Excessive oil dilution after TSB fix

[thebook92]

2017 Si coupe, 54k miles, owned since 50k. Dealer did an oil change when I bought it, and according to the Honda service record the TSB for the oil dilution has already been done. After 4,000 miles of mostly highway trips lasting multiple hours, my oil level has steadily increased to the point where it's a solid half quart overfull (dipstick level shown after checking twice with a cold engine on level ground). Right now my plan is to either shorten my OCI's or run a higher viscosity oil so I have a higher safety margin, so if I have to live with this I will. That said, is there anything else that can be done about it? Will Honda even care about it, if the TSB has already been performed?

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[DKL]

I've done several UOAs, and fuel dilution is definitely worse in colder temps (I'm in Maine). The dilution "fix" didn't really help. I run 0w30 year round, and change every 5k between November and April. Also. Don't let it idle excessively. Fuel dilution is negligible in the summer, for me.

 

[elmer255]

My ‘18 Hatch Sport didn’t even warm up on the few cold days we had here in NY last week - dealer had it for 5 days and replaced thermostat - today it’s 18 degrees and yesterday was cold too and so far so good - A/C fix and software did nothing for me

 

[Design]

If you're really concerned about it, run a UOA and check wear metal rates or for unusually low viscosity. Cold readings will always read higher vs. readings taken after 3-5 minutes following shutdown. Condensation can also play a factor regarding overnight readings.

It's been explained to me that the 1.5T can operate up to 2.5 CM above the fill line without issue. And in extreme cases, the MM intervenes as early as sub-3K.

CN: To me it doesn't seem concerning.

 

[DKL]

My fuel dilution was getting up over 4% last winter, but wear metals were comparable to the previous summer, FWIW.

 

[swankyjake]

I got the TSB fix done last January. After 6 months, 6,500 miles, I did an oil change this last weekend. Ended up with close to 4.25 quarts. Filled a gallon, plus had an extra 1/4 quart I put in another container. The smell of gasoline was so bad, getting worried that this still isn't fixed.

 

[elmer255]

I’m really torn on weather or not to return mine when the lease is up - I like the car and the mechanic in me says this dilution problem seriously reduces the lifespan of the engine - especially with the turbo - but most tests show wear metals normal - my gut says it has to affect durability and reliability down the road

 

[Design]

I got the TSB fix done last January. After 6 months, 6,500 miles, I did an oil change this last weekend. Ended up with close to 4.25 quarts. Filled a gallon, plus had an extra 1/4 quart I put in another container. The smell of gasoline was so bad, getting worried that this still isn't fixed.

If you're honestly concerned, run a UOA and report back. Despite the dilution, my hunch is that your wear metals and viscosity will check out fine.

The snow is a tell-tale sign regarding what is driving your excess fuel.

 

[thebook92]

Going to do a UOA once I hit 5,000 miles on this oil. That said, I picked up a P219D code, that the dealer said was a bad injector. I kind of doubt it, but I do wonder if that isn't part of the issue.

 

[Gruber]

If you're really concerned about it, run a UOA and check wear metal rates or for unusually low viscosity. Cold readings will always read higher vs. readings taken after 3-5 minutes following shutdown. Condensation can also play a factor regarding overnight readings.

Why would cold readings always read higher?

 

[Design]

Why would cold readings always read higher?

I suspect it's due to a small amount of oil draining back from the valvetrain, turbo, inlet, return line, etc. It amounts to around a 1-2 MM delta in both my Mazda's 2.3 L3VDT and the 1.5T - both TCDI.

 

[Design]

Going to do a UOA once I hit 5,000 miles on this oil. That said, I picked up a P219D code, that the dealer said was a bad injector. I kind of doubt it, but I do wonder if that isn't part of the issue.

We've been finding injector failures are popping up a little more often than we'd like. A leaking injector could result in additional fuel making contact with the oil film along the cylinder walls, which in turn may get scraped back down to the sump.

 

[Gruber]

I suspect it's due to a small amount of oil draining back from the valvetrain, turbo, inlet, return line, etc. It amounts to around a 1-2 MM delta in both my Mazda's 2.3 L3VDT and the 1.5T - both TCDI.

Yes, but the thermal expansion of oil is significant and it works in the opposite direction. For example the volume of hot oil could be over 5% greater than the volume of cold oil. I found no noticeable difference between hot oil measurement several minutes after shut off and the next day check in the garage (~50 F). It seems that at these conditions the temperature effect and the draining effect cancel each other for me. Unless it's really just 3 minutes, which I haven't tried.

 

[thebook92]

I replaced the injectors last weekend (not as bad of a job as I was fearing) and changed the oil at the same time. It did fix the cylinder imbalance code, thankfully. Oil analysis report attached for y'all's perusal. Curious to see how much (if any) replacing the injectors helps.

 

[Design]

That actually looks like a good report when comparing to the universal averages (despite the fuel presence).

What was the oil life % at, according to the MM?

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