Smoking when idle

[esfan]

Recently I found out my car is smoking sometimes at the idle, so I change my pcv valve but it is still smoking. I have a breather on the other outlet on the valve cover, is that the thing causing the smoke? PCV valve is attached to an oil catch can and there are small amount of oil dip in the can. Thanks!

Another thing I'm considering is if the oil smoke come out from the breather, does that mean I have a problem of oil burning? And will these smoke come across the firewall and do harm to the people inside the car?

[heydockyle]

I can't see the filter causing the smoke.

How many miles on car? Is it "burning" any oil. I know it is smoking, but when you check the oil is it usually low? If so, how low.

[occasional demons]

Another thing I'm considering is if the oil smoke come out from the breather, does that mean I have a problem of oil burning? And will these smoke come across the firewall and do harm to the people inside the car?

So where exactly is the smoke coming from? The engine bay, or from the tail pipe?

If smoke is coming from the breather/air makeup in the valve cover, then either The PVC system is not working, which is prolly not the case, since you just replaced the valve, or there is enough blow by in the rings to force the crankcase air out the breather.

I'm sure with enough exposure, any kind of smoke is bad for you.

[esfan]

The car is reaching 100k pretty soon. It's not really burning oil, the losing of oil is about 1/2 qt every 3k to 5k miles (majorly due to oil pan gasket leaking). The oil i used is Pennz Platinum 10w-30, oil filter is K&N.

The majority of the smoke come from the engine bay, some times the oil even come out thru the breather. PCV is working for sure since the oil catch can catches oil thru the PCV valve. But I'm not sure about what the "enough blow by in the ring" is. Does that mean the piston bear is bad or what? Thanks for explaining!

I just took off the breather and restore the factory setting except the catch can and CAI, the smoke disappears but I'm not sure if it will come back again. But when the air condition is turn to external respiration, I can smell something like oil though. This happens before and after restoring to factory setting.

Now I just wonder if the exhaust manifold gasket is good or not, but I don't see any smoke come out after the breather gone. So that may not be the case. So the concern I have now is the oil smell come from the air condition external respiration. However, if the vehicle is in high speed, nothing smells wrong at all. This only happens when idling.

I just heard smoke of oil burning is some kinds of carcinogen, which is not good at all...

[occasional demons]

Blowby would mean the rings/cylinder are worn.

It may just be your valve cover is leaking oil onto the exhaust manifold. If the breather was getting oil into it, it could have been dripping on the exhaust also.

If the oil fill cap is removed with the engine running, and you put a piece of paper over it, there should be neutral pressure: Not pushing it off, but just a pulsing/vibrating. If it is getting pushed off, and there is a lot of smoke pouring out, then the rings may be worn.

The best thing would be to either park it somewhere that isn't windy, and let it idle with the hood up, and try to see exactly where the smoke is coming from. If it is rising from the exhaust manifold, then it is prolly the valve cover gasket leaking. An exhaust leak would/may make a tapping noise, and the smell wouldn't be the same as burning oil. If it did smell like that, you would see heavy smoke from the tail pipe.

[esfan]

Thanks very much for the tips. I test the way about the oil fill cap. Not pushing the paper away just some little push in frequency. But there's some blue smoke come out after the car running for a little while. But I found some oil flowing line on the exhaust manifold, that's maybe caused by oil come out from the breather and got burned by the high temp of the exhaust.

[occasional demons]

Not pushing the paper away just some little push in frequency. But there's some blue smoke come out after the car running for a little while.

Likely needs the valve guides, and seals replaced. The exhaust guides become worn, letting the valve move a lot more, flexing the sels, which by now, don't stretch well. This lets too much oil run down the stem into the exhaust port, creating the smoke in the exhaust.

My exhaust guides were replaced at 112,000. I did not have any smoke tho. But from the way things looked , it prolly would have started very soon.

Since you are almost due for a timing belt change, just pull the head, and have valve job/guide replacement done. Mine only required exhaust guides. If you are doing the labor yourself, the valve job will cost around $200 to $300, depending on your area. Or a remanufactured head my be the cheaper/better(?) option.

Edit: Or is the blue smoke comming out the filler cap? For the mileage, that would be almost normal. you will get smoke/vapors there anyways, especially after shutting the engine off. As long as that paper is not being blasted, your rings are fine. Maybe not "as new quality" but nothing to worry about.

[esfan]

Sorry about the confusion but the blue smoke is coming out from the oil filling cap. So in this case it's fine right? Thank you very much for all those useful tips!