Fuel contaminated oil

Digitalchaos

Registered User
After completing an oil change, there was strong fuel odor to the oil and the mechanic noted it looked unusually thin as when contaminated by gas.

What are some of the possible causes of fuel contamination in the oil?

I have also been chasing a starting problem; it manifests itself as moderately extended cranking time.

I know the fuel pressure regulator and leaking fuel injectors can cause this, what else? The car does not run rich during operation, though it sometimes does during a warm restart.

Thanks for your help..
 
the longer cranking would add to fuel not being burnt washed down into the oil maybe new plugs would fire quicker , mine ran rich when fuel pressure was low pump was going bad my connector on the top of the tank was melted away to nothing i think that was the problem more than the pump
 
I checked the regulator and found no evidence of failure.. so I guess this can be eliminated.

Rlong, you say the gas contamination could simply be the result of longer crank times? I was thinking the longer crank times might be the result of gas in the cylinder after shutdown, from either FPR or injectors.

Any more input is welcome, I will attempt to run Chevron Techron later tonight.
 
fuel problem

I have same problem with extended cranking, I'm all most certain its a leaking injector. My 89 is 200 miles on a rebuild I replaced everthing, fuel pump, water pump , oil pump, all sensors and senders, fuel regulator,starter everythng but the stinking (150g miles)injectors, I had run completely out of money.I was having a problem of stumbleing under boost, I found a cracked plug, but also three cylinders that the plugs were gas saturated.
 
Recently I have had significantly less trouble with this. The weather has been warmer, but mainly the change has come after 2 bottles of Techron.

At first I didn't think it worked, but now I have had more time to observe any differences. Cranking warm and cold is less labored/shorter, and I am getting significantly better gas mileage. At the current rate, I might actually get close to 400 miles on a tank around town :eek: .

The future holds more...
 
bad injector

Digital

I just finished changing out my injectors, it cleared up all my problems. No more long starts, it cranks instantly now. Mine was leaking bad I would get almost an extra quart in crankcase in less than 30 miles...it never crossed my mine that the long strats was from a leaking injector.
 
That is a lot of gasoline in your crankcase :eek:

I haven't seen any oil increases or similar yet, however it is still getting relatively dirty.

At this point I'm sure its the injectors, just looking for a way to service them that does not require disassembling my engine, like through the use of a fuel rail attached cleaner.
 
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