Exhaust Leak/Vaccum Leak/Gas Mileage
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Exhaust Leak/Vaccum Leak/Gas Mileage
Would having a minor exhaust leak leak cause a decrease in gas mileage? When I bought my truck the exhaust manifold gaskets to the heads were shot and it was leaking alot of air through there. I bought new gaskets and installed them but the drivers side still has a leak. Probably because it was ran so long like that before I got it and the manifolds were all pitted up. Now the noise caused by this is one thing, and doesnt really bother me a whole lot, but if this is decreasing my gas mileage then I would like to do something about it and fix it.
Next will having a vacuum leak cause a decrease in gas mileage? I'm pretty sure it does but just want to make sure. I think I might have a vacuum leak because when I am driving speed limit on the highway you can hear a little bit of a whine sound coming from the engine. when you let the gas off it doesnt do it, and when you give it gas it either doesnt do it or you cant hear it over the exhaust? But definatly a little something there when just cruising. Is this a vacuum leak?
Thanks for the help guys!
Next will having a vacuum leak cause a decrease in gas mileage? I'm pretty sure it does but just want to make sure. I think I might have a vacuum leak because when I am driving speed limit on the highway you can hear a little bit of a whine sound coming from the engine. when you let the gas off it doesnt do it, and when you give it gas it either doesnt do it or you cant hear it over the exhaust? But definatly a little something there when just cruising. Is this a vacuum leak?
Thanks for the help guys!
Moderator
Joined: Dec 2003
Posts: 97,703
Likes: 2,026
From: Saskatoon, Saskatchewan
A vacum leak will decrease fuel mileage.
Check it out in the Fuel Injection, Carburetion and Fuel System forum: https://www.ford-trucks.com/forums/forum72/
Check it out in the Fuel Injection, Carburetion and Fuel System forum: https://www.ford-trucks.com/forums/forum72/
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Lead Driver
Joined: Jan 2005
Posts: 5,800
Likes: 9
From: Rouleau, Saskatchewan
To check if it's a vacum leak just spray a little carb cleaner around the suspected area and if the engine revs higher you have a vacum leak.
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