Fuel smell on dipstick. Possible causes?

[Snail’s Pace]

This is more of a general question regarding how things work with the 3.0L Vulcan engine rather than specific to the high-mileage (233k), poorly-maintained particular engine in the 2002 Ford Ranger with which we’re dealing.

Smelled gasoline on the oil dipstick. This concerns me because i had this happen on my ’81 Dodge van with a Slant 6 engine. That much older engine is carbureted and has a mechanical fuel pump attached to the engine block. The fuel pump diaphragm can leak, allowing fuel into the crankcase, creating what can be a bomb, as in the KABOOM! kind.

The 3.0L Vulcan is fuel injected with an electric fuel pump far from the engine block, so the failure won’t be the same.

Question 1: What are the possible failure modes for this engine whereby enough fuel could wind up in the crankcase to be smellable on the oil dipstick?

Question 2: Is this truck safe to drive in this condition? Or is it a potential rolling KABOOM! bomb?

Thanks!

 

[franklin2]

You will always get a little bit of fuel in the engine crankcase from blow-by. More on a high mileage engine. The PCV system should be sucking most of it out. If it gets really bad from a stuck injector, you may get O2 codes, since the computer see's a rich condition because of the fuel fumes messing up the air to fuel ratio. If you are not getting any codes, then the problem you have must not be anything to worry about.

 

[rusty ol ranger]

Unless you have an obvious rich condition (poor running, black smoke, flooding) i wouldnt worry about it.

 

[19Walt93]

If the oil smells of gas at least change it, drive it a little while and keep checking for gas. A leaky injector could be at fault, among other things. How does it run? Gas is a poor lubricant, don't ignore it.

 

[Snail’s Pace]

Thanks for all the responses. The truck/engine runs pretty well, especially considering its history. No O2 codes. Last i checked (June), just P0305 cylinder 5 misfire.

There’s a long back story on this truck which really belongs in the introduction thread. I’ll try and type it up soon if possible. Back in June the day i was doing a compression test on it (before researching and asking questions here), a medical emergency hit, aftereffects of which i’m still dealing. I’m well over 1000 miles away from the truck. My Love, the truck’s owner, is currently with the truck, would prefer to drive it vs. other options, has no time to work on it, and wants to know if it’s safe to drive as-is around town and occasional ≈50 mile highway + city round trips for the next couple of weeks.

There are some “big picture” questions related to the general (lack of) health of this truck and whether it’s worth putting more money into, given its poor maintenance history, but that’s for later when my Love and i can actually deal with fixing or selling the Ranger. Right now we’ve got other more urgent life stuff to deal with, so we’re trying to figure out if we can safely use it as-is for a little while, hence this discussion topic.

 

[19Walt93]

Change the oil and run it. Just check for a gas smell after a while.

 

[superj]

yup, change the oil and drive. jsut check the oil regularly.

where is the truck at? where are you at? maybe someone local can go check it out for you guys?

 

[Blmpkn]

A compression/leak down test might tell you something.

If an injector is leaking it should show itself while trying to start the thing with the gas pedal flat to the floor.