gas smell in engine oil?

Bacondoggy

Registered User
First off, I want to say thanks to 89XR7TD (Tom) - he came up to my house and helped me out big time! Really nice guy there! We got a 70mm TB, raised top and Double IC installed and running good! Noticed I have a gas smell in the engine oil though. Didn't get to put the APFR on... What would be causing this? leaky injector? Bad FPR? both??
 
Spanner nut was hand loose

Yo Mark, it was nice meeting you-your g/f-and parents yesterday!I'm glad I was able to come down and give you a hand. It seemed like everything went on smoothly:)

If it was my car we were working on everything would have went wrong:rolleyes:

Just wished we could have put on that fuel pressure gauge to check things out, those parts places didn't have the right brass fittings.

I'm sure you will be going to home depot this week since they have bigger selections:D

The 18"s were the finishing touch for yesterday and wheels make a huge difference eh, but next on the list should be that bad r/r bearing.

Oh yeah, change the oil and see if it smells like gas, although your car seems to run just fine other than the CEL comes on!

Tom
 
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first off, change the oil, if it smells like gas that means that it may be contaminated with gas and thinned out. The smell could be caused by too much blow-by, or a leaky injector. or some other condition causing too much fuel to be delivered to the cyl. you said it runs good so i guess you con't have a missfire. but a rich missfire could cause that
 
Blow By is a condition where combustion gases get past the rings of the piston and pressurize the crank case.....

A bad FPR could cause an increase in fuel pressure to the point where your injectors are operating at 100% duty cycle....

Have you had a chance to check your actual fuel pressure at the rail?

I had a 90 SC that was getting 90 psi at the fuel rail due to a crushed fuel return line near the fuel filter.....

I checked the oil and it was about 1½ quarts over and had a fuel odor in it....

Change your oil ASAP as the fuel will thin the oil out.....:eek:
 
Blow by, is material blowing past the rings in to the crankcase. Did you change the MAF also? I had the wrong size tube in once and caused the same problem you have, a bad FPR could cause this also, get a pressure gauge and check it at the rail.
 
I checked the fuel pressure at the rail a long time ago and I dont remember what it read I thought it was around 40, but that was not with the pump constantly running... I think I smelled gas when I took the FPR vac line off, but that wouldn't send gas to the oil, would it? My maf is stock right now... The rings/pistons were all new when the engine was rebuilt about 3000-5000 miles ago... When I looked at the oil, it seemed low. My car does not drip oil, but I saw some oil on the lower IC tube. At first I thought it was PS fluid, but now I am not so sure... arrgh
 
Some oil in the bottom IC tube is normal and doesn't necessarily mean that you have excessive blow by.....

45 psi at the fuel rail seems to be alright....

However, you could have a bad injector that is squirting raw fuel into the combustion chamber and it will run down into the oil pan.....
 
no - there was no oil IN the IC tube - I meant running down the outside. I need to re-check the fuel rail pressure. I don't want to change the oil though, only to foul up the new oil! grr. I guess best bet is to take the injectors to a dealer and have them checked/cleaned/whatever? Could a torn O ring on an injector do the same thing?
 
No, a torn O-ring on an injector would result in either:

A. A fuel leak to the outside of the engine (if it was the o-rings that go between the injector and the rail)

B. A vacuum or boost leak (if it was the o-ring where the injector fits into the head)

An injector could certainly leak or drip, but that is usually the result of contamination between the pintle and seat. You could pull them and get them checked out. A much cheaper and easier way to check it would be to do a fuel injector leak-down test with a fuel pressure gauge attached to the rail. You basically pressurize the rail by turning the key on and off a few times, then watch the gauge to see how fast the pressure bleeds off.
 
Slight gas smell

In the oil it had but didn't smell like raw fuel. Just so slight smell in there.

I told him it was normal to have a little bit of oil in the IC tubes.

So blow-by isn't the issue.

Yeah after you get the right fittings for that fuel pressure gauge hook it up and run it and shut it off and if the pressure goes down kind of quick then maybe leaky injector.

Tom
 
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