Knock/Pop Noise under acceleration

[craigaward]

When I put my foot down I can hear a knocking noise (only one knock) which sounds like a pop coming from underneath the engine bay. I have also noticed a buzz around the gear linkage area in 1st and 2nd esp when cold. Im assuming that the knock is causing the buzz. Any ideas? I think it could be a mount esp with it only being one knock. Cheers in advance

 

[craigaward]

Is this likely to be the dogbone mount?

 

[Hutchie]

i would reccomend checking all engine mounts. prob dogbone

 

[craigaward]

Right... so i have changed the dogbone and the noise is still there. I am concerned about the buzz/vibration from first to second when clutch is dropped - could this be another mount/shield?

 

[craigaward]

Any ideas?

 

[TimR26]

Check the metal bracket under the battery, mine was snapped were it attached to the chasis and caused a metallic sounding noise.

 

[craigaward]

Cheers atouba ill go have a proper look when the rain stops! I must admit the 172 has been very disappointing in three months of ownership - broken alternator, broken water pump, new aux belt, 2 x tyres, new windscreen, steering wheel (plus squib issues) lambda sensor. One more thing and ill lose faith completely!

 

[Christopher]

Gearbox mount. Not the dogbone.

 

[craigaward]

The noise is defo coming from under battery area

 

[craigaward]

Is the gearbox mount a big and expensive job?

 

[Christopher]

If you need all the parts that make up the mount, it's £140 in parts. That said, most of the time it's just the metal spindle that the box braces itself on. It shears off and you get movement.

Easy to fit though.

 

[Christopher]

If it's just the spindle, let me know because I have a spare.

Take the battery out and look for damage on the metal mount underneath.

 

[craigaward]

Will have a look in the morning as it's getting dark now. I hate winter!

 

[craigaward]

Had a look at the mount which looked pretty new and all seemed well. There was a bolt underneath which was a bit loose so I have tightened it and will see tomo on the way to work. I'm thinking it could now be an exhaust mount as the centre section is brand new and I suspect it was put on in a hurry

 

[craigaward]

The rattle can be heard from under the passenger side wheel arch and between the engine and batter (general gearbox area) when on idle and through 1st to 2nd. Is this likely to be linked to my mount problem or something more sinister?

 

[craigaward]

Right had the car looked at by a garage. It looks like the clutch release bearing is the slight ticking noise. They said the knock wasnt an engine or gearbox mount after checking them all and decided it was the backbox mount. I have changed the mount and the knock remains. It only happens when either pulling away or when accelerating when in first. Any other ideas?