Oil Smells like Gas after using Injector Cleaner

[cryptolyme]

I have a 2023 Honda Civic Si with the 1.5 GDI turbo engine. With the factory fill, I noticed zero gas smell in the oil up until 7700 miles. The dealership changed it with Valvoline synthetic. I used some Liqui Moly DIJectron at 8000 miles and shortly after noticed my oil now smells like gas. Is this related to the oil or the injector cleaner?

I have heard that Honda's oil is actually a synthetic blend which helps with oil dilution in these engines. Any truth to this? Should I be using a synthetic blend?

 

[Jetronic]

Did the first 8000 miles happen during warmer weather?

 

[wpod]

How would a certain oil help with fuel dilution? Why did you use injector cleaner?

 

[cryptolyme]

Did the first 8000 miles happen during warmer weather?

a bit warmer. I'm in coastal North Carolina so it doesn't get that cold here. coldest it's been is about 45 degrees.

 

[cryptolyme]

How would a certain oil help with fuel dilution? Why did you use injector cleaner?

I don't know, that's why I'm asking. I've heard conventional oil helps the rings seal better. I used injector cleaner because I want to keep my injectors clean. They have been known to fail around 75k miles in these engines. Before I used it i was about about +6% on my LTFTs. now I'm at 0.

i know these engines are extremely thermally efficient and struggle to get up to operating temp in colder weather.

 

[KrisZ]

If the long term fuel trims went down, then that would indicate less fuel usage and that the injector cleaner worked. Therefore it cannot be the cause of fuel smell in oil.

 

[cryptolyme]

If the long term fuel trims went down, then that would indicate less fuel usage and that the injector cleaner worked. Therefore it cannot be the cause of fuel smell in oil.

alright, hopefully the gas will burn off after i do some hard driving today

 

[Cujet]

In general, it is advised to use injector cleaner shortly before an oil change. As some fuel (now with cleaner) will get past the rings and into the oil. That way, any residual chemicals are drained with the oil.

However, on my Jag F-Type, the injectors are known to stick, and regular cleaner use solves the problem. I use it anytime. The injectors are not expensive, but changing them can be a real problem, sometimes requiring cylinder head removal.

As for synthetic blend being better for fuel dilution, not likely. I can not think of a time where lower quality oil performs better.

 

[cryptolyme]

drove it about 60 miles on the highway today and kept it above 3k rpms. still smells like gas. oil is right the max oil level on the dipstick. now seeing -1 LTFTs.

 

[KrisZ]

That engine has a fuel dilution problem, especially in cold weather. There is nothing you can do about it except bum up the viscosity and change the oil sooner. There is nothing else you can do unfortunately, you will have to learn to live with it.

 

[meep]

Congrats on the civic Si, wonderful car. We had the sport version in a 2018 with the 1.5T and 6mt. A couple of notes.

ours did exhibit some fuel dilution early but settled down with miles. We started using half 5-20 and half 5-30, and maybe more towards 5-30 as it got some miles on it. Ran great, ran hard, never missed a beat, and we followed the oil minder. If you wanna go full bore, just change it every 5000 miles and that alone will help a lot - but I certainly suggest going up a grade and mixing that in, and then not worry about it.

besides that, go easy on the cleaners and chems, just use good gas and enjoy the vehicle. ours was a great car.

 

[cryptolyme]

Congrats on the civic Si, wonderful car. We had the sport version in a 2018 with the 1.5T and 6mt. A couple of notes.

ours did exhibit some fuel dilution early but settled down with miles. We started using half 5-20 and half 5-30, and maybe more towards 5-30 as it got some miles on it. Ran great, ran hard, never missed a beat, and we followed the oil minder. If you wanna go full bore, just change it every 5000 miles and that alone will help a lot - but I certainly suggest going up a grade and mixing that in, and then not worry about it.

besides that, go easy on the cleaners and chems, just use good gas and enjoy the vehicle. ours was a great car.

how many miles did it take before the dilution settled down? It's odd that I had zero gas smell with the factory fill. Might try using genuine Honda oil on my next oil change.

I was aware of the oil dilution issues when I purchased it but just want to make sure nothing is wrong with the engine. I broke it in properly and have brought it up to redline a couple times after the break-in period.

 

[oil pan 4]

Welcome to the world of direct injection engines.

 

[wavinwayne]

Not directly related to OP's issue, but it reminded me that my old '00 VW GTI 1.8T oil always reeked of gas, but UOA never showed fuel dilution.

 

[Cherrybomb]

Welcome to the world of direct injection engines.

Honda has had a problem with fuel dilution in these engines.Get on the Honda Forum for more comments. You should probably do an oil anaysis at about 5,000 miles thru Oil Analysis Labs.They wiil give you numbers on your fuel dilution.If it is excessive it will tell you ,to probably change your oil more often.Fuel in the oil takes dilutes the lubrication properties and causes premature wear,not a good thing.As far as injector cleaning goes,if you fuel at a Top Tier or other reputable station you shoul be good.Short trips are definitely hard on direct injection engines

 

[meep]

how many miles did it take before the dilution settled down? It's odd that I had zero gas smell with the factory fill. Might try using genuine Honda oil on my next oil change.

I was aware of the oil dilution issues when I purchased it but just want to make sure nothing is wrong with the engine. I broke it in properly and have brought it up to redline a couple times after the break-in period.

If I recall it seemed to settle pretty well around 15-16k miles. Now, he drove it hard all that time with plenty of high rpms and lots of throttle, so it wasn’t babied. and that’s also about when I started adding in thicker oil just because he drove it how a manual civic should be driven. my best advice is to not overthink this too much - the internet will use wording that may be stronger than is needed. I’m pretty sure this engine will hit just over 16psi of boost, stock. Thats not a lightweight. Yes, a turbocharged mill running a lot of pressure has more propensity to do this. And the result is also a drivetrain that has so many great manners and abilities - like all the power AND all the mpg - and at least in my experience, changing slightly more often with a slightly thicker grade worked out well and we stopped worrying about it.

 

[cryptolyme]

drove about 3 to 4 hours yesterday and today and the oil level has gone down to where it was when i got my oil changed 1000 miles ago. right in the middle of the low and high points. was about 1 mm above the high point yesterday morning and it reeked. still smells a little bit like gas but much less so. so that's good news. at least it's not steadily going up. appears to be burning off. i did a high rpm pull last week and hit fuel cut so maybe it dumped a bunch of fuel into the cylinders when it cut spark.

 

[Cujet]

drove about 3 to 4 hours yesterday and today and the oil level has gone down to where it was when i got my oil changed 1000 miles ago. right in the middle of the low and high points. was about 1 mm above the high point yesterday morning and it reeked. still smells a little bit like gas but much less so. so that's good news. at least it's not steadily going up. appears to be burning off. i did a high rpm pull last week and hit fuel cut so maybe it dumped a bunch of fuel into the cylinders when it cut spark.

It won't dump fuel while cutting spark. The opposite is what sometimes happens with some programming, fuel is cut, but spark continues. However, on most modern engines, the need to keep the catalyst hot requires that the engine continue to fire.