Drop the plastic cover and inspect your exhaust hangers. Grab the exhaust pipe in different area's and rigorously move/shake it. It sounds to me based on the videos that something is rubbing the exhaust parts on the chassis. That is only a guess!
Rattle from beneath dash when starting
Hi all, recently posted regarding my 2014 BM Mazda 3 SP25GT Manual.
I'll summarise the issues:
-On start up and turn off of the engine, there is ALWAYS a rattle that is heard only from the cabin, and it sounds as though it's under the dash.
-applying load to the engine, stop start, acceleration, idling then reving to 2k then dropping back to idle, etc, any movement at low rpm where stronger amounts of torque are applied sets off the rattle.
-car is jerky to drive, change gear, accelerate in low gears (more than I would expect the car to operate)
What I've done:
-replaved transmission mount, and inspected other mounts which appear to be in good condition.
-gotten another person to wedge the mounts, this sometimes stops the rattle but also causes a lot worse vibration and cabin noise.
If you listen carefully, you can hear the knocking rattle when I start or turn off the car in the linked video (1), and in (2) you can hear the rattle under low rpm revving.
(1)
(2)
I'll summarise the issues:
-On start up and turn off of the engine, there is ALWAYS a rattle that is heard only from the cabin, and it sounds as though it's under the dash.
-applying load to the engine, stop start, acceleration, idling then reving to 2k then dropping back to idle, etc, any movement at low rpm where stronger amounts of torque are applied sets off the rattle.
-car is jerky to drive, change gear, accelerate in low gears (more than I would expect the car to operate)
What I've done:
-replaved transmission mount, and inspected other mounts which appear to be in good condition.
-gotten another person to wedge the mounts, this sometimes stops the rattle but also causes a lot worse vibration and cabin noise.
If you listen carefully, you can hear the knocking rattle when I start or turn off the car in the linked video (1), and in (2) you can hear the rattle under low rpm revving.
(1)
1 - 14 of 14 Posts
Thanks for the response mate. I threw the car up on ramps and inspected the mounts. They were all fine, they have some play but no more than what I would expect. If you grabbed the exhaust pipe and gave it a good shake it would rattle back and forth. I sprayed some lubricant incase it was squeaking and wedged the mounts to see if that changed the rattle - it did but I am in the process of moving into uni and will likely get a mechanic to inspect further.Drop the plastic cover and inspect your exhaust hangers. Grab the exhaust pipe in different area's and rigorously move/shake it. It sounds to me based on the videos that something is rubbing the exhaust parts on the chassis. That is only a guess!
Hi, did you figure it out? I’m having the same issue
Glad to know I'm not the only one. Unfortunately not, I did find that messing around with the exhaust mounts changed the sound but didn't really make it louder or quieter. I'm going to take it to the dealer as they will probably be familiar with the sound and save me another 10 hours trying to locate it!Hi, did you figure it out? I’m having the same issue
Great, please let me know if they find the source of the noise! I feel like it comes from deep inside de dash, so I will try removing the center air vents and the infotainment system. Maybe I will be able to hear more clearly where it’s coming from.Glad to know I'm not the only one. Unfortunately not, I did find that messing around with the exhaust mounts changed the sound but didn't really make it louder or quieter. I'm going to take it to the dealer as they will probably be familiar with the sound and save me another 10 hours trying to locate it!
I'm going in tomorrow to have someone listen to the rattle. I would say it's something loose inside the dash, I'm back at uni now so I don't have the tools or time to be pulling the thing apart sadly. I will let you know the verdict.Great, please let me know if they find the source of the noise! I feel like it comes from deep inside de dash, so I will try removing the center air vents and the infotainment system. Maybe I will be able to hear more clearly where it’s coming from.
Hi mate, check your brake booster hose. It goes from the back right of the motor toward the middle of the cabin. Give it a wobble and see if there's play, if so that's your problem. Just need to stop the plastic clip from wobbling. Mechanic was onto it as soon as I started the car.Great, please let me know if they find the source of the noise! I feel like it comes from deep inside de dash, so I will try removing the center air vents and the infotainment system. Maybe I will be able to hear more clearly where it’s coming from.
Amazing! The noise is completely gone, thanks a lot man!Hi mate, check your brake booster hose. It goes from the back right of the motor toward the middle of the cabin. Give it a wobble and see if there's play, if so that's your problem. Just need to stop the plastic clip from wobbling. Mechanic was onto it as soon as I started the car.
View attachment 107390
No worries mate, I'm pretty chuffed. It was too easy hahaAmazing! The noise is completely gone, thanks a lot man!
Exactly! I fixed it in 5min using a rubber bandNo worries mate, I'm pretty chuffed. It was too easy haha
hey, i'm looking to fix this issue on my car too. could you show how you used the band to keep it in place? i'm just struggling to visualise it myself haha
Hi, let me show you some pictures.hey, i'm looking to fix this issue on my car too. could you show how you used the band to keep it in place? i'm just struggling to visualise it myself haha
This is the plastic clip that is rattling:
If you look behind the fire retardant material, you will see it clips into the body of the car:
I put the elastic band between the clip and the body of the car. It's hard to see, but if you pay attention you will see a blueish thing between them:
Hope it helps!
absolutely amazing, thank you so much!Hi, let me show you some pictures.
This is the plastic clip that is rattling:
View attachment 107623
If you look behind the fire retardant material, you will see it clips into the body of the car:
View attachment 107624
I put the elastic band between the clip and the body of the car. It's hard to see, but if you pay attention you will see a blueish thing between them:
View attachment 107625
Hope it helps!
1 - 14 of 14 Posts
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