Clunking Noise on Acceleration and Deceleration

[sjwarden914]

Hoping someone might know what this noise is, or at least have some good ideas. I am worried that it is the transmission.

I am not that sensitive to squeaks and rattles in a car, but this noise have me worried.

So here is what happens:

This car has a lot of torque and when lets say in 2nd or 3rd gear I am coasting at 3-4K RPM, and then I hit the gas with anything more than 1/6th throttle the car will start to jump forward and accelerate hard. That is good, it should do this. The problem is along with that torque and acceleration I get a click/clunk sound. The harder I hit the throttle the more noticeable the sound.

The sound seems to be coming from just under the gear shift and slightly toward the passenger front seat, or passenger front corner. However depending on how the car is moving and what road surface I am driving over the sound does seem to move around a little and sometimes even seems to be coming from the passenger side rear.

This sound also occurs when first getting going in 1st gear from a stop, but it is usually less noticeable and if I make a particularly smooth start it does not happen at all.

In the higher gears 5th and 6th I do not ever get the sound, probably because much less torque and power, car is not being pushed forward as quickly in those gears. In 4th I have experienced the sound on occasion, not as frequent as 2nd and 3rd gear.

I have also noticed the same sound when getting on the throttle in 2nd or 3rd gear, and getting up to lets say 4Kish RPM, and then abruptly getting off the throttle, no pedal braking just engine braking.

Otherwise the car is perfect, power is good, clutch is great, no fault codes. The car does not make this noise under any other conditions. The car is stock other than a K&N filter.

Thanks for any help, hoping this is not a big issue. I have an appointment with the dealer on the 15th, and it might be useful to provide them with any of the thoughts members of this forum have.

 

[Intuit]

May be able to devise a way of checking whether the rear engine mount is maxing out... perhaps with squish/paint marks.

The other thing that can max-out, though this generally *NOT* a complaint under those conditions, is the dual mass flywheel.

 

[kivnul]

Maybe check the passenger side engine mount bolt? If you keep the throttle steady and rock the car violently left & right does it make a sound as well? (this would help rule out exhaust and steering related noises)

 

[sjwarden914]

Thanks for all the help and props to kivnul for calling the passenger side motor mount. The problem is solved.

I opened the hood to check the passenger side motor mount. Put my hands on the engine and pushed and with very little effort the entire engine pushed back. Turns out the bolt where the motor mount attaches to the passenger side of the car was completely loose. This is the bolt that is directly underneath the coolant reserve. I was able to get a wrench in from behind and tighten up. Test drove the car and everything is perfect, noise is gone.

Hope this helps someone else with the same noises down the road, this was a really simple fix. Will be canceling the trip to the dealer.

 

[Intuit]

Is there some particular reason that this mount bolt would come loose?
Wonder what the torque specifications are? (I'll look it up later.)

 

[Liono]

Had my FiST for the past year and the transmission always clunked when I was shifting even with my TS RMM. I just noticed recently that it’s making the same noise you described in the same actions. Just checked my passenger mount and everything seems fine. I’m clueless as to what it is. Ugh!


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