smoke is coming out of Oil Cap
08-11-2009, 04:30 PM
#11
5th Gear Member
Join Date: Apr 2007
Location: Texas Hill Country
Posts: 2,100
The smoke you see is probably oily crankcase vapor. All engines create some of this which is why we need an evac system such as the PCV. As engines get more worn out and rings get weak, this crankcase vapor increases from blowby which is combusting gas escaping from around the rings. When this happens, normal evac systems such as the PCV cannot keep up. That is one reason why racers use vacuum pumps or exhaust bung evac systems that can remove the gases more quickly because race motors will have more blowby than a janer motor. Unless you are running a race motor, if gas is escaping from around your PCV or pushing out the dip stick, you are generating more crankcase vapor than normal.
I do not want to alarm you, but here is the worst case scenario. If your rings are wearing out, then this situation will get worse over time. It may be 1000s of miles before the blowby gets bad enough to warrant a fix. You can try some oil additives to help with scored cylinder walls and worn rings, but the real fix is bore, hone, and new rings/pistons (i.e. a rebuild).
How many miles are on your current set of piston rings? Make sure your pcv is good. They are cheap to replace.
I do not want to alarm you, but here is the worst case scenario. If your rings are wearing out, then this situation will get worse over time. It may be 1000s of miles before the blowby gets bad enough to warrant a fix. You can try some oil additives to help with scored cylinder walls and worn rings, but the real fix is bore, hone, and new rings/pistons (i.e. a rebuild).
How many miles are on your current set of piston rings? Make sure your pcv is good. They are cheap to replace.
08-13-2009, 01:00 PM
#12
Thread Starter
Join Date: Jan 2009
Location: Poland
Posts: 48
urban_cowboy,
thanks for detailed explanation.
I don't know how many miles are on my current set of piston rings. My engine was actually taken out lately and it was taken apart, heads were rebuilt, new gaskets etc. I don't think my shop did something to piston rings.
I use zddp additive to my oil.
I will replace pcv valve just in case and see if it helps. Are there any more powerfull PCV valves that could help or in such case it won't work ?
thanks for detailed explanation.
I don't know how many miles are on my current set of piston rings. My engine was actually taken out lately and it was taken apart, heads were rebuilt, new gaskets etc. I don't think my shop did something to piston rings.
I use zddp additive to my oil.
I will replace pcv valve just in case and see if it helps. Are there any more powerfull PCV valves that could help or in such case it won't work ?
08-13-2009, 01:02 PM
#13
Thread Starter
Join Date: Jan 2009
Location: Poland
Posts: 48
urban_cowboy,
thanks for detailed explanation.
I don't know how many miles are on my current set of piston rings. My engine was actually taken out lately and it was taken apart, heads were rebuilt, new gaskets etc. I don't think my shop did something to piston rings.
I use zddp additive to my oil.
I will replace pcv valve just in case and see if it helps. Are there any more powerfull PCV valves that could help or in such case it won't work ?
thanks for detailed explanation.
I don't know how many miles are on my current set of piston rings. My engine was actually taken out lately and it was taken apart, heads were rebuilt, new gaskets etc. I don't think my shop did something to piston rings.
I use zddp additive to my oil.
I will replace pcv valve just in case and see if it helps. Are there any more powerfull PCV valves that could help or in such case it won't work ?
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