I have 95 Honda accord with 2.2L Vtec engine with 200k miles. When engine is running, lots of air comes out of the oil cap. I thought it needs oil change then changed oil, but it is still blowing air. The air is not blue and not white. It smells and looks like exhaust. And the car runs same as it was before. I told the problem to mechanic after changing oil. He said me it is not a problem. But I am worrying about it. Is it a problem? If yes what is the problem and How much does it need to fix?
Thanks

 

u sure its not your radiator fan that is blowing the air?

 

No, it is not. Air comes out of the the oil filling cap, when the engine runs.

 

try a different cap then

 

Cap works fine, I mean air comes when the cap is removed from the engine. it is like exhaust. I think It is not supposed to blow any air. It is strange, isnt it

 

Its normal for higher mileage engines , its called engine blow by. On compression stroke when the air fuel mixture is compressed/ignited some of the mixture gets past the piston rings and into the crankcase, and is then removed by the PCV system. The engine is 200k miles so just like your mechanic said, nothing to worry about.

 

Thank you for helping me 3zFree;
Do u think i need to fix it? Because in my previous oil change, there was no air comes out of there. Its new for me.

good night

 

Yup, its normal. If you remove your PCV from you valve cover; it'll do the same thing.

 

x2.

Completely normal, especially for a higher mileage engine to have some blowby/ positive crank case pressure.

Even on a fresh motor its present. Its normal.

 

agreed x3, normal.

 

Thanks for helping me guys
One more question:
How can i prevent that?

 

you cant prevent it , its normal. the only way is not to turn your engine on,

 

Blowby is impossible to stop even in a new engine, thats why they invented the PCV valve, to get rid of positive pressure since there is no way to prevent it completely.

If it was causing enough blowby through the piston rings to be an issue you would have already noticed peformance problems such as low power and/or rough running engine

 

it's possible you're PCV is clogged (or the PCV hose) causing excess build-up... you could replace the PCV if it makes you feel better.

i do agree that it's a normal condition of any typical automotive 4-stroke engine. i'm actually kind of suprised you don't get oil splatter with the fill cap off..! i've seen cars w/o a cap on idle and splash oil all over the engine bay.

 

Na, the SOHC engines don't sling much oil near the oil fill cap @ idle. There is a substantial baffle or sling plate near the oil fill cap. I always ran mine for a few minutes after an oil change without the fill cap on. Mind you I wouldn't want to rev it up and drive away though...lol

 

x2.....

when i service cars i sometimes forget to put the oil cao back before starting it to pump oil intot the oil filter and it makes that sound...even on newer cars...

 

Normal

 

Although you can never delete positive crankcase pressures, you can always minimize pressures. It's a mod not everyone will attempt to do, but is highly recommended. Drill your valve cover, weld -10AN fitting on it, attach -10AN hose to this end, trace this hose to the other end where it will go into your oil-catch can w/ a filter on top. ( 2 ) -10AN fittings are better than ( 1 ), research "oil catch-can" and you'de be surprized by the advantages all around.

 

define the bolded more specifically..cause ill do it..

beside i have a 1992 b18a1 and it has a breather box next to the oil filter..one hose returns to the block and the other to the intake...

would that be the same???

 

I agree with what this gentlemen proposes with some additional thoughts of my own. A healthy PCV system will impart a slight negative pressure to the crankcase when operating properly. This is to evacuate any contaminants (acids, etc) which boil off when the oil heats up.
As a PCV system becomes less effective (lack of service / attention) it (along with protracted oil change intervals) contributes to the formations of sludges (the black stuff that shows up in too many valve covers).
This contributes to increasing problems with flows and blockages (inoperative PCv systems, oil starvation and drain-back problems).

I would suggest two things:
The Maintaince approach:
Replace the PCV Valve and confirm that there is unrestricted flow thru that system.
The Chemical approach:
Next oil change, get yourself enough to do two changes.
Purchase either Rislone, Seafoam, or GM Top Cylinder cleaner (now mascarading as Fuel Injector cleaner).
Perform your oil change and add the product you selected to the oil.
Start the car and drive it locally for as long as you feel comfortable (several hours should be sufficient), avoiding heavy loads to the engine (no land speed record attempts, please)
Perform the second oil change with a new filter.
Don't be surprised at how black that recently changed oil comes out.

This may be enough to restore ventalation.

P

 

Hey P Adams, Please make it short, I don't feel like reading a book. Thanks.

 

Sorry, I forgot that there are people out there (who) get bad headaches when reading anything other than comic books.
Could I suggest Powerblock TV? that way you could avoid reading all together..... :-)

P

 

There is no book. The guy was nice enough to give you guys a step-by-step on how to help your motor out. Tell ya what I'll go draw some pictures and color them with crayon. Would that be better?

Good advice Adams. I'll keep it in mind when I have my motor back in. Thanks. (Gotta go before I write a book!)

 

Get your ignorant, rude and immature self off this site. Go watch some more Fast and Furious or something. This man is being nice and trying to help the guy out here by giving him some great tips. So GTFO if you can't handle reading some basic literature.

 

op....pull the pcv valve off the valve cover and shake it. if there a slight tap noise, your pcv valve is doing good. It wouldnt hurt to remove it and spray some throttle or carb cleaner in there to free up some gunk. Or better yet replace it, replacement at any automotive store should set you back 3-5 bucks. good luck