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Oil reeks of gasoline

1996 Chevy S-10 2.2L, 83K miles

A couple weeks ago I posted about how my truck is getting harder to start, requiring several seconds of cranking before it fires up. A fuel pressure check revealed that it was priming up to spec, but quickly dropping off after that.

Lately I’ve found that if I allow the fuel pump to fully prime before cranking the engine, it tends to start easier. However, today I was changing the oil and upon removing the drain plug, I was hit with a strong stench of gasoline while the old oil drained out. I smelled my oily glove and the dipstick, and both also stank of gasoline.

My only thought for this is a really leaky fuel injector (maybe more than one), as I’m not completely sure how else fuel winds up in the oil. Could it be blowby from worn rings? Hard to figure that’d be the case at only 83K miles and religious maintenance. Any other thoughts as to how this is happening?

It could be leaky fuel injectors, but first you should check the fuel pressure regulator. It may be pouring fuel into the intake via the vacuum line attached to it. Once liquid fuel gets into the cylinders of an engine (while it isn’t running) it will wash down past the rings and into the crankcase. It can cause internal engine damage.

Probably should’ve mentioned it, but by all appearances the regulator isn’t a problem. I checked it previously and found no trace of fuel in its vacuum line.

I guess that just leave leaky fuel injector(s).

I read your other post, and it does seem to be a strong case for a single leaking injector. I bet you could find it by using a stethoscope to listen to each injector (put it on the injector body) while the fuel rail is pressurized.

I hadn’t thought of that. I’m guessing I would hear hissing or something similar?

That’s my thought.

For those who didn’t see my update in the other topic:

Replaced all the injectors today. It was definitely a faulty #1 injector; damn thing had a small crack in one of two tiny little holes drilled out next to the nozzle. The other three injectors looked fine, but all were replaced to be on the safe side.