Author Topic: whats missing and why is it smoking?  (Read 4028 times)

Offline txchainsawgogi

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whats missing and why is it smoking?
« on: July 31, 2010, 06:08:41 pm »


So, what did that tube and spot on the exhaust manifold go to? Why would that breather tube be smoking after only a few minute drive? I know I need fresh oil...buuuut...

Offline zieg85

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Re: whats missing and why is it smoking?
« Reply #1 on: July 31, 2010, 06:11:25 pm »
That tube normally goes to the stock air cleaner.  If it is smoking that usually is blow-by from worn rings.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline TexasRed

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Re: whats missing and why is it smoking?
« Reply #2 on: July 31, 2010, 06:19:55 pm »
That spot on the exhaust manifold is usually connected to a thin tube type thing and goes to the Thermostatic flapper in your stock air cleaner assembly. It opens when it's cold outside to give you a little warmer air intake before the engine warms up for better drive ability.

Offline txchainsawgogi

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Re: whats missing and why is it smoking?
« Reply #3 on: July 31, 2010, 06:45:15 pm »
That tube normally goes to the stock air cleaner.  If it is smoking that usually is blow-by from worn rings.

 How would I know for sure? No real way unless I open it up?
« Last Edit: July 31, 2010, 06:55:21 pm by Blazin »

Offline zieg85

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Re: whats missing and why is it smoking?
« Reply #4 on: July 31, 2010, 07:24:14 pm »
That tube normally goes to the stock air cleaner.  If it is smoking that usually is blow-by from worn rings.

 How would I know for sure? No real way unless I open it up?

That tube hooks to the crank case breather in a stock air cleaner.  Does your truck use oil?  If you have the stock air cleaner the smoke would be sucked into the carb.  A true compression test, wet versus dry will help determine the condition of the rings but I am sure a more experienced member will chime in.  I know enough to be dangerous and fix my own stuff with the help of the many experienced quality folks hanging out on this forum.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Josh454

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Re: whats missing and why is it smoking?
« Reply #5 on: July 31, 2010, 07:32:01 pm »
You can install a breather in the valve cover grommet.  It would have a filter on it so it's not just an open hole in your valve cover.  Like the other people that said, excessive smoke could indicate bad rings.  If you motor's original they have probably seen their better days.  You will get some blow by on almost any engine.

Offline eventhorizon66

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Re: whats missing and why is it smoking?
« Reply #6 on: July 31, 2010, 08:50:27 pm »
You can install a breather in the valve cover grommet.

^^ Do this.  You are giving dirt and water a direct path into your crankcase.
'85 C10 SWB 350 700R4 TKO600