Hi there,

 

I've practically done everything imaginable to my fiesta. Changed the timing belt, clutch, suspension arms etc. But I am fully defeated by this metallic bubbling coming from the engine when I come off the throttle. It gets worse at higher revs and happens for about 2-3 seconds before settling as normal. I'm not having any performance issues, still drives amazing, just this noise. It's a 2003 1.4 Fiesta, 89k miles.

 

I suspect I have a slight exhaust leak. I have filled the slight cracks in the stock backbox, and I sprayed the entire exhaust with soapy water to look for more holes. I did notice after doing this that the exhaust started to smoke (I imagine the water had managed to get in somewhere and was being heated inside), again I suspect it is around the flexi pipe. I really don't have a clue what it could be, nor if it is something that needs sorting. I will have to drive a long way to work soon, everyday, so ideally I need to fix this issue before next week if it is urgent.

 

I've got two videos of the sound, if you listen for when I come off the throttle there is a slight metallic gurgle or bubbling. (It's quite hard to hear on the video but is very noticeable inside the car)

 

I appreciate any help, cheers guys 

 

Video 1: 

Video 2: 

 

 

 

Can anyone help with this please? I have bought some aluminium tape as tomorrow I'm going to properly check for an exhaust leak and apply a temp fix for it. If I don't find anything or solve the problem then I'll be back to square 1!

Honestly, I can't hear anything unusual on the video.  Hopefully it will be cured by the exhaust repair.

1 minute ago, TomsFocus said:

Honestly, I can't hear anything unusual on the video.  Hopefully it will be cured by the exhaust repair.

Cheers mate, its quite loud inside the car to be honest, especially when letting off at higher revs. The phone mic wasn't able to pick it up nicely unfortunately. I am just a bit worried about having to drive 100 miles a day to and from work with a noise, it doesn't change the performance at all or feel any different, its literally just a noise.

57 minutes ago, 4RD said:

Can anyone help with this please?

Hi Kyran (got your message 😉)

Like Tom, I can't quite make out any particular noise on the video even with my laptop volume up to max. I do notice a vibration and a very slight, what looks like a judder when you lift off the throttle. I would suspect an engine mount or probably the gearbox mount as being the cause. You would definitely get a noise from a failed mount.

As far as the possible exhaust leak is concerned I don't think it will be the cause of your noise when decelerating. You would be more likely to get noise when accelerating hard from a hole or crack in the exhaust pipe. Also usually you will see a black/sooty deposit on the pipe around any cracks

  I've had many, many Fiesta Mk6 in the family and they are bomb proof cars. Get the mounts checked out, and don't worry, just get the oil regularly changed and keep an eye on the coolant level and you should be fine. 

26 minutes ago, unofix said:

Hi Kyran (got your message 😉)

Like Tom, I can't quite make out any particular noise on the video even with my laptop volume up to max. I do notice a vibration and a very slight, what looks like a judder when you lift off the throttle. I would suspect an engine mount or probably the gearbox mount as being the cause. You would definitely get a noise from a failed mount.

As far as the possible exhaust leak is concerned I don't think it will be the cause of your noise when decelerating. You would be more likely to get noise when accelerating hard from a hole or crack in the exhaust pipe. Also usually you will see a black/sooty deposit on the pipe around any cracks

  I've had many, many Fiesta Mk6 in the family and they are bomb proof cars. Get the mounts checked out, and don't worry, just get the oil regularly changed and keep an eye on the coolant level and you should be fine. 

I gave the main top mount a good nip yesterday, but I'll definitely check out the gearbox mount tomorrow. Going to just give it one last inspection tomorrow, as soon as that's done I'll sign it off and like you said just maintain the condition of the car and trust its reliability. Thanks for the reply mate!

1 hour ago, 4RD said:

maintain the condition of the car and trust its reliability

Bomb Proof : - ) I second that, and doubt Ford will ever make anything as good as this model again.  Please keep posting stuff, it's good to hear how other 2003 1400s used as daily drivers survive when looked after.

57 minutes ago, Marineboy said:

Bomb Proof : - ) I second that, and doubt Ford will ever make anything as good as this model again.  Please keep posting stuff, it's good to hear how other 2003 1400s used as daily drivers survive when looked after.

Ahh I appreciate it mate! I absolutely love this car to pieces. It is an absolute joy to work on, so much space in the engine bay and its all just straight forward mechanics inside. I'll keep posting updates with it, I'm looking forward to upgrading it in the near future after completing a year with a black box. 

It does sound a bit loud, are you sure the exhaust is standard?

21 minutes ago, DaveT70 said:

It does sound a bit loud, are you sure the exhaust is standard?

Yeah it’s definitely standard mate, it almost is like an aftermarket exhaust would splutter noises after revving but almost like it’s from the front end rather than the back. I’m having a look in a little while, got to sort a drive shaft oil leak so while I’m there I’ll check thoroughly for any leaks and temporarily fix them. Will report back with anything I do or don’t find.

Perhaps it's the exhaust flexi pipe???

Yeah I’m checking that over today, the car runs so well so I’m not concerned too much, it’s just a matter of finding the noise! Like you said the flexi pipe is my main concern

Had to fit a new seal for my drive shaft and noticed a few things. One bolt on the gearbox mount needed tightening a good bit more. But the main sound was definitely coming from the point between the mid section of the exhaust and the down pipe, not the flexi. I assume last time I must have sprayed here accidentally because of the lack of room and after doing it again today and covering the exhaust slightly I could see bubbles coming out of that area. A bit of paste has seemed to dull the noise quite significantly, so I think if I tighten the down pipe meeting the mid section a little more and use a tiny bit of paste the noise will be gone.

 

Cheers all for your help, I really appreciate it.