good place to break down,you cant walk home!..


In a car or truck,they suffer the most when they get used for short runs and dont fully warm up enough to get rid of the moisture in the crank case and oil ,and acids form and contaminate the oil...the pcv valve helps to prevent that,or should I say help eliminate the condensation , along with relieving the excess pressure in the crankcase from blow by...the advantages to having a properly working pcv system are many,and there is no real disadvantages to having one...
 
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