A little smoke

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Jun 2, 2009 | 01:39 PM

cbass139

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From: Chicago

A little smoke

Took the truck ('58 F100) for a trip around the block to check the brakes, which on another note need to be bleed, and when I poped the hood I noticed a very small amount of light smoke coming out of the oil fill cap. What is the cause of something like this? I drove it some 250 miles last week and didnt notice anything like this before.

Jun 2, 2009 | 01:50 PM

gearhead1952

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From: Arvada, CO

Nothing to worry about. That's the stuff pollution controls were invented to remove later in the 60s. PCV or positive crankcase ventilation captured that vapor and fed it back into the carb for burning. PCV came out late 60s and your truck lets that vapor out into the air.

Jun 2, 2009 | 01:52 PM

bobbytnm

Roast em' if you got 'em

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From: Rio Rancho, NM

I take it the old engine has quite a few miles on it? Its no big thing really, just a sign of wear and tear on the engine. What you are seeing is typically referred to as blow-by. The crankcase in every engine develops pressure and fumes while the engine is running, on new engines the Positive Crankcase Ventiliation system (PCV) handles most of it by routing the fumes, etc back into the intake. Older engines just have a vent tube or Road Tube on the crankcase along with a vented oil fill cap. The Road Tube typically runs down the side of the crankcase and the air flowing across it while driving will help to evacuate the fumes frorm the crankcase.

After you shut the engine off whatever fumes are left in the crankcase will find their way out....no biggie...well, unless the engine is using a considerable amount of oil....LOL

enjoy the ride
Bobby

Jun 2, 2009 | 01:53 PM

cbass139

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From: Chicago

Thanks for the quick reply, I was starting to cr*& my pants. I could already hear my lovely wife telling me how she thought this was a bad idea. I am sure that line is still coming but atleast I have bought a little more time.

Jun 2, 2009 | 01:57 PM

bobbytnm

Roast em' if you got 'em

Joined: Mar 2005

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From: Rio Rancho, NM

LOL....

See now, you can tell the little woman that everything is normal and its operating just like the factory designed it to. All you have to do now is convince her that its part of the quaint charm of owning and old truck.....

Bobby

Jun 2, 2009 | 04:08 PM

edzakory

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Joined: Oct 2008

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From: Prescott, AZ

I love the smell of blow-by in the morning.

However, if too much blow-by, it's a sign of excessive clearances, e.g., rings. Do a compression check on the engine and compare it to specs. Squirt oil into the cylinders and see if the compression improves. If out of variance, it may be time for an engine rebuild.

Jun 2, 2009 | 05:03 PM

Brian_B

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What they said.

My 56 Y-block does the same thing. I need to check the filter in the road draft tube. I keep forgetting. And no...mine leaks a little oil, but does not appear to burn much. I guess that is not too bad for a 53 year old engine.