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flexdog1's avatar
flexdog1
Explorer
May 30, 2013

Cummins Frieghtliner M2 Business Class Engine Noise

I have a brand new 2013 Jayco Seneca with 360 miles on it. Engine is a Cummins ISB6.7. When I drive it, or rev it up, it sounds like it is sucking a lot of air through a screen - it is a very loud air noise coming from the engine compartment up in front of the passenger seat.

I am thinking this will go away once it breaks in, but I wonder what the noise is? It sounds like the turbo charger or something that is pulling alot of air through the big filter on that side. When at idle, you can't hear it.

Any ideas? This is the first big diesel I have owned.
Thanks,
flexdog1
Class C
  • carringb's avatar
    carringb
    Explorer
    May 30, 2013
    I would peek under the hood and make sure all the coupler hoses in the intake (from the airbox to the turbo) are intact. If one of them was left off, it makes that sound, and means you are not pulling air through the air cleaner. The hoses are secured with hose clamps, and there's a good chance some of the stuff under the hood was removed during the RV build, and sometimes things get missed during the re-install. The 6.7L normally does not make much intake noise, and the fan should only engage during idling and hard pulls on hot days.
  • flexdog1's avatar
    flexdog1
    Explorer
    May 30, 2013
    Nevadanick, thank you for the reply, but I don't think it is the fan. I had a loaner over spring break and I heard it kick on a couple times and what I am hearing is not the same thing. Plus, this noise starts from the first time you start the engine, not once the engine gets hot enough to engage the auxiliary fan.

    I will check the hoses.
  • huntnjim's avatar
    huntnjim
    Explorer
    May 30, 2013
    I have a 2013 Seneca same engine.
    when the temperature gets around 200 the clutch fan comes on to cool the radiator and is very loud. so loud it is hard to have a conversation inside the cab. This is a great unit other than the noise. I believe it is common.
  • ecoast's avatar
    ecoast
    Explorer
    May 30, 2013
    nevadanick wrote:
    Radiator fan


    x2

    it's your fan clutch...
  • az99's avatar
    az99
    Explorer
    May 31, 2013
    Go to the Jayco Owners forum. There are several pages of discussion about the engine noise.
  • flexdog1's avatar
    flexdog1
    Explorer
    Jun 02, 2013
    I FOUND IT!

    The large silver hose that runs up to the radiator area had a loose clamp back at the engine. As I am still learning this engine, I am not exactly sure what this hose is, but after tightening the clamp back and the engine, the sound went away.



  • carringb's avatar
    carringb
    Explorer
    Jun 02, 2013
    That's your "charge air cooler" line aka intercooler line. It cools the hot air from the turbo before it goes back into the engine.
  • ronfisherman's avatar
    ronfisherman
    Moderator
    Jun 02, 2013
    carringb wrote:
    That's your "charge air cooler" line aka intercooler line. It cools the hot air from the turbo before it goes back into the engine.

    You may want to check rest of the clamps on both sides of the engine.

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