Gas smell in oil.

[xb1230]

Sorry for the long post, but as this a troubleshooting question, I want to make sure I provide as much information as possible to get the best possible help.

My oil smells gas after only about 1000~1500 miles.

I did google this and found a lot of info, but not necessarily related to the 4.7L or any other Dodge engine per say which is why I am posting here.

• The dipstick does not burst into flames if placed over a flame, my engine idle is quite smooth, the engine and/or injectors don't tick even when cold.

• I have no CEL, no DTC codes

• Both my O2 sensors have been replaced

• TB/IAC cleaned, and TPS checked.

I try as much as possible to not stop the engine before I have driven it to operating temp for at least 15 minutes, to prevent condensation as much as possible, but I have short drives of a few miles to deal with very often, and weather has been brutally cold (average of -12°F) in my area for the past few weeks.

Even in these brutally cold weather the truck starts on first crank, leading me to believe I don't have fuel system pressure issue or leaky injector, but I am not completely writing this off the board.

The only thing that is torturing me over this is the somewhat low fuel economy (High Gas consumption) I have been having since I got the truck last year. This persists, even though I now have a SCT3842 and run the Mileage XS tune which has helped in slightly increasing the MPGs(I average 14MPG on the highway while most do 17 without the tuner...).

When cold, everyone here complains the truck smells really bad (like a old carbureted V8 with a stuck choke...). It gets better with the engine running at normal operating temp but still is not perfect.

Right now I dump the oil and filter as soon as it starts smelling to ensure I don't have too much gasoline in the oil to break it down and cause internal engine damage.

My next steps are:

• to do a compression test,

• Cylinder leak down test,

• and fuel pressure/leak test,

to validate I don't have an issue with the fuel system dumping gas in the engine while it's cooling off, or any issues with the heads, head gaskets, valve seats or something else.


Questions:

1. should I be worried or considering the weather factor this is expected?

• Anything else you feel I should do to even if as a safety/preventative measure?

• Anything else you would check if the above troubleshooting steps do not reveal anything?

 

[charonblk07]

I would bet you've got an injector that's flooding a cylinder or two and it's running down the walls into the oil. I'm having the same issue at the moment and have a couple of injectors that need to go in.

 

[JPT]

Are you sure it isn't normal? Every car I have ever owned has had a smell of gas in the oil.

 

[xb1230]

Are you sure it isn't normal? Every car I have ever owned has had a smell of gas in the oil.

As I mentioned in my original post I am absolutely not sure of anything at this point. But yes it could be very normal. I guess a used oil lab analysis would be a good thing to know if everything is normal.

I would bet you've got an injector that's flooding a cylinder or two and it's running down the walls into the oil. I'm having the same issue at the moment and have a couple of injectors that need to go in.

Wouldn't the engine be hard to fire up if I had leaky injectors? It just starts right up after I press on the starter even in the currently deep cold weather we are having around here. Heck -34°C yesterday and it started as well as if it was 20 above...

I guess I would have to stick a fuel pressure tester on the rail to really know if there is a leaky SOB.

Not having the previous owners history on the vehicle doesn't help in regards to where everything is...

 

[xb1230]

If the piston rings would be stuck in sludge in the grooves, could that explain some gas leaking into the oil? But I guess it would also expose some major compression issue and other problems...

 

[charonblk07]

Wouldn't the engine be hard to fire up if I had leaky injectors? It just starts right up after I press on the starter even in the currently deep cold weather we are having around here. Heck -34°C yesterday and it started as well as if it was 20 above...

I guess I would have to stick a fuel pressure tester on the rail to really know if there is a leaky SOB.

Not having the previous owners history on the vehicle doesn't help in regards to where everything is...

Not necessarily, my issue only crops up under part throttle and WOT, I can tell by the AFR dropping into the 10s on the passenger-side bank. If it's leaking it never has to be much or could be a drain down issue after the engine's turned off and the fuel rail depressurizes faster than normal. At that point fuel would run down the cylinder wall past the rings but have a clear cylinder for start up. This is all conjecture though until you do some diagnosis.

 

[xb1230]

I'll be heading to the DIY garage this week to replace all 4 front Ball joints and if time permits my front hubs. If I have some more time I'll try and throw the fuel pressure tester and see if or how fast the pressure drops when I shut the engine off.

Thank's for the tips.