Automotive

Honda direct injection engine carbon buildup?

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  • Mar 13th, 2019 4:58 pm
Deal Expert
Aug 22, 2011
30339 posts
16185 upvotes
Ottawa
MoxGoat wrote: can of seafoam in the gas tank when it's half full. Buy either seafoam spray or any generic throttle body cleaner, take off the air intake and spray into the throttle body towards the valve. Activate the valve to get behind it as well. put down some papertowel or some cloths to catch any cleaner that comes out of the throttle body. After reattaching everything idle for a bit and go for a good drive (give it some gas to get any left-over carbon to come off the throttle body)
No, because it won't run down the backside of the valves.
You need to spray directly into the intake manifold.
Deal Guru
User avatar
Feb 11, 2007
12974 posts
13109 upvotes
Oakville
booblehead wrote: https://www.canadiantire.ca/en/pdp/0380162.html

on sale this week at Crappy Tire
Waste of money to put that in your tank as it won't clean your intake side.

OP, CRC cleaner seems to be pretty popular for intake cleaning. Ideally you should be spraying it at every extended oil change. Letting it soak in should also help if it's bad. A cheap $10 boroscope can help you see how bad it is.
https://www.canadiantire.ca/en/pdp/crc- ... 8077p.html
Jr. Member
Aug 29, 2012
117 posts
97 upvotes
WINNIPEG
This is what I am planning on doing.

1. Use top tier fuel. I try to stay away from ethanol but kind of hard when you don't out premium fuel into the car. I believe Petro, Esso, and Shell are the places I will be buying gas from.

2. API SN and SN plus. Manual calls for SN however I think I will shoot for oils that have the SN plus rating only.

I also am considering using pure class 4 synthetic oil. I used to run Amsoil in my S2000. Was not cheap, I'll have to do more research as to my other alternatives.

3. Make sure intake filter is cleaned on changed on a regular basis.

4. Premature replacement of spark plugs. Don't need any excuse to have incomplete combustion.
Deal Guru
Aug 14, 2007
10234 posts
1516 upvotes
Toronto
jackrabbit000 wrote: This is the least of your worries. Read up about Honda engines and oil dilution.
Read up about the recalls that were done.

Now that said, I had the recall done on mine and am happy that warranty was extended for the parts affected as this shouldn't have been an issue to this magnitude in the first place.
Deal Addict
Aug 28, 2014
2038 posts
437 upvotes
Toronto, ON
woof wrote: Only fill up with a Tier 1 gas.

But let me ask you this one question:
Where are all these posts from Honda owners complaining about horrible carbon build up on their DI engines?
^Perfect example of answer with zero research or knowledge of topic. Carbon build up is from EGR and crank case ventilation. Magic pixie gas isn't going to do anything because it doesn't even come in contact with the intake on a GDI engine.

At least this can be mitigated by maintenance, my greater concern with current generation of cars is the CVT belts exploding. These things are made of 400 individual metal plates held together by bandsaw blades to turn a pulley into a pushey. It doesn't matter how well you make them, fatigue endurance limits be damned; you're continuously flexing a metal belt around at thousands of RPM, failure is not a matter of if but when. And when it does it will send those hundreds of metal plates flying around everywhere rendering the transmission unsalvageable.

https://www.civicx.com/threads/cvt-belt ... les.33596/

I thought these manufacturers had made a great leap forward when they ditched the timing belts that were guaranteed to fail for chains that would last the life of the engine and now they took a step back to belts that fail somewhere else.

And on the diluting engine oil matter:
https://www.civicx.com/attachments/4d8b ... eg.138483/
Deal Fanatic
User avatar
Sep 12, 2007
6101 posts
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Greely
vkizzle wrote: All you can do is mitigate the issue.
Walnut blasting is the only sure way to get rid of the deposits.
This. Or soda blasting. I just had mine done this summer (Audi). Generally not cheap either.
Deal Addict
Oct 6, 2015
2411 posts
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corcoran_chris wrote: Hello, I assume like most direct injection engines Honda will face the same issues of carbon buildup on valves due to fuel not acting like a solvent and washing carbon like traditional engines.

Is there a way to mitigate this at all ? I rather service this regularly to maintain fuel efficiency and hefty maintenance down the line.
Use the proper spec oil, which is 0W-20 synthetic. And don't change it more often than the manufacturer advises per the maintenance minder. Not changing the oil more frequently than spec is crucial.

Stay away from additives. The only thing they're good for is lightening your wallet. Spending extra on fuel is also a waste of money, use the octane recommended and no more.


Most of the problem arises from misinformed, but well meaning people who change their oil way too often, or who use the wrong oil (which is often the case with a scammy dealer or scammy quickie lube oil change). "More" is not "better".
Deal Fanatic
Mar 21, 2002
6253 posts
921 upvotes
nabiul wrote: At least this can be mitigated by maintenance, my greater concern with current generation of cars is the CVT belts exploding. These things are made of 400 individual metal plates held together by bandsaw blades to turn a pulley into a pushey. It doesn't matter how well you make them, fatigue endurance limits be damned; you're continuously flexing a metal belt around at thousands of RPM, failure is not a matter of if but when. And when it does it will send those hundreds of metal plates flying around everywhere rendering the transmission unsalvageable.

I thought these manufacturers had made a great leap forward when they ditched the timing belts that were guaranteed to fail for chains that would last the life of the engine and now they took a step back to belts that fail somewhere else.

https://www.civicx.com/threads/cvt-belt ... les.33596/
Baloney. You give one single example of a Honda CVT failure and that's a salvage vehicle which was put on the road again and then suffered CVT failure. The discussion you point to includes comments from others that we don't know what the maintenance of this car by the previous owner was like and in any event the concussion of the accident could have damaged the transmission and led to eventual failure. The point being that a salvage car should never be used as an example of anything. It soils your credibility. Was that all that you could come up with to show how horrible Honda CVTs are????

And yes, I will acknowledge that there may be CVT problems from other manufacturers, especially on earlier generation CVTs.
nabiul wrote: And on the diluting engine oil matter:
https://www.civicx.com/attachments/4d8b ... eg.138483/
On the oil dilution matter you seem to be trying to blame that on the CVT? You selectively failed to point out that the problem only occurs on Turbo equipped DI engines (either CVT or manual). Non Turbo DI engines do not have a problem.

I own a Honda Fit DI CVT. There are no problems with the CVT on the Fit and there are negligible problems with carbon build up on the valves although these cars have only been on the road since 2015 so higher mileage may prove this wrong. The Fit does not have a problem with oil dilution because unlike the Civic it does not have a turbo.
Deal Fanatic
Mar 21, 2002
6253 posts
921 upvotes
nabiul wrote: ^Perfect example of answer with zero research or knowledge of topic. Carbon build up is from EGR and crank case ventilation. Magic pixie gas isn't going to do anything because it doesn't even come in contact with the intake on a GDI engine.
Quite right, but the benefits of top tier gas is the additives, not because they clean the valves which they don't on a DI engine, but because they clean other parts of the engine preventing carbon build up on things like the spark plugs which promotes more complete burning. Top tier gas is recommended by most car manufacturers and is specifically mentioned in their manuals so I guess they've done the research and are satisfied with what they found.
Deal Fanatic
Mar 21, 2002
6253 posts
921 upvotes
burnt69 wrote: Use the proper spec oil, which is 0W-20 synthetic. And don't change it more often than the manufacturer advises per the maintenance minder. Not changing the oil more frequently than spec is crucial.

Most of the problem arises from misinformed, but well meaning people who change their oil way too often, or who use the wrong oil (which is often the case with a scammy dealer or scammy quickie lube oil change). "More" is not "better".
Huh? First time I've heard this nonsense. Please give your reasons for this advice.
Deal Addict
Mar 16, 2015
1599 posts
262 upvotes
Still Honda engines kicks ass.
My accord's 2.4 liter engine burns oil but very good at 170K kms and over 15 years of use.
Just top up the engine. I use good oil though.
you need to drive some long drives to burn the carbon and what not... Doing short trips in Canada Winters is cause of many problems.. get the baby to heat up
Newbie
Mar 31, 2009
59 posts
57 upvotes
burnt69 wrote: Use the proper spec oil, which is 0W-20 synthetic. And don't change it more often than the manufacturer advises per the maintenance minder. Not changing the oil more frequently than spec is crucial.

Stay away from additives. The only thing they're good for is lightening your wallet. Spending extra on fuel is also a waste of money, use the octane recommended and no more.


Most of the problem arises from misinformed, but well meaning people who change their oil way too often, or who use the wrong oil (which is often the case with a scammy dealer or scammy quickie lube oil change). "More" is not "better".
Can you elaborate how a fresh oil, assuming of course the correct spec for the car, can damage your engine even if done "more frequently" then the Manufacturer interval ?
I am not referring here for the first oil change on a new car that may have special spec oil meant for the first few hundred kms but to regular oil changes.
This is hilarious.
Deal Expert
Aug 22, 2011
30339 posts
16185 upvotes
Ottawa
CocoJambo wrote: Still Honda engines kicks ass.
My accord's 2.4 liter engine burns oil but very good at 170K kms and over 15 years of use.
Just top up the engine. I use good oil though.
you need to drive some long drives to burn the carbon and what not... Doing short trips in Canada Winters is cause of many problems.. get the baby to heat up
B16 and B18 are the best engines ever produced by Honda!
Deal Addict
Oct 6, 2015
2411 posts
1311 upvotes
woof wrote: Huh? First time I've heard this nonsense. Please give your reasons for this advice.
Its not nonsense.

The reason is that brand new virgin motor oil contains the most volatile components that boil off. And used motor oil, as it has been subjected to many hours of distillation due to being in service in a hot engine, contains substantially less.

The test that approximates this in the lab is known as the NOACK volatility test. Basically it heats oil up for a while, and measures how much is lost to evaporation.

Its these distillates that go through the PCV and crankcase breathers, that ultimately end up contaminating the intakes. So yes, the best thing to do to largely eliminate the problem is to minimize the engine's exposure to brand new virgin motor oil.
zlicht wrote: ...
See above. Its not hilarious at all.

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