how much fuel in oil can an engine stand.

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9,448
Location
USA
My personal opion is that this engine is going to have sever bore polishing isues and high bearing wear if 10% fuel readings have been on going! Is this an old air cooled engine?? Is this a piston aircraft engine with mixture controls??
 
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6,614
Location
southeast US
Drop, Are you doing anything about it? I seem to have a similar problem with my subaru (4% fuel). Run couple of injector cleaners (redline and techron), cleaned PCV and will retest soon. Not sure what else to do. Thanks
 

drop

Thread starter
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14
Location
Mexico
I´m taking this to Daimler Chrysler, it´s under warranty yet. You should check injector leaking, I´m not sure an injector cleaner can fix it, probably could make it worst, no idea. You must find the reason fuel gets inti oil.
 
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6,614
Location
southeast US
Hi Drop, What was the outcome of the visit? When I brought my car to the dealership for a recent recall, I asked a service person to look into it. Even though I produced a copy of oil analysis and complained about poor milage (currently 14-15 MPG in mostly city driving and 10% towing), the dealership did not want to do anything about it. My car still has powertrain warranty. I will retest soon.
 
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9,448
Location
USA
I would also try another dealership. It is too easy to do a leak down test, pressure test,flow test, noid/gizmo test and then read codes and hook up to data stream. With that much fuel dilution the OBD II system should be going nuts! Between standard fuel system tests and useing the gameboy they should be able to solve this quick and easy! You need to contact the DC Customer Service line. THen ask to speak to Area Service Manager. If this does not work threaten to sue and start third party arbitration!!! 10% is insane!!! 4% is very harmful over long period of time and 10% will gurantee bore polishing!!! THis engine will not make it to 120,000 miles in sound order if this persists! [ August 13, 2003, 07:01 PM: Message edited by: JohnBrowning ]
 
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6,614
Location
southeast US
Some follow up to wrap up the topic. My dealer thought the car was fine. I was not convinced, I had oil analysis showing 3.9% fuel and smelled gas in oil even after the oil change and injector cleaning. However, I retested after 200+ miles of high speed highway driving with heavy load (total of 1000 miles on new oil) and 0% fuel this time. Also, the smell of the oil was different and oil level slightly lower. BTW, it took forever (=3 weeks) to get UOA results from oil guard lab. Clearly, my wife's Subaru accumulates fuel in oil in her short distance city trips (even in 90F temps) and it takes hours of heavy duty service to get rid of it.
 
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8,937
Location
SC
I can tell you how much an early 80s 454 in a Chevy pickup can stand: About three quarts. I have a good friend in another state who bought a new Silverado in 82 (I think) with the 454 in it. At around 15,000 miles he noticed that everytime he checked the oil, it was ABOVE THE FULL MARK. Rather than take the darn truck in to have it checked, he had his son just drain some oil off. They did this about four or five times before the engine started knocking and that's when he decided to take it in and have it looked at. It threw a rod on the way to the dealer. Turns out the diaphragm in the fuel pump (the old mechanical type driven off the crank or the cam) had developed a leak and was pumping raw gas into the crankcase. The mechanic that tore the engine down estimated that it had about THREE QUARTS of gas in the oil. It was thin as water and smelled like raw gasoline.
 
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8,937
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SC
Ken, the sort of driving he's described would cause fuel in the oil even in a perfectly tuned engine.
 

KW

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1,686
Location
Central Arkansas
quote:
Originally posted by friendly_jacek: However, I retested after 200+ miles of high speed highway driving with heavy load (total of 1000 miles on new oil) and 0% fuel this time. Also, the smell of the oil was different and oil level slightly lower. Clearly, my wife's Subaru accumulates fuel in oil in her short distance city trips (even in 90F temps) and it takes hours of heavy duty service to get rid of it.
My wife drives less than one mile to work, home for lunch, back to work, and home again five days a week. This is very hard on the oil so what I have been doing is going for a Sunday drive for about 50 miles or so to boil any fuel and water out. I'm glad to see this plan might be working. KW
 
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6,388
Location
Washington St.
quote:
Originally posted by KW:
quote:
Originally posted by friendly_jacek: However, I retested after 200+ miles of high speed highway driving with heavy load (total of 1000 miles on new oil) and 0% fuel this time. Also, the smell of the oil was different and oil level slightly lower. Clearly, my wife's Subaru accumulates fuel in oil in her short distance city trips (even in 90F temps) and it takes hours of heavy duty service to get rid of it.
My wife drives less than one mile to work, home for lunch, back to work, and home again five days a week. This is very hard on the oil so what I have been doing is going for a Sunday drive for about 50 miles or so to boil any fuel and water out. I'm glad to see this plan might be working. KW

But you are still not fixing the problem. There should be no fuel in the oil. Find and fix the problem. If one injector is dribbling fuel into the cylinder, think of how it's washing the oil film off the cylinder wall and how the wear is accelerating in that area. Ken Ken
 
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