Technical Need help identifying noise

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Technical Need help identifying noise

Moudubou

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Hello everyone.

I need help to identify a very alarming noise coming from the front-left of the car.
The noise appeared after a mechanic had to remove the crossrail (Subframe).

For exemple, I can make the sound repeat like 'bing-bang bing-bang bing-bang...' if I press and release the gas pedal repeatedly.


I can hear the noise when I accelerate or break, or if I suddenly stop accelerating.
It's like a 'bang' sound or a creaking sound.


Do you have any idea or do you need more info ?
I will try to record it next time.

Thanks a lot for your help because I really can't figure where this sound is from.
 
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Hello everyone.

I need help to identify a very alarming noise coming from the front-left of the car.
The noise appeared after a mechanic had to remove the crossrail (Subframe).

For exemple, I can make the sound repeat like 'bing-bang bing-bang bing-bang...' if I press and release the gas pedal repeatedly.


I can hear the noise when I accelerate or break, or if I suddenly stop accelerating.
It's like a 'bang' sound or a creaking sound.


Do you have any idea or do you need more info ?
I will try to record it next time.

Thanks a lot for your help because I really can't figure where this sound is from.

Hi,
I've recently changed the subrame and wishbones on my 04 mk2b.
I would suggest that you check that the mounting bolts for the subframe are torqued up, also the pinch bolts at the balljoints, and all the anti roll bar bushes as everything should be gone through after the car is back on the ground and everything has settled.
Good luck.
 
Hello everyone.

I need help to identify a very alarming noise coming from the front-left of the car.
The noise appeared after a mechanic had to remove the crossrail (Subframe).

For exemple, I can make the sound repeat like 'bing-bang bing-bang bing-bang...' if I press and release the gas pedal repeatedly.


I can hear the noise when I accelerate or break, or if I suddenly stop accelerating.
It's like a 'bang' sound or a creaking sound.


Do you have any idea or do you need more info ?
I will try to record it next time.

Thanks a lot for your help because I really can't figure where this sound is from.

On the left hand side of subframe about where your brake pedal is there should be a removeable aluminium 'dog bone' link between the subframe and the gearbox. If that is missing or loose the engine will move back and forwards making the kind of noise you are describing as you push the gas pedal up and down.

Also if you look under the front wheel you will see under the car there is a triangular device that holds the part the wheel is fixed to onto the subframe. That triangular part is held by two bolts on the subframe. If the rear part is broken or loose you are going to get a similar kind of noise.
 
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Thanks a lot for your help !

So I checked the bolts and some of them were not tightened enough. The dogbone and the triangle seems fine too.

But ! It seems thats one bolt is missing on the subframe !


190413043819943953.png


190413043821127275.jpg


Can you help me to identify the missing bolt to buy it again from fiat ? :)

I guess it's the number 5 but I'm not sure,
 
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Thanks a lot for your help !

So I checked the bolts and some of them were not tightened enough. The dogbone and the triangle seems fine too.

But ! It seems thats one bolt is missing on the subframe !


190413043819943953.png


190413043821127275.jpg


Can you help me to identify the missing bolt to buy it again from fiat ? :)

I guess it's the number 5 but I'm not sure,

From your picture it looks like 5 is already present holding the anti roll bar bush.

5 is a short bolt whereas 3 is a long bolt that passes through the subframe and screws into the metal above the subframe.
 
From your picture it looks like 5 is already present holding the anti roll bar bush.

5 is a short bolt whereas 3 is a long bolt that passes through the subframe and screws into the metal above the subframe.

Thanka for your answer. So it would be the same bolt as 3 ?

Because there is a bolt missing, and on the other side the bolt is present
 
Thanks I will buy it.

Is it normal that I have 3 bolts on each side of the mainframe ?

A picture is easier.

The subframe is held to the car by the 6 red circled bolts.

The triangular wishbones are held by the 4 blue bolts

The anti roll bar is held by the 4 green bolts

The Aluminium steering rack is held by the 2 yellow bolts
 

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  • subframe bolts.png
    subframe bolts.png
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A picture is easier.

The subframe is held to the car by the 6 red circled bolts.

The triangular wishbones are held by the 4 blue bolts

The anti roll bar is held by the 4 green bolts

The Aluminium steering rack is held by the 2 yellow bolts

Thanks ! This picture is very informative ! I edited your picture to show with an arrow the missing bolt.


19041412030965473.jpg


So red bolts are number 3, and part number 46790292. Am I right ?


Thanks a lot for your help. I need the car so I will still drive with the missing bolt but I will replace it ASAP !


Other question : Is it safe to jack up the car on the mainframe ?
 
Thanks ! This picture is very informative ! I edited your picture to show with an arrow the missing bolt.


19041412030965473.jpg


So red bolts are number 3, and part number 46790292. Am I right ?


Thanks a lot for your help. I need the car so I will still drive with the missing bolt but I will replace it ASAP !


Other question : Is it safe to jack up the car on the mainframe ?

I am pretty sure all of those red bolts are the same size and are number 3 and that is the part number for number 3.


I always jack up my car on the outer red bolt.
 
Thanks for your help. So the bolts were the right size ! :)

Unfortunately the noise is still here and I am totally clueless now...
 
So I finally found where the noise is from... It is from the dogbone screw attaching it to the mainframe !

And the dowbone screw is almost totally loose now !! I checked but it is tightly screwed but still move.... I stopped driving the car for now, do you have any idea what I should do ?

Thanks a lot.
 
So I finally found where the noise is from... It is from the dogbone screw attaching it to the mainframe !

And the dowbone screw is almost totally loose now !! I checked but it is tightly screwed but still move.... I stopped driving the car for now, do you have any idea what I should do ?

Thanks a lot.

i think you are missing that fat washer between top dogbone mount side and subframe
 
So I finally found where the noise is from... It is from the dogbone screw attaching it to the mainframe !

And the dowbone screw is almost totally loose now !! I checked but it is tightly screwed but still move.... I stopped driving the car for now, do you have any idea what I should do ?

Thanks a lot.

What do you mean the screw is tightly screwed but still loose? Are you saying it is firmly fixed into the subframe but is rotating with the spanner?

I think there is a threaded captive tube inside the subframe for that bolt. If the tube has broken away you are going to have to grind off the head of the bolt and remove that tube and then see what condition the subframe is before seeing how to repair it.

If you cannot turn the bolt then that fat washer frisko mentioned could be missing or you need to remove the bolt and clean up the threads. The bolt is incredibly tight. Torque is 120nm and with a bit of rust it is the mother of all bolts to tighten.
 
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What do you mean the screw is tightly screwed but still loose? Are you saying it is firmly fixed into the subframe but is rotating with the spanner?

I think there is a threaded captive tube inside the subframe for that bolt. If the tube has broken away you are going to have to grind off the head of the bolt and remove that tube and then see what condition the subframe is before seeing how to repair it.

If you cannot turn the bolt then that fat washer frisko mentioned could be missing or you need to remove the bolt and clean up the threads. The bolt is incredibly tight. Torque is 120nm and with a bit of rust it is the mother of all bolts to tighten.


The screw is tightly screwed and I can't screw it more. But the screw can move back en forth when the dogbone is pushing or pulling it.


Here's a (poorly made drawing to explain what I think is happening)

190520093720544325.png
 
What do you mean the screw is tightly screwed but still loose? Are you saying it is firmly fixed into the subframe but is rotating with the spanner?

I think there is a threaded captive tube inside the subframe for that bolt. If the tube has broken away you are going to have to grind off the head of the bolt and remove that tube and then see what condition the subframe is before seeing how to repair it.

If you cannot turn the bolt then that fat washer frisko mentioned could be missing or you need to remove the bolt and clean up the threads. The bolt is incredibly tight. Torque is 120nm and with a bit of rust it is the mother of all bolts to tighten.

Merde! It sounds like you will need to weld the subframe to fix that movement
 
Paska ! I see a mechanic friend tomorrow and I will keep you in touch ! :)
 
Double post to ask for a simple question :


What type of subframes are compatible with my car ? I guess I will try to get a new one in a Wrecking yard.


Thanks a lot for your help.
 
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