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Engine Oil & 2 Ignition coils smell like gas

  • Newly acquired 2004 LX470 with 120,000 miles
  • No check engine lights are on.
  • Recently changed all spark plugs - I noticed that 2 ignition coils smelled like gas.
  • These 2 coils were also “burnt” and covered in a soot-like appearance. I didn’t replace any coils, but I did replace the all the rubber components: boots and gaskets.
  • Recently cleaned the MAF sensor and Throttle Body.
  • I replaced the engine oil today and it smelled like gas.
  • I do drive short trips (frequent 5 mile trips)

Are there any symptoms, like it doesn’t run well? Are there any dashboard warning lights on? Any diagnostic codes? Ignition coil odor isn’t diagnostic. Short trips can indeed cause small quantities gasoline to move into the oil system, and gasoline makes a strong odor, so that might be normal.

Ignition misses can cause the oil to have a gas smell. Check the fuel pressure regulator. Remove the vacuum line and note if there is any fuel smell in the hose. Suction can also be applied to the regulator. If the suction holds the regulator is good.

Needs to be sorted out. Gas is a bad lubricant and gasoline diluted motor oil will wear out an engine in short order.

I haven’t checked the evap for leaks but the hose didn’t smell like gas. There are no CEL lights on.

Today I got worried when the engine oil cap has a slight white residue.

I checked the spark plugs and all of them were undertorqued. One of the plug gaskets had a tiny amount of burnt oil seeping from it. The coils smelled more like oil this time. I tightened all plugs to slightly over factory specs.

It could be my imagination but idle feels slightly smoother.

Could loose spark plugs cause engine oil to smell like gas?

Only if they are loose enough to fall out

It basically untorqued with very little resistance. Well under 10 ft pounds of torque.

I’m at the dealership and they are recommending an “air fuel ratio “ reprogramming. Is this bunk or legit?

And there’s your problem, short trips don’t allow the engine to get up to proper operating temperature.
You need to go out for a 20 - 30 mile drive on the interstate once a week , or start changing your oil and filter every 6 months.

That’s a steaming pile of caca. The dealer can’t change the air/fuel mixture, and you’re looking for trouble where none exists. Just take some trips on the highway longer than 20 minutes. That will get the oil hot enough to drive out the gasoline. And be sure and change the oil on the " severe " schedule.

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The engine oil dipstick does not smell gassy. When I rub the oil with my fingers, I don’t smell any gas. (Granted, the oil was freshly changed yesterday)

It’s the oil cap that smells like gas. I think I’m good!

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But how did the oil smell that was drained out yesterday?

The old oil smelled gassy.

I strongly suggest that you check your oil often and immediately change the oil if you find it smells like gasoline again.

I’ve read that small amounts of gas in oil is fairly common. Is this accurate?

My new oil is now smelling like gas after 500 miles.

Could new coils help? Some coils are covered with a burnt residue but I don’t know if they are damaged.

I don’t know how sensitive your nose is but I’ve changed an awful lot of oil on a great many vehicles and it has been very rare that I smelled gasoline when draining crankcases.

I’ll suggest that you remove the spark plugs and inspect for black carbon buildup indicating an over rich condition and if you find that on all cylinders investigate the MAF, temp sensors and fuel pressure. If only 1 or 2 show a problem faulty(leaking) injectors are the likely problem. If all the plugs are clean it is likely that short trips and cool weather are the likely cause. But when I smell gasoline on the dipstick I change the oil immediately.

And posting here indicates you are paying attention, concerned and hope to avoid a costly problem so you can likely straighten things out before any serious problems occur.

Well, the plugs are 2 months old. At the time I didn’t have a torque wrench and this was my first time ever replacing plugs.

When I reinspected them last week, many of the plugs were very loose and under torqued. This time, I went slightly over FSM specs.

Can loose plugs cause gas to leak in oil?

Could you expand on this please? The plugs came out with a very loose half turn - I estimate at less than 5 ft. The FSM wants it at 13 ft.

If the seal ring was crushed it was sealed.

Does the ring look crushed in these photos?

Not to me. Compare with a new one.