General Honda Direct Injection Petrol Engines

Discussion in 'General Discussion' started by tomwillie, Thursday 10th Dec, 2015.

  1. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    As petrol engines in new Jazz, HR-V, Civic Type-R and future Honda petrol engines are likely to be direct injection I sent an email dated 13/09/2015 to Richard Clissold, Customer Relations Technical Advisor, Honda UK, asking:

    “What measures are taken by Honda to prevent coking up of inlet valves due to crankcase fumes now having to be burnt off in the engine?
    I understand that Toyota have introduced secondary port fuel injection on their direct injection engines so that oil fumes deposits are washed off the inlet valves.”

    I never had a reply so have asked the service manager of my local Honda dealer, Norton Way at Letchworth, if he can find out.

    To minimise the problem of inlet valve coking up some advise using top grade petrol & fuel additives but if fuel in direct injection engines does not pass inlet valves this will be futile but will probably extend life of the direct injection injectors. Others suggest adding catch cans, but these will only delay the problem.

    I would not touch a direct injection petrol engine unless it had dual port fuel injection as some Toyota & Audi/VW engines now have. Even then expensive high pressure injectors are likely to be less reliable than lower cost lower pressure port injectors.

    Ask An Engineer: GDI Problems In A Nutshell - The Truth About Cars may have to stop script running to see this article as many comments follow it.
     
    Last edited: Thursday 10th Dec, 2015
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  2. SpeedyGee Administrator Staff Team

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    It's not new technology though as it already been used for many years in diesel engines.
     
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  3. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    We know that many modern diesel & petrol engines have problems with direct injection injectors together with many other problems associated with modern diesels. I also expect the higher pressure fuel pumps required by direct injection petrol engines will be much more expensive to replace. At the moment best to hang onto current port petrol injection engines for as long as you can.

    Bosch claim up to 15% reduction in fuel consumption others only 3% from use of direct petrol injection over port injection. However, if its a head off job to remove coke from a direct injection cylinder head & inlet valves every 30k to 50k miles the petrol savings will all but be lost, but CO2 will have been reduced.

    I believe it is safe to say that a Honda port injected petrol engine is likely to be much more reliable than a Honda direct injection diesel engine.

    If I hear back about what steps Honda take to prevent coking of inlet valves on direct petrol injection engines I'll report back.
     
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  4. Ichiban Founder Staff Team

    England CJ Leeds
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    Tom you love TSB,recalls and manufacture cock ups. We had this conversation in the past we need to lose this conspiracy theory Honda are duping their customers it's not in their ethos mate. I would put my life savings and my Honda shares into this what your read on the Internet and in yank land is never reality. So if I were you open your mind you love Honda's I do more than Helen ( don't tell her that ) but they will never ever betray you .
     
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  5. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    @Ichiban I am just interested in facts & made this post in case yourself or @Beefy might be able to provide answers. Toyota and VW/Audi have both come up with the solution of dual port injection but what are Honda doing to prevent coking up of inlet valves in their direct injection petrol engines new to UK market?

    An obvious solution would appear to be to lightly pressurise the crankcase & vent to the atmosphere, as used to happen, but through a filter that traps any pollutants then no nasty fumes from crankcase go past the inlet valves. This filter would need cleaning or replacement at services.

    Linked to this question is who makes the direct injection injectors for Honda's direct injection petrol & diesel engines as Bosch have had many reported direct injection problems in German cars?
     
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  6. SpeedyGee Administrator Staff Team

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    They are usually Kiehen injectors.
     
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  7. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    Thanks, they are Japanese which is reassuring, been in business since 1956 & it appears have worldwide manufacturing facilities.
     
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  8. SpeedyGee Administrator Staff Team

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    I think they are also a subsidiary of :gohonda:
     
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  9. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    This is reply from Honda UK regarding Honda direct injection engines & if any measures taken to prevent coking up of inlet valves:

    Dealer emailed that Honda have advised regarding your query below,
    “What measures are taken by Honda to prevent coking up of inlet valves due to crankcase fumes now having to be burnt off in the engine?
    I understand that Toyota have introduced secondary port fuel injection on their direct injection engines so that oil fumes deposits are washed off the inlet valves.”

    "Oil maintenance is the most important thing here. Using the recommended oil and regular oil changes help with the ash build up in the oil which eventually coats the valves etc and causes problems later on in life
    Honda have advised that there is no information available about any specific design changes with the engine regarding this."

    I consider this reply most unsatisfactory & would not consider buying a Honda direct injection petrol engine car unless I knew how coking of inlet valves is prevented.
    At the moment the favourite to replace my 2.4EXi Accord is the new Lexus IS 200T that has dual port fuel petrol injection engine as does the petrol engine in the Lexus 300H hybrid version.
     
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  10. Ichiban Founder Staff Team

    England CJ Leeds
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    This issue has not surfaced here as HR-V petrol is the only direct injection petrol engine sold in the UK. No point crying on milk which has not spilt.
     
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  11. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    The new Jazz & Civic Type-R petrol engines are also direct injection.
    Furthermore the next Civic due in 2017 is most likely to have turbo direct injection petrol engines in the range.
    Both Toyota & VW/Audi for starters are now using dual port fuel injection to overcome the problem of coking of inlet valves on their 1.8/2.0 litre direct injection petrol engines.
    If Honda cannot state how they intend to overcome the coking problem then I'd rather not take a chance. Just using the correct grade of oil & regular oil changes will not solve the problem that will inevitably occur with single direct injection as Honda UK appear to believe.
     
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  12. Ichiban Founder Staff Team

    England CJ Leeds
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    Yeah forgot about the others two..:Whistle: but where have you heard from where Honda direct engine have this coking issue in Europe, we are covering the same issue of the past . i am not interested in the others manufacturers or Honda in the US, where is the proof for here.?
     
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  13. tomwillie Valued Contributor ★ ★ ★ ☆ ☆

    England Tom Royston
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    I made this post should a member in Europe where 9th Generation Accords are sold with DI petrol engines be able to give feedback. However, it usually takes two/three years before problems show up.
    Within this link: COKING IN DIRECT INJECTION ENGINES? - FerrariChat.com
    Someone posted that:
    "Toyota has the right idea with an injector to "wash" the valves.
    Some suggest Seafoam, but that sounds like a mess, smokey and who knows what it does to the cats and exhaust.
    I like Honda's vapor liquid separator built into the block.
    This is still a problem for non new Honda and Toyotas without their fixes.
    I guess Gumout would foul the cats too. "

    If Honda are incorporating the equivalent of an internal catch can within their DI petrol engines to prevent carbon build up on inlet valves then why not just conform if true.
    The answer to my question is supposed to have come from Honda UK Technical Department & I am not impressed by it.