2015 Honda Civic 1.8L - 6878mi OCI - Castrol GTX FS & Supertech 0W-20

[OneLonelyBurrito]

Another year has gone by, that means another oil change and UOA completed on my Wife's 2015 Honda Civic. Same as last time, the OLM was showing 10% left again. The oil in the analysis is 50/50 mix of Castrol GTX FS and Supertech 10k version both 0W-20. This car is mostly short tripped, so not super surprised the fuel dilution didn't come down, as I didn't really do anything to try and lower it. But at the same time, this engine, the R18Z1 is port fuel injected, so you would think it wouldn't be prone to fuel dilution. But it may be more the way its driven in combination with the CVT always trying to be low in the RPM range that makes it more prone to fuel dilution.

Wear metals did improve this go around and even with the fuel dilution, the viscosity is still in the correct range. Based on the TBN, Oxidation, and nitration values, the oil appears to still have some life left. Not a lot, but some. Pennzoil Platinum 0W-20 is what is in the sump now, my plan is still to follow the OLM. I will plan to send another UOA in at the next oil change, which will probably be summer 2025.

 

[The Critic]

Annual oil change with a 6K interval? PA climate, so I assume some idling in cold weather to warm-up?

 

[Hall]

That fuel dilution level suggests a mechanical issue, doesn't it ?

They list the capacity as 4 gallons, which is 4x higher than actual. Are their numbers off by that ratio as well ? And what do they mean by the unit being new ? Engine been replaced ?

 

[The Critic]

That fuel dilution level suggests a mechanical issue, doesn't it ?

Not at all.

 

[OneLonelyBurrito]

Annual oil change with a 6K interval? PA climate, so I assume some idling in cold weather to warm-up?

My wife doesn't idle it a ton. She basically starts the car, getting her music setup and then starts backing out. Her commute is a little under 6 miles to work but mostly down hill so the engine definitely doesn't warm up since it doesn't need to power the car down the hill.

 

[OneLonelyBurrito]

That fuel dilution level suggests a mechanical issue, doesn't it ?

They list the capacity as 4 gallons, which is 4x higher than actual. Are their numbers off by that ratio as well ? And what do they mean by the unit being new ? Engine been replaced

I don't think its a mechanical issue, the engine doesn't show any signs of problem and still returns decent fuel economy for how she drives it.

In regards to the sump capacity, something must have get messed up when I submitted my sample as it should be 4qt. But I don't think it should matter for sampling purposes.

 

[cptbarkey]

Check your air filter and air filter box for leaks. Silicon should not trend upwards.

 

[OneLonelyBurrito]

Check your air filter and air filter box for leaks. Silicon should not trend upwards.

I had checked it last time, but couldn't find anything. I did replace the air filter with this oil change, so we will see if that helps.

 

[SatinSilver]

Good candidate for a 6 month oil change with the short trips and fuel dilution. Have you noticed the oil level rising on the dipstick? Even changing with Supertech 5w30 synthetic every 6 months is probably better than a year on something else. Then do another uoa after 6 months.

 

[OneLonelyBurrito]

Good candidate for a 6 month oil change with the short trips and fuel dilution. Have you noticed the oil level rising on the dipstick? Even changing with Supertech 5w30 synthetic every 6 months is probably better than a year on something else. Then do another uoa after 6 months.

It probably would be better to do 6month oil changes, but I think just gonna stick with the OLM or 1 year for now. Maybe at some point I will change to 5W-30 but for right now I will continue with 0W-20 since both vehicle take 0W-20. But I have never seen the oil level rise, it burned probably about 0.5qt over this oil change.

 

[Hall]

I had checked it last time, but couldn't find anything. I did replace the air filter with this oil change, so we will see if that helps.

Check the intake tubing. Around that era (and maybe others), it's pretty common for the rubber to split from pushing and bending it in order to open up the air cleaner box. It can be small enough to suck in debris but not big enough to trigger a check engine code.

 

[The Critic]

Check the intake tubing. Around that era (and maybe others), it's pretty common for the rubber to split from pushing and bending it in order to open up the air cleaner box. It can be small enough to suck in debris but not big enough to trigger a check engine code.

Yep, and that intake tube is kinda annoying to replace.

 

[OneLonelyBurrito]

Check the intake tubing. Around that era (and maybe others), it's pretty common for the rubber to split from pushing and bending it in order to open up the air cleaner box. It can be small enough to suck in debris but not big enough to trigger a check engine code.

Yep, and that intake tube is kinda annoying to replace.

I will take a look at the intake hose when I get a chance and report back.

 

[fantastic]

They flagged Aluminum but not the previous sample that's higher. Al came down a bit this run while fe went up 1 ppm w/a hair more miles. Like already mentioned the silicone is higher and is appropriately flagged. Pretty low mileage on this Civic.

 

[OneLonelyBurrito]

Check the intake tubing. Around that era (and maybe others), it's pretty common for the rubber to split from pushing and bending it in order to open up the air cleaner box. It can be small enough to suck in debris but not big enough to trigger a check engine code.

Yep, and that intake tube is kinda annoying to replace.

Just took a look at the intake boot, it is definitely ripped. Looks like I will be replacing it when I get a chance.

 

[Hall]

Just took a look at the intake boot, it is definitely ripped. Looks like I will be replacing it when I get a chance.

Consolation is the OEM parts are pretty inexpensive.

Yep, and that intake tube is kinda annoying to replace.

Come on, you're even a pro ! Honestly, I don't recall it being that bad. I also had to replace the EVAP component that's under the cowl. It wasn't bad at all, just the bad part was having to lean/bend over to reach both parts.

 

[The Critic]

Come on, you're even a pro ! Honestly, I don't recall it being that bad. I also had to replace the EVAP component that's under the cowl. It wasn't bad at all, just the bad part was having to lean/bend over to reach both parts.

I just remember it being more annoying/difficult than it looks.

 

[OneLonelyBurrito]

I just remember it being more annoying/difficult than it looks.

It definitely is more annoying/difficult then it should be. I just finished replacing it, while not exactly difficult, I have taken plenty of intake hoses off before and this was definitely the most difficult. Between the limited access to everything and very tight fitting intake hose, it took much longer then I thought it should.

 

[cptbarkey]

It definitely is more annoying/difficult then it should be. I just finished replacing it, while not exactly difficult, I have taken plenty of intake hoses off before and this was definitely the most difficult. Between the limited access to everything and very tight fitting intake hose, it took much longer then I thought it should.

Good job, next UOA if you choose to do Si will trend down and possibly the wear metals too.

 

[OneLonelyBurrito]

Good job, next UOA if you choose to do Si will trend down and possibly the wear metals too.

It will be interesting to see that for sure. I’m also wondering if the air leak was messing with fuel trims causing some of the fuel dilution.

I also immediately noticed the car was driving better after changing the hose. So the air leak was definitely messing with it.