Oil smells like gas... - Toyota 4Runner Forum

zazzomicron · 12-06-2019, 09:15 PM

Just rolled over 350,000km and did an oil change. I am continuously amazed by this engine. I put in 5.5Q last time and I pulled out 5.5Q! So I'm not burning an oil but the oil has a strong smell of gasoline. No cloud of smoke coming out the exhaust or anything either.

Should I be worried? Anything I should check/test? Not throwing any codes, MAF is clean..

spartacus · 12-07-2019, 12:20 AM

Quote:

Originally Posted by zazzomicron

Just rolled over 350,000km and did an oil change. I am continuously amazed by this engine. I put in 5.5Q last time and I pulled out 5.5Q! So I'm not burning an oil but the oil has a strong smell of gasoline. No cloud of smoke coming out the exhaust or anything either.

Should I be worried? Anything I should check/test? Not throwing any codes, MAF is clean..

Some minute amount of gas can get passed the piston rings and end up in the oil when the rings get worn down but it will evaporate when at operating temp. If it's a strong smell then it could indicate a rich fuel mixture which could be a bunch of things faulty injector, dirty MAF sensor, faulty O2 sensor, coolant temp sensor not working properly, damaged piston rings which is rare. Have you seen a drop in your fuel mpg recently. pull the codes via obd and see if you have any pending codes and look at air fuel ratio also if the coolant level is good.

pluton · 12-07-2019, 02:45 AM

A lot of short trip driving will allow the contaminants to build up in the oil...could be that.

BoomerBob · 12-07-2019, 11:50 AM

Quote:

Originally Posted by pluton

A lot of short trip driving will allow the contaminants to build up in the oil...could be that.

Very true. Short trips with a cold engine means the engine runs in a very rich condition much more per mile than, say, on longer commutes or trips. Some of that gas is bound to get into the oil.

I say monitor the oil but don't be concerned at this point.

negusm · 12-07-2019, 01:18 PM

He said "strong smell" of gas. I would do a compression check and pull plugs and see if anything is out of the ordinary.

JMat · 12-07-2019, 01:46 PM

Quote:

Originally Posted by zazzomicron

Just rolled over 350,000km and did an oil change. I am continuously amazed by this engine. I put in 5.5Q last time and I pulled out 5.5Q! So I'm not burning an oil but the oil has a strong smell of gasoline. No cloud of smoke coming out the exhaust or anything either.

Should I be worried? Anything I should check/test? Not throwing any codes, MAF is clean..

Since you said the truck has 350,000km I'm going to assume you're up in Canada. With cold temps this time of year engines have to run a lot longer to burn off moisture and small amounts of gasoline that find their way in to the crankcase... How far do you generally drive the Runner? Do you use it for short trips or stop and go driving? Also agree that a compression test would be a good thing.

Wedgy · 12-07-2019, 03:34 PM

Send some oil to Blackstone for analysis;
Free Test Kits | Blackstone Laboratories

19963.4lsr5 · 12-07-2019, 03:43 PM

In my experience gas smell in the oil in order.

1) dripping fuel injector or injectors when engine is turned off.

2) bad pre-cat O2 sensor. The sensor side hardly ever codes unless the heater circuit shorts to it.

3) very short trips and lots of them. Do you have a light coffee looking slime under your oil fill cap?

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zazzomicron · 07-09-2020, 12:10 AM

Hi everyone. Thanks for the responses!

Still dealing with this. I had a compression test and discovered a burnt valve.

I've also cleaned the MAF as it was filthy and this made a big difference. Next is O2 sensors..

19963.4lsr5 · 07-09-2020, 11:12 AM

Quote:

Originally Posted by zazzomicron

Hi everyone. Thanks for the responses!

Still dealing with this. I had a compression test and discovered a burnt valve.

I've also cleaned the MAF as it was filthy and this made a big difference. Next is O2 sensors..

You fixed the head I’m assuming?

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