Typically my 07 gx is garage stored, but the last two nights it was outside where temps dipped into 30s. In morning when starting there was a very audible slap/knocking noise (not a ticking exhaust manifold noise). It was most audible in the cab, and I couldn't really hear it when walking around engine. Anyone have any ideas as to what it could be? I don't remember my 06 v8 4runner ever making a noise like this. Once warmed up, noise is gone and engine runs great ( also runs great while making knocking noise).
Piston slap/knock?
- Thread starter Jminz
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are you sure it's coming from the engine? seems odd you'd be able to hear it better in the cab than with the hood up if it was. could it be something vibrating underneath the cab? did you try seeing if it increased with throttle? did the noise happen both mornings?
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- #3
Great questions and I wish I would have paid better attention and gotten under car when it was happening. I am back home now and it is garaged so I barely heard it when I started it today.
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- #5
100%? Why are you so sure? There is no ticking noise. I'm pretty confident its not. I would be able to hear that pretty well outside vehicle, no? It's a knock or slap, not a tick. I'd prob rather it be the manifold rather than a piston slap.
You would hear a piston slap outside of the cabin more than inside. Have you done any maintenance recently?
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- #7
Oil change
Front, center and rear diff oil
Valve covers
Trans pan dropped and filter serviced
All done in the last 3 weeks
did it make the noise before the maintenance? is the tranny full after the service? My guess would be the tranny, not the motor. I am not a mechanic and still learning these trucks.
My GX has the exhaust manifold leak that sounds very much like my old GM LS motor's cold start piston slap. It sound absolutely horrible for a minute or two, though it runs just fine, and then once warm it quiets down to a very light tick that is nearly indistinguishable from belt noise.
With all that said, I hear all of this far more outside of the vehicle than inside.
Tom
With all that said, I hear all of this far more outside of the vehicle than inside.
Tom
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- #10
No. But it has also not seen temps in the 30s during a cold start in my ownership since it's always garaged.
