Crank case breather smoke (1 Viewer)

Joined
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I was driving down the highway today and noticed smoke blowing back inside the cab. All guages were reading ok. Pulled over and opend the hood and saw smoke coming out of the crank case breather along with some oil. Turned the truck on and the breather looked like a mini choo choo train..puff puff puff. The oil levels are normal and does not look like their is coolant mixed in. Smoke was coming out of the dip stick tube as well.

Any ideas what could be causing this? I have a '75 with a 2F
 
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Sep 6, 2009
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You are getting a bunch of blow-by from your rings. How many miles on the engine? Is the exhaust clear of smoke?
The rings could be worn or cracked or stuck.
I would squirt a tablespoon of marvel mystery oil into each cylinder and let it set for 2 days. If the rings are stuck this might help.
 
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The exhaust is clear of smoke. Mileage on the engine is probably 180K....there is 80K on the odo. I just recently put a new head on in Oct 09. I am running a Weber carb. It has been running great and then all of sudden smoke city from the engine bay.
 

brooklyn

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May 11, 2007
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Check the hoses

If your crank case is not vented correctly this will occur; I agree check your hoses.
 
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I've never had a hose or filter on the breather and have had it that way for quite some time with no issue. What other hoses should I be looking/checking for? Do you think an exhaust valve could be stuck open?
 
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unoman, can you take a picture of your setup? i have a 75 2F as well and i have a hose from my pcv valve that runs to the exhaust manifold but my breather on my valve cover was just open when i purchased the truck. i was wondering if i needed to just buy a filter or run it somewhere- of course i also have a weber carb so if it plugs into the stock carb somewhere i may be out of luck-
 
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I can take a picture when I get back to the house tonight. I've seen many people run a small filter on the valve cover. Even if I had a fliter on, this still wouldn't help my situation except slow down the amount of smoke exiting.
 
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Jan 22, 2003
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Kansastitty
I can take a picture when I get back to the house tonight. I've seen many people run a small filter on the valve cover. Even if I had a fliter on, this still wouldn't help my situation except slow down the amount of smoke exiting.

Seems like something is excessivly pressurizing your crankcase. Do a compression test, you could have a hole in a piston.<<<<WAG;)
An exhaust valve stuck open would not pressurize the crankcase.
 
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I am going to do a compression test tonight. If an exhaust valve is stuck closed, wouldn't that force exhaust down past the rings and out the breather? I'm just trying to brainstorm this weird thing.
 
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Joined
Jan 22, 2003
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Kansastitty
Runs back to the aircleaner. You can put a little filter on that.
Sorry if I misunderstood your question.
 
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now if someone just knows the size of that tube coming out of the valve cover i can order a nice filter today at work :)
 
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my truck was doing that so I checked my compression. I had 2 dead cyl. On my f1.5 only 4 comp rings out of 12 were still in one peace! Sorry but I think you are done for.
 

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