Oil smells like Fuel

[CavScout]

Like it says, my oil smells like gas. After we did a head gasket change, an oil change was executed. Originally replaced because we thought the smoke puffs from the valve covers was antifreeze getting into the combustion chamber, it was. However the smoke continued after the repair, only worse. To ensure it wasn't coming from the turbo, we disengaged the Intercooler. We flushed the block and radiator and refilled with straight water so it can't be the coolant. That left oil, so we pulled a bit from the pan and dang it if it don't smell like gas. I don't think a Sy has a mechanical fuel pump, so how is it getting in there? She smokes out both valve covers (with PCVavles out) and some from the tail pipe. I have also done a cooling system pressure test and it is fine, but I haven't done a compression test or a fuel system check. Both will be done tomorrow. Any help, greatly appr. MANY thanks go to Mike Hood, good ol' boy from South Ga.

 

[Sy769]

Do the compression test. I have my suspicions but it will eliminate several possibilites

 

[CavScout]

You think it's the piston rings? On a personal note, where is that in Big Texas?

 

[Jimmy]

The diaphram in your fuel pressure regulator is broken and dumping raw fuel into the motor,probably.

 

[CavScout]

Although I didn't replace it, the fuel press. regulator is one of only 2 non-stock parts on the truck. It and the exhaust. I'm fairly certain it's not bad, yet. But we'll find out in the morn. Thanks Jimmy

 

[once again its on]

A broken diaphram will not dump fuel into the motor. It will just hold no pressure at the rail and allow it all to dump back into the return line to the tank. Do a compression check like dude said and should eliminate some questions.

The diaphram in your fuel pressure regulator is broken and dumping raw fuel into the motor,probably.

 

[Jimmy]

A broken diaphram will not dump fuel into the motor. It will just hold no pressure at the rail and allow it all to dump back into the return line to the tank. Do a compression check like dude said and should eliminate some questions.

The diaphram in your fuel pressure regulator is broken and dumping raw fuel into the motor,probably.

My diaphram was cracked and filled the crankcase with 5 gallons of fuel.It may have just washed past the rings,but that is the reason my oil smelled like gas.

 

[jwaller]

the diafram will put fuel into the motor. bc the vac line thats attacted to it will draw it in. also when you pressureizesd the fuel system with engine not running it will run up the vac line into the intake.

 

[once again its on]

What else can break inside an adjustable FRP to cause pressure not to hold at the rail? I know I've had two that have "broken" and not hold pressure; took them apart to see no tears in the gasket; and no fuel leaking into the motor. My Acufab is acting up; have to play with the screw; something happens & pressure holds again-WTF?

Anyways- learn something everyday I guess.

 

[CavScout]

But what we can't understand is how a bad fuel press. reg. gets gas into the oil, unless one or more of the injectors are leaking, right?

 

[jwaller]

if you cant hold FP then it can be the reg then again it can be the FP. either one can mess things up....you need to pinch off the return line from the FPR to see if you FPR or you FP is leaking down the pressure....

or it could even be a sticky injector....

 

[CavScout]

Alright, Mike Hood explained the pressure regulator vacuuming fuel up into bad places. Now, how would the fuel pump do this? We only have an electric pump at the tank, right? I fit was a mechanical one on the side of the motor, I could see where it could cause this, but since we don't....?

 

[sytyguy]

John was saying that it could be the regulator or the pump (or an injector) if the system can't hold pressure. There's no way that the fuel pump (by itself) can get gas into the engine unregulated. I would try the vac pump method (with key on) I described to you in the e-mail to isolate the FPR. If nothing comes up, try a comp test.

Michael

 

[Daron]

There are 2 sides of the fuel pressure regulator. One side has Fuel pressure, the other has vaccuum/boost, separated by a diaphram. If the fuel side starts leaking into the vacuum side, mucho gas will end up in your combustion chamber and wash past your rings, down into the crankcase.

 

[CavScout]

Thanks guys, all testing has been postponed 'til Saturday, when Uncle Sam says I get my time off. I will post the results.

 

[sharky207]

Sounds like it could be a leaky injector

 

[CavScout]

Yeah, my cousin David thinks so, too. Lord, I hope it ain't the rings. I just had the heads off for a gasket change.

 

[CavScout]

Ok, 3 tests completed and only 1 part broke on us. Not bad.

Fuel pressure test: 35 psi just before starting, but when we did start it, the o-ring for the oil filter remote adapter blew. Oil everywhere. Repeatedly cursed truck. Bought replcement, installed, refilled oil. Started truck, 35 psi while running. Turn truck off, 35 psi held for 6 min and only dropped 1 lb. I think I'm supposed to have the fuel at 43 psi, right?

Applied vaccum to AFPR line while the rails were still at 35 psi, and no fuel came out.

Cooling sys. pressure test at 15 lbs, all fine there. The cap needs replacement, no biggie.
I've decided to change the oil one more time to see if it helps. Did not get to do a leak-down or a compression test, but we will. Other than the rings, I've run out of ideas.

 

[leroy]

A faulty coolant temperature sensor can cause it to run rich.

Jim

 

[CavScout]

The one in the intake manifold or the one in the block?

Could water in the fuel be another cause? I've ony used 93 Octane, but then I am her 3rd owner.