Questions for the K20C1 engine experts here.

[Clark_Kent]

1. There isn't proof out there about a trend of carbon build up problems in Honda DI engines.

2. The easiest way to avoid problems with a warranty claim is to not install aftermarket parts like a catch can. If that worries you, don't bother during the warranty period.

3. 1st engine change?
Here is your answer from a valid source.


4. 250K miles on these engine?
There isn't enough data out there to know that yet.
The K20C engine came out on FK2 CTR (europe), not enough years in the road to know their longterm reliability but so far the engine seems to be pretty good.

How is a rando tech at a dealership a valid source?! There's only one answer that's "valid" and it's in the owner's manual. Follow the maintenance guidance laid out in the owner's manual, full stop. I don't see how this still remains an open question.

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[TypeRD]

@pigfacedalarm Well that’s the thing. Define “a lot.” We need actual data. Of course those with problems will post the most info, right? But how many are out there with zero problems? I think that number is surely MUCH higher.

 

[NoelPR]

Catch cans are a big thing among the VW crowd, with their DI causing so much valve gunking over the years. I've heard nurmerous Mazda and Honda people say that carbon buildup is not an issue with their cars, because the motors are designed to prevent this, but they can never point to the specific engineering that prevents the issue.

If Honda has managed to prevent carbon buildup on the intake valves with their DI-only motors, I'd love to know how they're doing it. So far, I haven't found any solid explanation, which leads me to believe that it's likely a myth.

I don't know.

Dude, earthdream engines had been out for over a decade. At this point you should see hundreds of posts in every honda community board talking about their bad experience with carbon build up issues.

I had not seen a trend out there in the internet.

 

[NoelPR]

How is a rando tech at a dealership a valid source There's only one answer that's "valid" and it's in the owner's manual. Follow the maintenance guidance laid out in the owner's manual, full stop. I don't see how this still remains an open question.

So the honda tech with years of training and experience is just a random guy and is considered irrelevant. Specially when that same person said "follow the MM", the same recommendation found in the owner's manual.

I see ....

Ignorance to the maximum expression.

 

[TypeRD]

Valid point! Those with issues are the most vocal, but it seems like not a lot of people even inspect their valves because they have this assumption that Honda’s don’t have this problem. So the problems could be there but not enough are tearing down to inspect. Kind of a quagmire!
if I ever get to 20k miles, I plan on walnut blasting. Won’t hurt and I’ll know how everything looks. But I’m not even at 2k yet so don’t bump this reply in a year

It definitely doesn’t hurt to inspect them periodically. I want to say that valve checks/adjustments, at least for the Type R, are supposed to be done in regular intervals (more often than non-Type-R’s). I want to say it’s every 30k miles, but I can’t remember where I saw that. So if folks aren’t keeping up with this detail…well…that could be the source of the problem! I think this info may even be in the owner’s manual itself!

 

[VLJ]

What’s interesting is that there’s virtually no info about any widespread issues with Honda’s DI engines. They’ve been making DI engines for what…over 10 years now? Surely we would see gunk reports stemming from cars that are this old and well over 100k miles, but there are none. This tells me that comparing Honda’s DI engines with others is not a valid comparison. I’m certain you’ve read as many things as I have from armchair engineers claiming that all DI engines are faulty inherently. I think both Honda and Toyota have proven these “experts” wrong by now. Guess they figured out a smarter way to build an engine. Imagine that!

Toyota deals with the DI issue by not having DI-only engines, other than the BMW motors in the Supras, and the new three-cylinder turbo in the GR Corolla, which is supposedly co-engineered with Yamaha. Otherwise, all their other cars feature Toyota’s D-4S port/direct injection system.

 

[TypeRD]

Toyota deals with the DI issue by not having DI-only engines, other than the BMW motors in the Supras, and the new three-cylinder turbo in the GR Corolla, which is supposedly co-engineered with Yamaha. Otherwise, all their other cars feature Toyota’s D-4S port/direct injection system.

That’s right! I completely forgot about Toyota’s hybrid port/direct system.

Here check this out. This appears to be the “parent” of the current K20 turbo. It explains some interesting things about Honda’s DI system and valve timing. Might be something here that helps explain why we aren’t seeing major carbon buildup issues in the DI K20. It appears that they time the valves so that they get misted with fuel.

 

[optronix]

Looking for answers to problems that don't exist, in a place with no formal validity?

 

[TypeRD]

Looking for answers to problems that don't exist, in a place with no formal validity?

Welp…guess we should shut down this whole forum because no one here is an engineer for Honda, which means no info here is “formally” valid let alone helpful.

 

[Gansan]

Additional data point on not doing the first oil change too early:

http://www.urvi.net/forumfiles/SN/A060800.PDF

See page 4 where Honda says:

What’s really important to remember here is this:
Don’t change the factory-fill engine oil because it
looks dark; just make sure it’s at the right fluid
level. To ensure proper engine break-in, the
factory-fill engine oil needs to remain in the
engine until the first scheduled maintenance
interval

 

[CTRifecta]

Regarding carbon build up, Toyota def has an advantage over Honda with their D4S system (port + DI) however it's pretty amazing that Honda has managed to keep carbon build up issues from being more widespread.

I also do think that at this point, DI technology is 15+ yrs old now in cars, so perhaps it's just not as big of a deal anymore. Also, engine oils have probably adapted as well, with formulations that leave less deposits (someone correct me here though).

 

[TypeRD]

@CTRifecta Yes, I think better oil tech and better fuel additives have both helped reduce the rate of carbon build up.

 

[VLJ]

Additional data point on not doing the first oil change too early:

http://www.urvi.net/forumfiles/SN/A060800.PDF

See page 4 where Honda says:

That's from all the way back in 2006.

 

[Gansan]

That's from all the way back in 2006.

True, but oils and engine fundamentals haven’t really changed that much. FK8 owners had this same discussion in civicx.com and the Honda dealers 5 years ago said the same thing—don’t bother changing the first time until the oil life is down to 20%-15%.

I used to change my oil every 3000-5000 miles but other than making me feel good about my super clean internals, I don’t think it makes much difference as long as you aren’t late in changing it.

 

[optronix]

Welp…guess we should shut down this whole forum because no one here is an engineer for Honda, which means no info here is “formally” valid let alone helpful.

For questions like this, yes. Might as well shut it all down. Burn it to purge the evil lies too.

Seriously this whole conversation is about hearsay. I'm not sure why there's an expectation that some imaginary "experts" exist that somehow know the science of this specific engine better than Honda engineers, literally on a molecular level, and can give you the "real deal" better than what's in the actual owner's manual?

Just has a whole lizard people vibe to me, sorry.

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