What are all of the causes for smoke coming out of the oil fill cap. I drove my car for about 20 minutes today and took off the oil fill cap. There is yellow crap in there (water/oil), could this cause light smoke to come out of the fill cap (after the car is turned off) or is it a sign of worn rings, or some other problem?

 

If it's got yellowish colors because you have green coolant instead of red Dex-cool, then you may have a bad head gasket. If coolant's in the oil something's up. You know that.

I get very light smoke out of the breather( no pcv system), but if I take off the cover and look in even if I take out the tint that clean Mobil 1 gives, it still doesn't look yellowish.

 

I just changed my head gaskets and haven't drained the coolant yet so I know there is SOME coolant in the oil. I just haven't gotten the chance to change it yet. Just wondering if the smoke could be water vapor or bad rings. I also have no pcv system. Just a vent line.

 

For comparison my breather smokes about the equivalent of 1-1.5 cigarettes at idle. The smoke is mostly white with a hint of blue. Is there a sweet burning smell or any kind of odd smell?

 

hmm, never smelled it. I'd say mine smokes about = to yours. Is it just the vent or is it actually smoke from burning oil?

 

That's oil vapor that goes into the intake and turns back to liquid oil when enough builds up in the intake. If you ditch the pcv that oil vapor goes into the air instead of being recycled into the intake.

Unless the oil gets watery again after you change this oil or if you have a really sweet smell, I'd say it's about normal.

 

I have ditched the pcv. I run a vent tube similar to your breather but instead it's a line that goes from the pass. valve cover down underneath the car. How much would water in the oil hurt the car anyhow?

 

Damage from water is caused from loss of oil film at higher rpms. you'll spin a rod bearing if you have a ton of water.

If it's a continuing issue the source must be fixed. After a heads and cam deal money's probably tight. If you can spare the $50 for a filter/oil swap it's worth it. If you find water after the change you've got some more work to do.

 

yeah, I've got 10 gallons of oil at the house so I just got to get a $5 filter Thing that sucks is I had changed the oil about 500 miles before all of this crap. After the swap I had drained the oil and it didn't appear to have any water in it. So I just put it back in. Now I have had my car at a shop for 1 week for a battery problem. So they have started it several times without letting it get to operating temps. I have heard that this can cause the oil fill cap to have the yellow stuff due to the engine not getting hot enough to burn off the condensation. So that might be it. I'll drive it around a day or two more and see if it goes away.

 

if you know there is any amount of antifreeze in your oil change it before you spin a bearing. i ruined a healthy 350 because i was lazy. front of the intake leaked oil so i changed after work one night. drained the coolant, pulled the intake being careful not to spill any coolant that might have been in the intake yet. changed the gasket and drove the car 3 miles home and it was knocking hard. drained the oil the next day and let it sit a while and sure enough just a little bit of antifreeze. i had done this a lot of time like this before with no problems and it only took one time to bite me in the ***. if i were you i would change your oil like right now and hope the damage isn't done. just trying to keep the worst from happening to you

 

A little smoke coming out oil fill is normal. Excessive amount is signs of blow from worn rings or scratches in cylinder walls. A small amount of the yellow/white stuff in the top of the filler cap is also normal is condensation mixing with the oil.

If you have water on the oil dip stick now that is a sign of water from coolant system leak, fix asap or you got your self and rebuild coming.

 

Oil change today

 

 

glad to hear that.

 

Everything's great. Just water in the oil from pulling heads, like I figured.

 

Coo foo!