So the piston moves farther at higher rpm?

 

In his mind it must.

No one ever advocated constant redlining of the car, that is abuse. I said it should be a regular occurrence.

 

I've only redline my fit once since i got it. 10k miles now, we will see if mine last.

 

Found this for the '11 , page 19 in the Technology Reference Guide provided with the car . I'd think you'd get the same guide for '15 and '16 . This should apply even greater for the D.I. and carbon deposits from what I've read . VALERO and CITGO are Top Tier . Go to Top Tier Gas for retailers and details . Click photos to enlarge .

 

I remember when I was stationed in Bermuda back in the 1970's, The Navy ran what is now the Bermuda International Airport, as a Naval Air Station. Because the speed limit on the entire island was 25mph, they let us take our cars out on the runway and blow them out once a month, due to the carbon buildup driving so slow all the time caused. I don't think those cars were DI.

My question is how can you have carbon buildup by redlining an engine? That seems to be the exact opposite of the problem we had, back in the day.

It sounds more like bad gas.

 

Vanguard , this was a topic on GOSS' GARAGE about a month ago . Talks of using a catch can . Says not to high rev . This is also being discussed here , 6,650 Mile Oil Catch Can Results. - MirageForum.com .

 

Pictures of catch can installed in a 2014 Mirage .

 

It looks like Lexus says "open her up" for carbon build up.

@ minute 2:40


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So, I was in the market to replace my 2009 Fit with a 2016/17 Fit, I don't like the GDI carbon issues. I use to build race/street motors when younger and don't have issues on doing it. But you know what, I don't want to do it, I don't want to pay someone to do it, nor should you have too. Crap design that should never have seen the light of day in this industry. "They" all jumped on board with this crap design before seeing the ramifications of this design, or even worse yet, they knew about this problem and kept it quiet.

To me , this GDI fuel delivery system design is an "Epic Fail". What engineer would want his name on a design that the motor has a very high chance of getting clogged up with carbon at 60,000 to the point of having to pull the head or intake manifold and cleaning the carbon off. Now we are getting manufactures adding small cleaning injectors in front of the intake valve for a total of 8 injectors because they are having big time issues.

If they can get it to work GREAT, if not "shipp can" the GDI injection system as a whole and go back to an injection system that works for 200,000 miles with no issues other then worn out parts from years and years of use.

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Yes, slightly, due to stretching of the connecting rod and the inertia effects of the mass of the piston.

However, and this is a big however, is the fact that this only applies to engines that have a lot of wear and have developed a ridge at the top of the cylinder. By this point they are already on their last legs. I've never had a feelable ridge on a modern engine with under 200K on it.

So, how did this bit of "shadetree wisdom" come about? My theory is that teen gearheads bought clapped-out cars and then drove them as teens will do. Suddenly Grandma's Tercel that hadn't seen over 3K in 220K miles was being revved to 6K+. Something had to let go and it might as well be the piston and rings.

C'mon, can't you recognize an excuse dreamed up by the brass to give the men a recreational opportunity?

Frankly, I think that "carbon buildup" is being overblown. Since it is so universally "known" a lot of top-end issues will now be blamed on it even if they have nothing to do with it. Since customers seldom see the actual parts it is easy to tell them something that they want to hear.

Catch can for blowby? It would take a heck of a lot of oil blown by to create significant buildup on the intake valves. Enough that oil consumption would be really high. Certainly not a situation you see with a new engine!

 

A theoretical possibility with a clapped out shitbox isn't a factor in a tiny Honda with 10k miles, or a result of any break-in technique. OP's getting snowed because the local shop doesn't know why.


Happens all the time if you have good leadership. A long time ago my Guard unit's training NCO had to fit some "individual movement techniques" time into the annual training calendar. I don't think Battalion realized that what they approved was a day trip to a paintball place.

 

A few points I'd like to chime in with, as this has been one of my struggles in 8+ years of BMW ownership as well.

-With DI engines, the gas doesn't actually spray on the back of the intake valves. This lack of spray lets gunky carbon buildup amass. As mentioned this is a problem inherent in all DI engines, and tends to be even worse with turbo engines.

-Products like SEAFOAM can help clean carbon deposits in the engine, but simply adding a can of seafoam to your gas tank WON'T WORK in a direct injection engine for the reason stated above.

-So, if you want to use seafoam on your DI car, you need to introduce it to your engine through one of the vacuum lines leading to your air intake tract. You can do this by either pouring a can of seafoam into a cup and VERY slowly suctioning a bit up along with some air, then letting just air get in, and repeating; or you can do it by slowly spraying the aerosolized version of seafoam straight into the line.


-Do this with your engine running, and the throttle being lightly applied (a thousand or two RPM above idle, if you hear the engine start stalling, stop the seafoam and let it breathe for a bit). While this is happening, you should be seeing pretty thick whitish smoke coming from your exhaust.

-I do this before every oil change on the BMW. Ideally, this should be done shortly before changing the oil, but still giving some time to drive the car for a little while before the change. Ideally, before you take the car in for service at Honda. I haven't yet done this on the Fit because I didn't think the carbon buildup was a problem on these cars, and because of that IDK which vacuum line to use. Sorry.

-A way to "one shot" clean the carbon buildup is via "walnut shell blasting." This was not a well known procedure prior to about a decade ago after Audi and BMW began introducing turbo DI engines and those engines began accumulating miles. At this point, plenty of Euro tuner shops should be familiar with this. It's what it sounds like. You take the manifold off and expose the internals, and literally "sandblast" the engine except with pieces of walnut shells, which scrapes away at the deposits.

-You could technically scrape the deposits off yourself by hand. Take off the manifold, soak everything in seafoam for a few hours / overnight, and use a scraper of some sort. However, for the shops, walnut shells are faster, easier, and likely more fun, though it requires special equipment.

-It cost me $550 for my BMW @ about 55K miles. I had started doing the seafoam at 25K miles with every oil change, and was told that my intake valves were still gunked up, but nowhere near as bad as most others have been.

-Another product I use is an Oil Catch Can on my BMW, which catches any oil blow-by. It's about the size of a small can of soda (like those 8 oz cans, not the regular 12 oz), and each oil change I do have a small amount (maybe a couple mm worth) of oil to empty out of it. I installed mine after my walnut blasting, so I don't know if overall it has helped with the rate of carbon buildup, despite catching a small amount of oil pretty consistently. I don't know of any such product for the Honda Fit.

-I don't think the problem is as bad for Honda as it is for BMW/Audi, but there have definitely been blown Audi S and RS engines due to the problem. So I'm sure as our Fits get up in miles, we will probably start noticing symptoms, however likely not having bad symptoms at 30K miles which is not unheard of on the German DI turbo engines. A complete engine failure at 10K miles like OPs, however, is extremely rare and unusual in any case.

-Here's the buildup on a BMW 135i:



-Here's a link to an info page for a well known BMW shop:
Walnut Shell Intake Valve Cleaning for BMW


That's just my 0.02, hope it's useful for someone.

 

I don't believe this carbon build up is 100% the problem of EGR valve gasses and junk coming back through. NOPE, that is not all of the problem here.

It would be 100% solved by venting it into the catch can and venting it into the air, that some have done. Some of this and I think most of this is because of valve overlap back feed. The problem gets wasted away no matter what is causing it with injectors before the valves.

We need to get this problem figured out by the manufactures and really the only way to do it is have a % of gas being injected in front of the valve. Like 80% GDI and 20% legacy injected. At least for starters.


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Trust me, there were already plenty of "recreational opportunities" in Bermuda!

The cars (and small motorcycles), did run better after an afternoon of "take-off and landing" (which is what we called it).

 

I really don't feel like the car is running up to par ever since the head was replaced. It feels sluggish down low and I'm not confident that i-vtec is working. I'm not sure that taking it to the dealer would be worth my time, but I would like to know if i-vtec is working...

Anybody else had any issues similar to mine?

 

Have any of you hooked up a catch can to your GK?

 

I never said red-lining is bad or good, I simply said breaking an engine in as it is to be used is a good idea..

Porsche used to run-in their engines well above redline for an extended period of time before installing them in the 911.. It was the only way to get proper break in so they could warrantee a high strung engine. Nikasil cylinder lining technology eventually fixed the problem for them, only a few hundred million in R&D to do it.

The wear on a fresh cast iron or steel leave engine cylinder wall often occurs in the first 10K or so miles of the engines life, the upper ring ridge (If your engine develops one not all blocks do) WILL break rings, seen it multiple times.. Ford 460's that are in motorhomes are notorious for it, same with the 454 chevy V8's. And the ring ridge is not always obvious, it can be less than a ten thousandth of an inch and do damage.

Oh and you can measure the stretch of the pistons at higher revs with the right equipment. Been there done that.. You use a ultrasonic probe and it gets imbedded in the head.. We used it for small ford twin cam formula engines at a shop I worked at. Mechanical injected engines on methanol running 14:1 or more compression. Your space between the piston and head gets very very tiny..

If you deal with race engines a lot you'll see most blown engines blow when you lift off the gas, if you ease down off redline your way less likely to prang the motor.

Just my experience take it or leave it as you like..

 

Advisor's remarks are contradictory. Bullshit. A new cylinder head comes with new valves, so if they replace the cylinder head, there is no need to clean any valves.

His remarks about gasoling are also bullshit. You should use Top Tier gasoline most of the time, regular grade. With top tier regular and premium they will both have the same additive package. With most non-top tier gasoline they also have the same additive package for regular as for premium. There is no need for premium. Premium is only to prevent knocking in high compression engines. While the Fit is high compression, it has a knock sensor that prevents knocking. This is there for the purpose of preventing the need for premium. Good oil and good fuel has all the additives you will ever need. Everything this advisor says seems like bullshit.

Driving the car hard will reduce carbon buildup in the injectors and combustion chambers.

I don't think it is impossible that the dealer did not actually put in a new cylinder head but rather simply billed Honda for that. You said the car was running fine. It was running fine and the steering light and tire pressure light came on? These have nothing to do with the engine. Probably nothing was wrong with steering or tires – or the engine either. Something was making lights come on that has nothing to do with the things the light are supposed to tell you. Same thing may be true about the P code. An ECM code? That's the main computer. Reloading the operating system or updating it may be what was needed to correct the light and stop the P codes. Or replacing it.

 

I wouldn't stand for that.
If they are keeping my vehicle and ordering parts for it, then they better know what is wrong, and you have a right to know as well.

Telling you AFTER they have kept your vehicle and ordered parts?

I wouldn't be happy with that dealership.
If they knew enough to order parts? Then they knew enough to tell you what was wrong.

 

Makes no sense. Simply driving the car faster is not necessarily going to result in engines rotating faster, for a onger time, and blowing out the carbon. To do that all you need to do is run the car at the same 25 mph, but in a lower gear (higher engine to wheel gear ratio). Even old-fashioned planetary automatics allow you to do that - you simply put the shift liver in Low or Extra Low, instead of Drive, and drive around like that for 20 minutes or more.