Oil consumption through fuel pump??
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Oil consumption through fuel pump??
I have read somewhere that an oil consumption problem was fixed by replacing the fuel pump. I immediately dismissed it since I would think that if there is a problem with the fuel pump diaphram to allow oil in, then the pump would not be able to pump.
The only reason I even ask is that I've gone through just about everything on my motor and decied to just throw this out there.
Just for grins, I put in some oil dye in my crankcase and then put a black light over the carb to see if it would "glow". Sure enough, it glowed like mad, way more than I thought it should have. Then I put the black light over the opened gas tank and it glowed as well. I'm now guessing that they put some type of fluoresant dye in the gas making my little test invalid.
The only reason I even ask is that I've gone through just about everything on my motor and decied to just throw this out there.
Just for grins, I put in some oil dye in my crankcase and then put a black light over the carb to see if it would "glow". Sure enough, it glowed like mad, way more than I thought it should have. Then I put the black light over the opened gas tank and it glowed as well. I'm now guessing that they put some type of fluoresant dye in the gas making my little test invalid.
Burning Brakes
Joined: Dec 2000
Posts: 1,183
Likes: 2
From: Des Moines Iowa
Re: Oil consumption through fuel pump?? (Chris A)
Bad fuel pump can do any of the following bad things:
Cause poor engine performance, won't run or won't run at higher rpms
Leak engine oil from block onto engine surface and the ground, would cause a loss of engine oil.
Leak fuel into engine crankcase, diluting the motor oil, causing increased engine wear, and possible increased oil consumption, due to combination of thinner oil and too much of this oil/gas diluted mixture in your engine crankcase, which will cause excessive oil consumption as well.
Cause poor engine performance, won't run or won't run at higher rpms
Leak engine oil from block onto engine surface and the ground, would cause a loss of engine oil.
Leak fuel into engine crankcase, diluting the motor oil, causing increased engine wear, and possible increased oil consumption, due to combination of thinner oil and too much of this oil/gas diluted mixture in your engine crankcase, which will cause excessive oil consumption as well.
Safety Car
Joined: Aug 2001
Posts: 3,685
Likes: 202
From: Waterford Mi
Re: Oil consumption through fuel pump?? (john's '81 mouse)
I other thing is a bad diaphram which allows gas to squirt all over the engine compartmanet. To do what you are suggesting it would have to suck oil in and pump it up to the carb.
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: Oil consumption through fuel pump?? (Chris A)
Chris,
I wouldn't have expected oil to get back to the tank, but if you have a ruptured diaphragm I guess that would be possible through the return line. My oil consumption via the fuel pump is also quite high, but do to leaking through the tiny vent holes on the fuel pump neck. This is a brand new heavy duty Edelbrock pump. Whenever I hit high rpm's, it spews oil out in a major way, spraying onto the hot headers, making both quite a stink and a smoke screen!
Chuck
I wouldn't have expected oil to get back to the tank, but if you have a ruptured diaphragm I guess that would be possible through the return line. My oil consumption via the fuel pump is also quite high, but do to leaking through the tiny vent holes on the fuel pump neck. This is a brand new heavy duty Edelbrock pump. Whenever I hit high rpm's, it spews oil out in a major way, spraying onto the hot headers, making both quite a stink and a smoke screen!
Chuck
Racer
Joined: Apr 2002
Posts: 324
Likes: 0
From: port jefferson station ny
Re: Oil consumption through fuel pump?? (Chris A)
you have a weep hole at the top of the fuel pump housing that allows atmospheric pressure in and out so that the diaphram is able to pump. if you rupture the seal between the fuel pump arm and the "chamber where the top of the diaphram is (not gasoline), the arm of the fuel pump will allow oil that is thrown off of the camshaft fuel pump essentric to run into this chamber and be pumped out of the weep hole and outside the engine. it's not under pressure only drip oil inside the engine. wcj
Thread Starter
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Re: Oil consumption through fuel pump?? (wcj)
I'm not talking about an external leak, but oil actually being pumped in with the gas to the carb.
Chuck, I believe that there is some type of dye in the gas from the pump as everywhere that there is gas, it "glows" like the oil dye. I don't have a return line, so it's not possible that I'm leaking oil back there.
I read about a fuel pump causing and oil consumption in this thread: http://forums.corvetteforum.com/zero...454021#4454021
Chuck, I believe that there is some type of dye in the gas from the pump as everywhere that there is gas, it "glows" like the oil dye. I don't have a return line, so it's not possible that I'm leaking oil back there.
I read about a fuel pump causing and oil consumption in this thread: http://forums.corvetteforum.com/zero...454021#4454021
