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#1 |
Registered User
Join Date: Jul 2002
Location: California central coast
Posts: 126
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White deposits in exhaust ports
Hi folks.
I just removed the exhaust manifold on my 250 inline 6, and the inside of all the exhaust ports and the exhaust manifold are coated with white powdery residue. It's rather thick -- about 1/16 inch (not just a light coating), and it comes right off in chunks when "persuaded" with a finger. I've seen manifolds full of black powdery gunk, from running too rich, but not t his white stuff. Is this perhaps burned soot? The truck had been running rich (probably for quite a while) when I got it; the idiot previous owner had disconnected the metering rod (and done lots of other really stupid things). So its history does resemble what I described above. Any ideas what this might be? Am I talking out of my posterior? The intake ports are yellow on the inside. Not nearly as thick as the exhaust deposits. Is this just 30 years of gasoline? TIA |
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#2 |
Senior Member
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
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im pretty sure white is from a lean conditon
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Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member. |
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#3 |
Registered User
Join Date: Dec 2001
Location: Spring Creek, nevada. U.S.A.
Posts: 456
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i'm not forsure, might be wrong but i think white is too lean.
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69 chevy short wide box project 70 GMC jimmy project |
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#4 |
Jostrans68
Join Date: Mar 2001
Location: Bloomington indiana
Posts: 1,182
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My .02 in most cases it is the remains of the additives in todays gas. I have seen them almost pure white to a light pink.
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![]() former 67-72 now with a 96 silverado |
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#5 |
Recovering Truck Driver
Join Date: Mar 2002
Location: Orleans, NE USA
Posts: 1,883
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if I remember right, white is lean, and it will also be built up heavy on your exhaust valves, pouring transmission fluid slowly in your carb at high idle will actually break up the white carbon and get rid of it for ya.
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67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska |
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#6 |
Account Suspended
Join Date: May 2000
Location: IL
Posts: 0
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white is always found on exhaust valves and sometiems in ports, its burnt additives of some kind or form, whtehr it be already in the fuel or added into the tank, its ok and wont hurt anything
good luck |
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