Carbon Buildup on FIT Earthdream Engine Valves @ 52K--Input?
 

I would like to get some advice/input regarding the attached photo of the butterfly valve on my 2015 FIT with 52K miles and know if anyone else with a 2015+ FIT has had this problem?

This photo was taken by the dealer's service advisor in the normal course of regular maintenance last week that has been done at the dealer since day 1. This FIT has only used Chevron fuel and Mobil 1 synthetic oil changes on schedule and air filter changes as needed.

He said that they are noticing carbon buildup on Honda Engines on various makes including FIT and Accord, some with substantial buildup on units that are only 1 or 2 years only and with less than 25K miles. He said that when they present the photos to new vehicle owners, they are not happy that the cost to remedy this is not covered by Warranty but the dealership does not know what else to do. They are documenting their findings for their records and Honda he says. He said that dealerships Toyota end has also inspected the valves on various models and has not seen this issue at all with their engines, just the Hondas.

The service advisor recommended cleaning the throttle body, fuel injectors, and de-carbonize the engine at a cost of 100’s of dollars.

I have not noticed a performance issue with my FIT and the service advisor says that performing the above work will not improve the engine performance at all--it will just keep the carbon from spreading which will require more extensive cleaning and engine warning light coming on in the future. No other benefit to cleaning the valves he says.

I would appreciate some input on:

1. Has anyone else here confronted this Carbon buildup on their 2015+ FIT (EarthDream Engine)?

2. What have you done about it?

Thank you all in advance for your time.

Photo of 2015 Honda FIT Engine Valve at 52K miles.

https://cimg7.ibsrv.net/gimg/www.fit...cf175e32c0.jpg

The dealer replaced a leaky valve cover gasket on my 2001 BMW 330i that I had bought new. The service manager mentioned that was the cleanest valves he had ever seen in a car with 110K miles. He associated that with my changing the oil/filter every 5K miles with Mobil 1. Yea, that was excessive at the time when the oil minder usually takes 15K miles before a recommended change. Also, the car was driven mostly on the highways. Are your driving mostly city miles, and are you changing the oil/filter regularly?

Mobil 1 every oil change since new when the maintenance minder says to change it--approximately every 7000-7500 miles on my car.
I drive mainly busy city stop and go, with occasional long highway trips.

I'm a bit confused by the Dealer's determination that it's carbon buildup because this is the throttle body and no crankcase gases pass through it. The throttle body sees only clean air as having passed through your engine air filter. What I see in the photo is a typical butterfly valve on a 50K Mile vehicle and it's nothing to worry with. I'd just leave it be.

The good news is that if you wish to clean it some day, the job is easily worked with a spray can of Throttle Body Cleaner available at any auto parts store. Don't use brake cleaner or something else that "might work", as some throttle bodies are Teflon-lined and the wrong spray will strip away the coating and assure more rapid buildup of crud in the future. Also, resist moving the butterfly valve with your fingers as you spray, as with some vehicles this action will freak out the TB Position Sensor and a reset procedure will be required. Better to have the engine running with a friend at the wheel to goose the gas pedal to keep the engine running and sucking in air as you spray. Be sure that the "straw" on the spray can is firmly in place.

Winter is over and the heavy summer driving season has yet to begin. In this dull in between season the service departments are scratching for work to keep their people busy. Some scaremongering over carbon buildup should help stampede customers into pulling out their wallets and paying for some useless work to be done. I suppose they could have chosen the rust on the exhaust pipes thing and the horror of being gassed to death by carbon monoxide but perhaps the service departments are saving that one for next year.

This quote from your post says it all. You simply don't have a problem at the present time. There's been a lot of chatter about carbon buildup on DI engines. Strangely enough though, cases of an actual carbon problem affecting performance on Fits seem to be rarer than unicorns. The GK engines getting older, getting more miles on them hasn't changed anything - still more unicorns around than gunked up Fits.

Save your money until the day when you actually have a real problem with your Fit.

I think it depends how long you plan to keep your Fit, and of course just how "many" hundreds of dollars we're talking about.

It could be worth several hundred dollars to do the cleaning every 30k miles or so, if you hope to keep the car until it hits 100k. If it's more disposable - I mean, it's not really extreme to sell a car at 50k people do that all the time - then perhaps you don't care.

It doesn't look like you have any kind of super bad case btw. Not at the throttle. I would kind of shrug and go, OK I could clean this now or in 20k miles it doesn't look like a "has to be done today" thing. But if I had access to it today .. I would clean it so I can stop thinking about it.

Sounds at least like your dealer is playing straight with you. Including pictures, saying they're documenting it, comparing with Toyota engines (I assume they also have a Toyota dealer).

If it helps - all the techs are going to be doing is - spraying and wiping the throttle body, running the engine while spraying it in to clean the manifold (this is the "decarbonizing the engine), and adding a tank of fuel injector cleaner. They are not taking the engine apart beyond where they've got. There is no need if it runs fine IMO. The cleaner will also add octane which will temporarily make your car feel faster (maybe) and get you going "wow they were right it does feel better".

Curious, what regular maintenance was being performed at 52K that necessitated a peek inside the valves?

Sounds like they went looking for a problem and found one. We've told the manufacturer about this problem, but they don't seem to care, so we're offering this special service just for you. It'll cost a lot and won't improve performance at all, but it might help someday. Yeah, where do I sign up?

I wouldn't worry about it.

The photo shows dirt build up. Which is normal. Just use a Carb or Throttle body cleaner and spray.

is there not a crank case hose/breather pipe .... that goes to the intake, past the filter but pre throttle body?



(per the T REV thread)
https://cimg5.ibsrv.net/gimg/www.fit...dd2a2e56d1.jpg

https://cimg1.ibsrv.net/gimg/www.fit...9178fa0d31.jpg

Breather pipe.
There is a check valve located at the valve cover side. The check valve allows filtered air to flow into the valve cover but not the other way. So your throttle butterfly should not be oily

No it goes post throttle body if you're talking about from the PCV right?

no, not pcv. jingjang does correctly illustrate the item in question, the pipe that connects crank case to the intake. per his green circle, that pipe sits after maf, but before tb



more info about that check valve please

Thank you to everyone that posted responses here—such a knowledgeable group of folks on this forum—very impressive. This discussion may help to determine what may be causing the valve condition in the photo I posted.

This morning I had the opportunity to discuss this matter with a representative of Honda. We were on the phone for more than 30 minutes some of the time with another representative coming on the line to ask questions. While it won’t help to determine the cause yet. I wanted to share with the group here what Honda’s preliminary position is:

They were able to see all the service records for my vehicle the Honda representative said as it was all performed at the Honda Dealer except this last one that had not been transmitted yet. I guess they have access to this data?

This is what I told Honda on the phone:

I am aggrieved that the Dealership told me this week that I need to spend $350 to clean the throttle body, fuel injectors, and de-carbonize the engine at 52K miles and this will need to be done regularly. The service advisor said this must all be done in order to prevent the valves from sticking, failure of the injectors, the engine warning light from coming on, and a more extensive and expensive cleaning of the engine later on. While they were not immediately able to see the valve photo I posted here for everyone on Fitfreak during my conversation--I described it to them. I told Honda that the Dealership told me that build up of Carbon is something they were alerted to on Honda’s FIT, HRV, and Accord Engines built since 2015. The service advisor told me that they were first alerted to this issue on Accords that were only 1-2 years old that had Engine Warning lights coming on attributable to excessive carbon on the valves. That they have seen this carbon build up on 2018 Accords. It was this that caused the Dealership to become proactive and examine more engines recently.

I told Honda that the Dealership told me that this service is not covered by Honda’s warranty (Honda engine warranty is 60K miles) and that the advisor said that when they present the cost of de-carbonizing the engine to new car owners—some that only had the car for a year or two—all are upset.

Because my conversation with Honda was so long I am going to just outline their responses for clarity without any commentary from me:

1. Honda sells cars to dealerships but does not own any dealerships or repair facilities.
2. Honda publishes a manual that new car dealers are required to give to new car owners that specifies the exact maintenance that must be done on the vehicle.
3. Honda also equips all 2015+ model FITS with a maintenance minder that also alerts the owner when to perform maintenance and what maintenance to perform.
4. Cleaning the throttle body, fuel injectors, and de-carbonizing the engine is Not anywhere in Honda’s manual or part of the maintenance minder for a Honda FIT at anytime in the life of vehicle.
5. There is no recall or technical service bulletin on the 2015 Honda FIT engine or engine components at this time.
6. Failure to perform the engine service recommended by the dealership will Not void Honda’s engine warranty as it is not a required maintenance service at any time.
7. Performing the engine service recommended by the dealership could void the Warranty if it was not performed properly so Honda does not recommend doing this type of service.
8. Honda does not understand why the dealership is recommending this engine service if there is no documented mechanical or performance issue with the vehicle.
9. If I want to contact the Dealership service manager when she returns and the Dealership wants to document for Honda a mechanical or performance issue effecting the engine that de-carbonization can fix, Honda would be willing to willing to pay for the service under the Warranty.
10. The HondaCare warranty on my 2015 FIT (8 years/120K miles) may also cover this de-carbonization service as they will be responsible for the engine after the 60K Honda warranty expires, but the dealership will still need to document specifics why this service is required now.
11. They will submit this case to Honda’s engine engineering department for review.
12. If they feel this is an issue affecting the fleet, then there may be a recall or technical service bulletin issued to dealers in the future.

---

>>I will meet with the service manager when she returns to the dealership in July. Can someone here help me in how to explain to her how this may be caused by a mechanical issue with the engine, the engine design, or engine associated parts like the injectors or emissions hoses that are causing the condition you saw in my Valve Photo so that she could submit this as a Warranty claim to Honda?

Um, question....warranty claim for what? If your Fit isn't suffering any performance deficits, exactly what are you claiming? You're well out of warranty at 52K, so what is at stake here?

Honestly, if the dealership hadn't gotten picture-happy, would this even be an issue?

If you play devil's advocate here - about all that's getting done at this point is that your throttle body buildup, whatever it is, is documented. I'd sit on any problems until they arise, then you can go back to Honda and the dealership.

What photo of the valve? That's a TB picture.

There is no issue and the dealer is just trying to sell you unnecessary stuff IMO. Just tell them no thanks and move on. The car is not having any issues.

Part number 7
https://cimg7.ibsrv.net/gimg/www.fit...189c63ac1d.pnghttps://cimg0.ibsrv.net/gimg/www.fit...f918efaad1.jpg

Fujisawa: "I think it depends how long you plan to keep your Fit, and of course just how "many" hundreds of dollars we're talking about."

I love this FIT and was planning on keeping it forever (or until the engine blows). I have spent a lot of $$ customizing it with a solid 2 inch completely hidden under the bumper cover with just the receiver peaking out, a full time video recording system (important if you live in Los Angeles), and some other electronics. It's a great car I have taken on road trips from LA to Portland, LA to Vegas, Arizona with incredible performance at great speeds and cargo capacity.

I always said at the office--if I won a powerball or mega, I would probably buy a second car, but never get rid of the FIT.

They wanted $350 to do the work.

Exactly Bargainguy. That is what concerns me so much.

When I went for service that morning I expected a Mobil 1 Synthetic Oil Change as I usually get, and since I still have not replaced the brakes at 52K, maybe it was time to do the fronts, and maybe a brake fluid exchange at the same time. At the last maintenance they told me that I was 3 mms and have time for brakes.

So last week the service advisor said the fronts are at 2 mms and left it up to me whether I want to replace the brakes now, or wait another 7K to the next maintenance. He said they checked all the drive belt, fluids, and hoses and filters and everything is okay but that I should probably replace the cabin air filter on my own soon.

But he then said:"Before you commit to spending money on brakes today, there is something more pressing that you should take care of on your car that we have been seeing on other FITS, HRV, and Accords--some as early as in the 1st or 2nd year of ownership."

He goes on to say that it was sensors on Accord Engines that have been triggering Engine warning lights and they have found that it was attributable to carbon buildup due to these types of engines. So they examined other Honda engines from 2014 to 2018 and found the same situation.

I really did not understand what this man was talking about and how this is already an issue on my 52K mile FIT. I did not have this problem on my 2009 FIT.

I told him, listen, just lets do the brakes and the brake exchange today because I know it will need soon and I have time to hang out today.

Like a doctor who discovered a cancerous tumor on your forehead that needs to come off, he took the tone of listen, you really need to have this work done on your fuel system before it infects the entire engine and costs you a lot more $$$...I am telling what we are seeing on these Earthdreams engines.

I just told him again, do the brakes, I will think about the carbon removal for $350.00 another time.

Then about 2 hours later, he calls me in his office, says brakes are done, and says that while they under the hood doing the brake fluid exchange, he instructed the tech to take a photo what he described at the butterfly valve and send it to his phone so he can show me because he feels I was not believing what he is telling me about these engines. He showed it to me, and I said send it my phone so I can study this. So he did that while I was standing there. That is the photo I posted here.

If I did not have such a strong relationship with this service advisor since 2009 on my other FIT, and service manager for the past 2 years, I would have blown this off.

But this man is telling me that this is problem that needs to be dealt with.

So I raised the issue on this forum to get additional information and input?

Bargainguy: Honda's Engine Warranty is 60K miles and this FIT has an extended Honda Warranty on the Engine (and other parts) (Hondacare) to 120K (8 Years).

It was Honda that brought up that because I have 2 overlapping warranties that I can address this with the Service Manager to see if there is something going on with this Engine that would trigger a warranty claim.

I was looking for input on how I would present this to her? as some of the Other members here apparently have great technical knowledge about this car and engine.

I'd tell her as follows:

"I spoke with Honda customer service, and none of their documentation shows any issues with this engine nor a requirement this service be done. They offered to review the need for the procedure if you write them and explain its necessity. Otherwise, I'm following their advice and saying no."

Sounds like the MOC Fuel Optimization Service my dealership recommended. Like yours, it's nowhere in the manual. At least they didn't do a hard sell, and were asking $100 or so. Look it up on YouTube.

I'd look for a different Honda dealer.

Also, I hope to keep my Fit forever, too!

[QUOTE=exl500;1430372

Sounds like the MOC Fuel Optimization Service my dealership recommended. Like yours, it's nowhere in the manual. At least they didn't do a hard sell, and were asking $100 or so. Look it up on YouTube.[/QUOTE]

Thank you very much for your advice exl500.

I think you are right on it with those videos--that is what they want to do probably.
I watched a couple of the vids for the MOC Optimization and then there was a video from this garage that happens to be near me that uses BG engine cleaner.

I'll tell you--if the service advisor showed me the pic and asked for 100 to clean it like at your place, I probably would have gone with it. But when someone asks for $350.00 for something I don't understand completely and I'm not have a problem--that will cause me to investigate.

Did you do the de-carb on your FIT yet for 100?

It's a wear and tear observation. Nothing unexpected. Normal engine condition after 52K miles. I would discount the dealer's recommendations. Keep driving and spend your time changing oil/filter regularly.

I did, and my mileage improved a little. It does feel a bit proper too.

^peppier^

did you do a cold air intake or ever change the air filter? that throttle body looks filthy.

The dealership is ripping you off.

1. That photo is not of an engine valve. It's the throttle body.
2. $350 to clean your throttle body is a ripoff. You can buy a can of throttle body cleaner for less than 1/10th that and it'll last you the life of the car.

That's normal, I'm surprised you are rather worried over it. And it's NOT engine valve, that's a photo of the butterfly valve of the throttle body!! I have a 2016 Honda Fit, and a 2007 Accord V6. The Accord has over 304000 miles as of this morning. I clean that throttle body every 25k miles, from the back side also by taking it off the intake manifold. It's nothing out of normal, nothing a $3 bottle of carb cleaner can't fix. Find a new dealer and a service advisor that knows cars.

OP knows that is a throttle, he just keeps calling it a valve for some reason. Probably because a throttle IS technically a type of valve. In the original post he specifically calls it a butterfly valve which is not wrong. But it's confusing everyone, including, I suspect, Honda 😊

The engine air filter has been replaced by me a few times already whenever it looks dirty--usually every other oil change so @ approximately every 15K miles. I am on my 4th or 5th filter since new.

Are you saying that the reason the TB is dirty as shown in the picture is caused by a dirty air filter?

I don't know what a cold air intake is? The car is serviced on the maintenance minder service schedule by the Honda Dealer. I don't personally do any service on the car except to change the bulbs and cabin and engine air filters. The Honda dealer has not told me that a cold air intake was done or needed on the FIT--I have never heard of the term before.

The service advisor at the dealer called it a Butterfly Valve so I adopted his description and sometimes shortened it to "valve" relying on what he hold me. When he described the work that needed to be done for $350.00--he said that I need to clean that "valve" before it starts sticking.

I only now know it to be a TB because posters here call it a TB.

I wish I could do this work myself.

I need to find someone in the Orange County California area that can do it inexpensively since the majority of posters here say the same thing about getting a spray can for a few dollars. One other poster in Florida said he went to his dealer and they took care of it for $100.00

Your photo shows normal dirt build up over time. You just need a can of throttle body cleaner and spray/clean it yourself. No need to pay the exhorbitant amount quoted by the dealer.

What's stopping you?

Cleaning a throttle body, even when it's mounted on the intake manifold, takes just 15 minutes max. You just need to keep the valve open with your left left while you spray carb cleaner on a paper towel and stick it in with a set of needle nose pliers and start wiping. You get carbon build-up even if you are on OEM intake, it's not an OEM or aftermarket cold air intake issue. I've done this cleaning on multiple Honda's with OEM intake air filter, still gets carbon build-up. It is NORMAL. You are burning fossil fuel with oxygen, there are by-products produced and passing by the throttle body.

Trd I think you may be over simplifying things .. Yes the throttle is very easy to clean but getting access to it took me at least 45 minutes (ge) ... Unlike me some people aren't interested in getting into hands on work

That is fine. If you don't want to get dirty, then you pay someone else to get dirty. But in America, labor rate is very high. If you'd like to pay then do so and knowing that you'll pay a premium for simple services. I choose to work on my own cars because I got tired of people breaking my cars in different shops and suggesting things I don't need. Because car work is a lucrative business where cons are run on a regular basis. So I invested in my own tools to almost never go back to any shops for anything. In this age of youtube videos and online forums, that's how I learned everything, to the point that I started servicing people's cars on the side and I do IT for a living. it is your choice. Get scared by car shops telling you what you need or learn yourself and finding out how most simple items are easy to work on yourself with simple tools.

45 minutes?! On the GK5, it should take less than 5 minutes. Remove the fixed breather line (attached with a spring clamp) and use an 8mm socket to loosen the clamp holding the intake on the throttle body.

If you wanted, you could also disconnect the MAF harness but that might not be totally necessary.

isn't carbon build up major problem for turbo / supercharged engines?

for small I4 engine like FIT, it wouldn't build up to the point that it would become trouble?

I would need to find a safe location to drive the car to do it and let it cool down as I live in the middle of a highly congested city with busy street parking only. On the street you risk someone backing into you parallel parking while you are under the hood. I usually change the air filter and check filters in a shopping center parking lot after shopping but that does not take long before security bothers you.
Don't have tools--not sure what to buy to do the job.
Don't know where it is under the hood or what to uncover or unbolt to find it.
Not sure what formula to buy to clean it right.

I think if I worked with someone once or twice on a FIT, I could do it, but starting from scratch I am not sure of?

Those are all very good reasons :)