Theta II 2.4 - straight fuel smell

Messages
411
Location
Los Angeles
I posted my OCI in the long thread, but my main question here is what I should do to mitigate fuel. With only 2700 miles/6mo on the oil, the oil was pitch black which I understand since this is the 2nd OCI from buying used (car was dealer mainted with bulk conventional, for 5-7k OCI, not ideal). However, the oil smelled like a gas can. I've never experienced something like this so it was quite concerning. I'm planning on sticking to max 6 mo/5k due to my severe usage. but should I consider running higher octane as well? I've been using 87 lately due to the higher prices in CA. I've used 91 and 89 before, and there is a slight power bump but wondering if its worth it to decrease fuel. I'm already running 5w30, so I don't want to go thicker due to lifetime warranty on these engines.
 
Messages
12,458
Location
OH
I’d go 6mos./4K miles with that engine and oil. Only way I’d go longer to 5k miles would be with an EP type oil with that engine.
 
Messages
6,228
Location
Texas Hill Country
My old Sonata would do this as well when I first got it.

You need to change the oil more frequently. Also don't be afraid of 10w30 with this one.

I believe the book is 3750 miles.

I could smell the fuel when I pulled the dip stick, but after a few changes it dissipated.

Also use the Hyundai/Kia filters on this engine, they are built for pressure spikes this engine is known for. They are cheap also.
 
Messages
7,576
Location
FL, USA
My old Sonata would do this as well when I first got it.

You need to change the oil more frequently. Also don't be afraid of 10w30 with this one.

I believe the book is 3750 miles.

I could smell the fuel when I pulled the dip stick, but after a few changes it dissipated.

Also use the Hyundai/Kia filters on this engine, they are built for pressure spikes this engine is known for. They are cheap also.
What type of pressure spikes?
 
Messages
1,575
Location
NE Oklahoma
These engines do not take to short trips very well. I agree with the 10W-30. In your climate, that shouldn't be a problem. I'd stick to no more than 6 months, and no, no "extended drain" oil will allow you to exceed that. Your problem isn't the oil breaking down, it's the oil being diluted. I'd also recommend trying to get it out and stretch its legs at least once a week. Maybe pick a grocery store further away or something to get it out and up to operating temperature on the weekend.
 
Messages
3,054
Location
pa
girfriends preowned 18 optima 2.4 does well on 6 mo 5 thou whichever comes FIRST + gets 10-30 Quaker state ultimate durability fake synthetic + OE filter in Pa + unlike her traded 13 malibu 2.5 it uses NO oil between changes + does a lot of shorter drives. a great car so far
 
Messages
2,016
Location
Crawfordville FL
M1 HM 10w-30 and 4K if the dilution is that bad. Premium fuel may or may not reduce dilution. You will have to try it and see. Your biggest problem is short-tripping. Drive for 30 continuous minutes once a week to cook some of the fuel out of the oil.

BTW smell is useful, but the only real way to know how much dilution you have is to get a lab UOA. If you don’t want to pay for UOA then be conservative with the OCI and change at/before 4k
 

haggler

Thread starter
Messages
411
Location
Los Angeles
M1 HM 10w-30 and 4K if the dilution is that bad. Premium fuel may or may not reduce dilution. You will have to try it and see. Your biggest problem is short-tripping. Drive for 30 continuous minutes once a week to cook some of the fuel out of the oil.

BTW smell is useful, but the only real way to know how much dilution you have is to get a lab UOA. If you don’t want to pay for UOA then be conservative with the OCI and change at/before 4k
Are there any 10w30s full syn with a HTHS of 3.5 besides M1 HM ? Don't care for swollen seals. I may consider that next time but I have 1 jug of kirkland and 2 jugs of RGT in 5w30.

Funny thing is i brought out the UOA sample bottle but it wasn't until after I pulled the plug and it drained for 5 min that I realized I forgot to sample it.
 
Messages
2,016
Location
Crawfordville FL
Are there any 10w30s full syn with a HTHS of 3.5 besides M1 HM ? Don't care for swollen seals. I may consider that next time but I have 1 jug of kirkland and 2 jugs of RGT in 5w30.

Funny thing is i brought out the UOA sample bottle but it wasn't until after I pulled the plug and it drained for 5 min that I realized I forgot to sample it.
I believe M1 ESP 5w-30 is HTHS 3.5

I’m on my phone at the moment so I can’t easily check
 
Messages
567
Location
California
The renewable lubricants oils are known for resisting fuel dilution. My last UOA had 8% fuel and still had normal wear rates with RL HD 10w30, which has an HTHS of 3.6.
 
Messages
37
Location
WestCoast
I posted my OCI in the long thread, but my main question here is what I should do to mitigate fuel. With only 2700 miles/6mo on the oil, the oil was pitch black which I understand since this is the 2nd OCI from buying used (car was dealer mainted with bulk conventional, for 5-7k OCI, not ideal). However, the oil smelled like a gas can. I've never experienced something like this so it was quite concerning. I'm planning on sticking to max 6 mo/5k due to my severe usage. but should I consider running higher octane as well? I've been using 87 lately due to the higher prices in CA. I've used 91 and 89 before, and there is a slight power bump but wondering if its worth it to decrease fuel. I'm already running 5w30, so I don't want to go thicker due to lifetime warranty on these engines.

It's far more common of a problem than you think with the 2.4L T2 engines. It's one of the sacrifices people take on to have the GDI engine.
 
Messages
3,155
Location
GA.
I’d go 6mos./4K miles with that engine and oil. Only way I’d go longer to 5k miles would be with an EP type oil with that engine.
+1 on the advice given by SatinSilver ... I have the same engine (Theta II 2.4L GDI) in my 2017 Sonata with the same soot , gas smell , etc. at the same mileage as you . For the 4K mile / 6 month OCI bump up to a 5W30 D1 / Gen 2 of your choice and in the warmer months a 10W30 is ok per the OM to use as well in that engine .
 
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