Gas in oil smell? 89 Renix

[Ecomike]

Jeep runs fine, daughter 1000 miles away said she smelled gas odor at rear of the jeep last night. She checked the oil dip stick and she says it smelled like gas, and just now before firing it up still had SOME gas odor in the oil.

She just checked the gas tank lines / rear axle area after a short drive and it was bone dry.

Her nose is not yet calibrated , and we have already mapped a plan for her to replace Splugs and wires.

That leaves the question of a possible injector issue, but the oil is not thinned out, pressure is real good, 30-50 PSI idle to cruising and running 15W40 in the summer In Col, with 280,000 miles. Runs 10W30 in the winter.

So I am thinking partly tail pipe issue, bad cat converter (thus gas smell idling) and or maybe too many missfires on average making the oil smell some.

But the idle is perfect, smooth, no running issues. So I doubt a fuel injector issue. Starts up supper fast.

So I doubt it is fuel injection issue.

FWIW, I can smell a tiny gas leak two driveways away from me, I suspect she can too. So we may be over reacting.

Any thoughts???? Feedback???

 

[Black1990jeep]

Id get it diagnosed and repaired as needed ASAP.

Excess unburnt fuel in the exhaust is a quick way to destroy a catalytic converter, melt it, crack it, till it clogs the exhaust even. Pricey replacement.

Excess, unburned fuel tends to wash down cylinders of oil, resulting in rapid wear of bores, rings, and pistons. Gasoline in oil degrades its lubricating ability, too much and rapid wear sets in on bearings and such. Even with "good oil pressure" contaminated oil won't lube as well as uncontaminated oil. Do not depend only on good pressure as a gauge for assessing the protective properties of oil against wear.

driving with unburnt fuel in exhaust wastes money by gasoline mileage reduction, a potential cheap simple fix can cost many many gallons of gasoline if ignored.

Depending on what the problem is, the jeep may be very unreliable until corrected. Is a spark miss the first sign the distributor signal is getting lost with a bad connection almost ready to totally fail? What's the price of one tow? Leaving daughter stranded?


For the above reasons, get it fixed asap.

Good Luck!

 

[Mike Bonnell]

Just went through the same problem eded up being the fue pressure regulator

 

[Mike Bonnell]

I’ve got a 96xj mines part of the fuel pump on an 89 its on the fuel rail

 

[Ecomike]

Thanks Mike, I knew I was missing one possible fuel source, the FPR on Renix and HOs up to 95 (IIRC).

But I can rule that out as a leaking FPR screws up the idle and it has non of the other typical leaking FPR signs. I think it was checked a month ago....

I will however (just clicked) have her check the O2 sensor data to see if there is any sign of it running rich.

I know from 45 years of experience that a 30 year old DOA cat could be most of the problem (exhaust odor), and it is in an exempt county where it would never have gotten caught.

I will add one more possible issue and that is poor air flow in the Renix CCV scrubber line, small orifice and CCV Crank Case vent line on the back of the valve cover. I sent her a new CCV set, but she may not have had time to install it.

Just went through the same problem eded up being the fue pressure regulator

 

[Mike Bonnell]

Mine was idling fine to I have a rebuilt motor great compression new bocsh 4 hole injectors and new spark plugs I replaced everything changed out the fuel pressure regulator gas in my oil issue went away

 

[trippled]

How long has that oil been in there? If been 3000mi and it's got a hint of gas to it maybe that old motor just has some blowby diluting it some. Then again if it's got 500mi and reeks of fuel there's a problem. One of the ways we checked fuel dilution on diesels was to dap a drop of oil on a paper towel. And let it sit a few minutes. The oil will wick it's way out and the fuel would wick out a bit further, leaving a different colored ring around the oil. Idk how well it'd work with gas but easy to try.

 

[alexgalexg]

I remember on my 99 I had an issue in 2008 where if the tightener for the fuel pump wasnt abusively tight it would smell like gas at the back of the jeep. Maybe due to age of your weather stripping it seeps into the cab?

Sent from my SM-G950U using Tapatalk

 

[akelts]

Following. having the same issue in my Renix. Idles fine and drives fine but oil smells of gas. Just did a new exhaust manifold and gasket, new O2 sensor, cat and muffler too. Wondering if mine is due to the fact I usually only use it for short drives around town?

 

[Ecomike]

Chromatography is an interesting idea, but a friend of mine said use a lit :shiver:match LOL. Sounds like a real plan to me? Oil and filter gets changed about every 8-10 weeks on it, it gets about 200 miles a day, 3-4 days a week.

I have had the oil smell a little bit like gas before, for years with no problems. The problem is I have no way to sniff test with my calibrated nose being >1000 miles away LOL.

How long has that oil been in there? If been 3000mi and it's got a hint of gas to it maybe that old motor just has some blowby diluting it some. Then again if it's got 500mi and reeks of fuel there's a problem. One of the ways we checked fuel dilution on diesels was to dap a drop of oil on a paper towel. And let it sit a few minutes. The oil will wick it's way out and the fuel would wick out a bit further, leaving a different colored ring around the oil. Idk how well it'd work with gas but easy to try.

 

[Ecomike]

My gut feeling is that it may be the CCV lines (rear one) and poor valve cover seals...., and the CCV orifice on the rear being partly blocked, or not large enough, combined with increased blow by (engine age), a few more missfires than a new engine, building up just enough ppms of gas in the oil to smell.

Oil pressure would drop rapidly in my experience were there any real amount of gas in it, and getting below 13 psi is very bad!!!!

We should all run volt meter tests using the O2 sensor test thread here from about 10 years ago, to see how the exhaust looks. If it was an injector issue the O2 sensor might tell us. But a leaking injector should foul up the smooth idle I think.

Following. having the same issue in my Renix. Idles fine and drives fine but oil smells of gas. Just did a new exhaust manifold and gasket, new O2 sensor, cat and muffler too. Wondering if mine is due to the fact I usually only use it for short drives around town?