junglism32

Knocking noise when accelerating - NOT rear engine mount

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Hi everyone,
Sorry if this is a repeat post but I can't seem to find anyone with quite the same problem as this. I've developed a quite loud "knock" or "clunk" when taking off or accelerating abruptly in 1st, 2nd and even 3rd at times. I just replaced the rear engine mount and this didn't solve the problem. I can feel it almost directly under my feet in the footwell when it happens. It doesn't happen if I drive very carefully and accelerate very slowly, nor does it happen when going over bumps or any other time other than fast acceleration. I can pump the gas pedal and make it clunk nearly on command once I've released the clutch nearly all the way. It doesn't do it in neutral either as I tried to watch the engine in neutral and as a friend drove it and i walked alongside the car. It doesn't vibrate much other than rough idle a bit either. If anyone has any ideas I'm running out of them! Thanks in advance.

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Sounds similar to what was going on with my car. Very loud clunk or knocking when taking off quickly from a stop.

What it ended up being in my case was a broken exhaust bracket, the one right under the engine had snapped and was letting the downpipe smack off the subframe.

Hope this might help!

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I had this exact issue, mine was also a snapped exhaust bracket! Unfortunately it’s the section of exhaust that has the cat (most expensive but to replace). I just put a jubilee clip on there, holds nicely and passed the mot as an advisory! 

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Yep, sounds like it might be a common issue. Luckily enough, my local mechanic was able to weld mine back together, been fine since and a whole lot cheaper at £30 than getting a new Manifold, Cat and downpipe (All one piece!) at over £300! 

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9 hours ago, Paddy94 said:

Yep, sounds like it might be a common issue. Luckily enough, my local mechanic was able to weld mine back together, been fine since and a whole lot cheaper at £30 than getting a new Manifold, Cat and downpipe (All one piece!) at over £300! 

Not if you get it here http://www.cats2u.co.uk/Catalytic-Converters/FORD+FOCUS+1.8

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Thanks guys, I did notice one of the brackets had rusted off the exhaust when I was under there changing the rear engine mount. It does seem much louder than this but it could easily just be getting amplified. I will report back. Cheers.

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On 21/04/2018 at 7:32 PM, Paddy94 said:

Sounds similar to what was going on with my car. Very loud clunk or knocking when taking off quickly from a stop.

What it ended up being in my case was a broken exhaust bracket, the one right under the engine had snapped and was letting the downpipe smack off the subframe.

Hope this might help!

+1

I had exactly the same issue on the wife's MK2.5 1.8 Zetec.

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19 minutes ago, Stuart Pinsent Crisp said:

I have the same noise but not the bracket, replaced both drive shafts and wishbones not the wheel bearings. Any idears focus 2007 auto

Is it definitely from the front? When my rear upper arm bushes went it would transfer the noise through and would seem like it was the front.

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I have the same: 2008 focus replaced with new lower arms, dog bone and drive shafts - none of these have solved the clunk. Everything seems good on suspension, no engine vibration. Any previous posts solve this issue ?

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Same on my 2003 focus 2.0L, sedan.  Makes a knocking, and loud clicking, rattling noise under acceleration.  Struts, axle shafts, sway bar end links been replaced.  Next is going to be ball joints and tie rod ends.  Haven't checked the exhaust though.

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I had similar on my old 2005 focus when one of the rubbers at the rear of the exhaust was snapped. It gave the whole exhaust system enough play to knock loudly towards the front of the car.

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Mine is doing the same but does it in 4th as well.  Has anybody resolved this ? 

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Hi, i have what i think is exactly the same issue, when pulling away and changing up thru 2nd and 3rd gears, but not really noticed in 4th upwards, but yes a loud clunking noise on engaging the throttle after gear change, also when just rolling in traffic in any of these lower 3 gears and just tapping on the throttle, clunk clunk clunk, very annoying, its the second st180 i have had so i compare everything to the previous one that had no noise whatsoever. Have had droplinks, front drivers mount and drivers side drive shaft (which had 3-4mm play) all replaced, rear engine mount and all brakes checked and the problem still persists, am now going for new brake discs, hoses and caliper guider slider pins as i know the brakes are a bit low and discs corroded on edges so they need doing but also will see if there is a difference, if its still there then i will have the whole exhaust system checked, mountings, brackets and heatshields as i have heard these can all be symptoms, but if anyone has any ideas then be glad for the input.

Cheers, Simon.B

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Hi did any one solve this I have the same problem and have replaced everything 

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On 8/14/2019 at 5:56 AM, Jinks said:

Hi did any one solve this I have the same problem and have replaced everything 

I had a cluck that turned out to be play in the drivers side driveshaft. Would make a clunk noise just once when pulling away or when accelerating. 

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The front exhaust mount from the down pipe is most likely to be at fault, usually the hanger will rust through and drop lower but still 'look' okay without having it jacked up and being able to get a proper shove on it.

Majority of Focus 'clunks' when accelerating end up being that bounty allowing the jerk of the car to shift the down pipe just enough for it to knock the sub frame, making it sound a heck of alot worse that it actually is.

20 quid at a local to weld'erup should do it if that's the case!

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On 8/17/2019 at 9:31 PM, WireyWhenWet said:

The front exhaust mount from the down pipe is most likely to be at fault, usually the hanger will rust through and drop lower but still 'look' okay without having it jacked up and being able to get a proper shove on it.

Majority of Focus 'clunks' when accelerating end up being that bounty allowing the jerk of the car to shift the down pipe just enough for it to knock the sub frame, making it sound a heck of alot worse that it actually is.

20 quid at a local to weld'erup should do it if that's the case!

Yup, my wife's MK2.5 Zetec 1.8 HE was making a right racket and it turned out to be a simple rotted exhaust hanger.

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Soz for late reply found my problem after 3 sets of drive shafts I used good strength lock tight and the splines and inserted into hub and guess what no knocking lol 

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But now have new problem when I get to 80 90 ish in 4th the spn light comes on I saying mass sensor I have replaced it but still happens can the map sensor throw up that fault I no they both work on measuring air any ida thanks 

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