What Causes the Hemi "Tick?"

Discussion in 'Dodge Challenger General Discussions' started by SRT-Tom, Feb 19, 2012.

  1. SRT-Tom

    SRT-Tom Well-Known Member Staff Member Super Moderator Article Writer

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    Many of us have heard a ticking sound coming from our engines.

    In a previous SRT Engineers Chat session, it was explained as follows:

    "You will not hear the valve seating at or near idle conditions unless you have seriously aerated the oil system and hence the lifters. You will also not hear the moly wearing off the piston skirts. A piston that is too small in a bore too big will result in a cold slap that can be heard at cold (I mean cold like -20 deg F) idle. We do a lot of testing and guage pistons and bores very carefully to make sure you as our customer cannot detect the piston movement in the bores - hot or cold. I expect what you hear is the injectors which do make a clicking noise that can be heard and gets slightly noisier as the injector temp is elevated. The noise is caused by the injector pintel as it opens and closes and while we have not been able to eliminate the noise due to the required operation (you need the fuel) we have done some work with minimizing the noise with isolation."
     
  2. SRTSammy

    SRTSammy Full Access Member

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    The Viper V-10 in the SRT-10 Ram made the same noise. I was told the same thing, it's the injectors.

    Good info! Thanks Tom
     
  3. heminit

    heminit Full Access Member

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    Good to know, thanx for posting.
     
  4. SRT-Tom

    SRT-Tom Well-Known Member Staff Member Super Moderator Article Writer

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    Here's more information about the Hemi tick.

    After hard driving it is normal to get a pronounced tick that goes away after a while. The reason is that the high rpm squeezes oil out of the lifters and you get a little slack in it. That's the tick. After some easy driving or sitting, the lifter pumps back up and is quiet again. This is normal on a Hemi.