Gas in the oil

BoostedSUV

BoostedSUV

Active member
Not sure why I'm really asking this as I have my suspicions. I'm getting gas in the oil. The truck sits more than it's driven and pretty much every last part is new. Truck was completely rebuilt from the chassis up. I started noticing smoke at start up (smells like fuel) and I noticed my oil level got high and smells like gas.

I know for a fact when my truck gets hot it's hard to start. When data logging engine rpm reads 7000 (still cranking) and injectors go 100% firing fuel but it doesn't want to sart. I suspect (hope) this is my issue. However it may be possible I have an injector leaking down and the gas is working it's way into the pan. I noticed this a few months ago (high oil level) so I drained the oil and put fresh in it. Haven't driven the truck very much at all since then. Mostly just starting it to move it in and out of the garage. Today I went for a spin and as soon as I laid into it there was a smoke screen out the exhaust. Turned around, put it in the garage and checked the oil. The oil was half a quart high, a light brownish and smelled like gas.

Any other ideas? I'm going to pull the plugs and see of any are soaked with gas. Injectors have maybe 500 miles on them... Fuel pressure is good. I have an electric gauge so I can't see if pressure is leaking down. Just thinking out loud here.
 
C

Captain Morgan

Moderated User
Re: Gas in the oil

the only other thing I would suggest is to check the Fuel Pressure Regulator. I know some members have mentioned/found aftermarket AFPR diaphragms going bad and I have swapped out bad (leaking) OEM FPRs before too.

It seems logical that you have already found your problem, but it doesnt hurt to check.
 
Jimmy

Jimmy

Banned
Re: Gas in the oil

1000% FPR. Pull the vac line off it and smell.

Replace FPR,set pressure,change oil,hope the bearings are OK.
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Fpr would be an easy change. That is one of the "older" parts on the truck.

So I guess you're all thinking the fuel is going into the vac line and making it's way into the oil that way? I like that idea as it's easier than pulling injectors. Lol
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Jimmy said:
1000% FPR. Pull the vac line off it and smell.

Replace FPR,set pressure,change oil,hope the bearings are OK.
Click to expand...

Bearings should be fine jimmy. There's very fuel miles on the motor and I have been watching this issue as I will not drive it knowing there's gas getting into the oil.
 
Jimmy

Jimmy

Banned
Re: Gas in the oil

BoostedSUV said:
Fpr would be an easy change. That is one of the "older" parts on the truck.

So I guess you're all thinking the fuel is going into the vac line and making it's way into the oil that way? I like that idea as it's easier than pulling injectors. Lol
Click to expand...

Easy check.Pull vac line off and use a lighter to see if it has fuel in it. :D

J/K yes it's a very common prob that has blown up countless trucks.
 
Jimmy

Jimmy

Banned
Re: Gas in the oil

The vac line smelling of fuel is key. Otherwise it's the fuel pump prob.
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Thanks guys. I was thinking too in depth and overlooked the FPR. I will look Into that and hope that's all it is. Never have I had an "easy" fix with a typhoon! My fingers are crossed
 
Jimmy

Jimmy

Banned
Re: Gas in the oil

BoostedSUV said:
Thanks guys. I was thinking too in depth and overlooked the FPR. I will look Into that and hope that's all it is. Never have I had an "easy" fix with a typhoon! My fingers are crossed
Click to expand...

If the vac line doesn't smell then it's the fuel pump.

I don't know the technical jargon for the failure,but I do know that there is "something" in the pump that tells it that it has reached pressure,and if it fails the pump will just keep running trying to hit that pressure.
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Just ran out into the garage and pulled the vac line. No real overwhelming smell of gasoline? I let the truck idle and pulled the line off and didn't see any fuel pushing out the barb fitting either. 45psi with no vac line and 38 with the line on. I shut the truck off and watched the fuel pressure for a few minutes and it didn't drop off quickly or anything. I'm going to pull the pump fuse, turn the key on and check fp again in a little while.
 
Jimmy

Jimmy

Banned
Re: Gas in the oil

BoostedSUV said:
Just ran out into the garage and pulled the vac line. No real overwhelming smell of gasoline? I let the truck idle and pulled the line off and didn't see any fuel pushing out the barb fitting either. 45psi with no vac line and 38 with the line on. I shut the truck off and watched the fuel pressure for a few minutes and it didn't drop off quickly or anything. I'm going to pull the pump fuse, turn the key on and check fp again in a little while.
Click to expand...

Have the wife/boyfriend/neighbor smell the vac line.Dont say anything just ask her/him what it smells like.
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Going to check again in a little bit to see if it dropped off any. Might throw my mechanical gauge back on the rail to compare to elec gauge in the truck
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Now I'm wondering if this is my hard starting issue once the truck is warmed up vs vice versa.
 
Don W.

Don W.

Stab it and steer it
Re: Gas in the oil

I don't think it's the FPR, you've tested that. The FPR won't make the tach read 7000 or the injs go to 100%. Disconnect the bat. While it's disconnected check that chip and its board are fully seated. Make sure all the connectors to the ECM are seated.

Reconnect bat. What now?

What is the inj duty cycle once it starts? I cannot think of any way fuel can get into the crankcase other than the FPR or maybe a stuck injector. Does it have a miss?

If it is a stuck inj then that cylinder is being washed of oil. Harder on the rings than the bearings. Pull the plugs, what do they look like?

IIRC The injs are "hot" all the time, the ecm grounds them, 3 at a time, to fire them. A short in either of those wires would cause those injs to stay on.

Random thoughts
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

They may be unrelated issues Don. The hard start issue happens after driving a while. The tach doesn't actually read 7000. The ECM sees 7000 RPMs and fires fuel and the truck won't start. (If I watch cranking with datamaster) If I hold it wide open it will start and run a little rough until it clears out. This issue dates back to my old typhoon that I gutted, rebuilt everything and swapped into a new truck.

No miss, idles smooth. I pulled the vac line again (now that I showered and don't smell like gas myself) and there is a faint but definite gas smell in the vacuum line. Nothing that I wouldn't consider to be normal. It's not gas soaked or really strong though.
 
BoostedSUV

BoostedSUV

Active member
Re: Gas in the oil

Exactly 1 hour. Fuel pressure dropped from 40 psi to just over 10. How fast will pressure bleed off?
 
You must log in or register to reply here.
Top