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JUST GOT MY TERRAINE AWEEK AGO 2.4 4CLY.WONDER IF ANY ELTS HAS A TAPPING NOISE FROM ENGINE.
 

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Might it be the direct injection you are hearing ?
 

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It's very noticeable on my V-6. Sounds like a helicopter flying above! They seem to have very noisy lifters, only heard at idle. Almost would think it has a diesel engine..... ;)
 

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I've heard this sound on every Terrain I've seen in person, it's the fuel injectors. It is very noticeable at idle, but nothing to be concerned about.
 

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There has been a tapping sound emanating from under the hood of our Terrain since day one.
We are not concerned about it at this point in time.
I'll take the covers off and have a listen with a screwdriver or something to see if I can pinpoint it come summertime.
 

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Do OHC engines even have lifters?

I believe it has something to do with the direct injection injectors. They spray directly into the cylinder and must operate at very high pressures.
 

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SnowItch said:
Is the screwdriver for your hearing aid <g>
But of course!
My "Stethoscope".
;)
 

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Just bought a 2.4 L Terrain, I have the tapping noise too. Went to the dealer to check it out. There is a bulletin on this. It is caused by the fuel pump (located on the rear of the cylinder head). It is under very high pressure due to the direct injection, thus causing the sound. My car's sound is much louder than most. I checked out other 2.4 Terrain's and 2.4 Equinox's and those were not as loud. I have contacted and placed a case number with GMC on this. It's been a few days , still no word from GMC.
 

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It may be a good idea to check it with a meter. I know the sales person at a Chev dlr yesterday could tell the difference. He wanted me to trade for one of his right then. I could barley hear the 2.4 Equinox. I'll wait to see if they respond any. May end up trading.
 

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Does anyone know if this Tapping sound occurs on a Terrain 6 cylinder??
 

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Maybe I'll shoot a video/audio clip with the hood up and upload it this weekend so you can hear for yourselves.
I used to hear a tapping noise when we first got the vehicle.
Maybe it's still there and I'm not paying attention or have unconsciously blocked it out?
:-\
 

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SnowItch said:
It's truly amazing what the human mind can block out. Once you do the research and convince yourself that something isn't a problem, poof, you won't hear it anymore.

It will be interesting to hear it if you can pick it up. But even if you do, there are so many variables (inside, outside, the microphone, clear day, cloudy day, open field, trees all around) that can affect the acoustics that it won't really provide an accurate comparison.[/color]

My old next door neighbor had all sorts of audio equipment that he would be able to set up some type of measuring device and tell me if my engine had changed its noise over time (he used to engine tracking the week by week progress of an engine breaking in).

Another case were it would be interesting to pick the brains of one of the engineers and see what level of knocking was considered "acceptable"
I will do it tomorrow morning.
We're about ready for dinner, then it's movie time for ma and pa and the kids are going out (woo hoo!)
 

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SnowItch said:
I have never heard it. I have been told, that it does occur (a natural result of the Direct Injection), but because the engine/valves/cylinders are different sizes, the resulting "tapping" is at a different amplitude/tone/volume so that it is not noticeable.

Having said that, and having a sister who has perfect pitch, my guess is that she would hear it (she hears lots of things no one else can).
I can hear our V6 tapping away happily when it's idling. Only when I'm outside of the vehicle though, I can't hear it from the inside.
 

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I noticed the tapping noise on my V6 the first time I used my remote starter and was very concerned untill I found out that it was caused by the high pressure levels of the direct injection and not by problimatic valves like I first thought.
I only notice it at idle and only from outside the vehicle, I've never noticed it from inside the cabin.
 

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GMCdriver said:
I noticed the tapping noise on my V6 the first time I used my remote starter and was very concerned untill I found out that it was caused by the high pressure levels of the direct injection and not by problimatic valves like I first thought.
I only notice it at idle and only from outside the vehicle, I've never noticed it from inside the cabin.
My thoughts and experience exactly.
 

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Been driving my Summit White V6 for more than two weeks and do not hear an engine tapping noise. The car seems very quiet to me.
 

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Took the car back in (2nd visit) at the request of the service manager. He had called the region rep which ask him to check the noise out. My tapping is more pronounced than most. I have compared the car to other Terrains and Chev Nox with mine having a louder sound. So far all I get as per bulletin's that this is normal and that's that. If I wanted a car which souned like a diesel, I would have looked for one.

I assume my options are:
1. Keep going up the ladder
2. Trade the car in on one without all the noise ( found a Nox that you can not hear)
3. Live with it (not option for wife)
4. Buy something else vs a GM car. That would be a shame for I have owned 13 GM cars.

Maybe it will work out just like Toyota. They said for 2 yrs they didn't have an issue.

Note: calls to GMC customer service have not been returned after the initial call. Maybe they all got laid off.

As they sell these cars, there may be more of us with the same issue and they will find a way to fix it.
 

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Just so you know you aren't crazy, I can hear the loud "tapping"... almost diesel like(from the sound clip)
 

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Roesterman said:
Just so you know you aren't crazy[/color], I can hear the loud "tapping"... almost diesel like(from the sound clip)
No worries there, Roesterman, but thanks just the same!
;D
I pay the shrink big bucks to keep reminding me as well!

Thanks for taking the time to download, listen & feedback!
 
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