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Strange Vibrating Sound From Engine Bay When Accelerating


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#1 gronkjor

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Posted 09 November 2010 - 04:00 PM

Hi
My Mini Cooper 1998 has evolved a strange sound from the engine bay when i am accelerating. It sounds a bit like it is vibrating against something. Also sometimes when i release the accelerator pedal there is a "klonking" noise from the engine bay. What could be causing the problems?

Cheers
Rasmus

#2 L400RAS

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Posted 09 November 2010 - 07:30 PM

The klonk may be top engine steady bushes have worn. With the hand brake on tight, bonnet up, kneel in front of the car, grap the rocker cover, push and pull the engine. Look for movement in the top arm - connects to the left of the cylinder head and connects to the bulkhead. If movement here, replace bushes. One some really bad ones, you can make the same knock noise as you hear when driving. Another test is to get an assistant to rev the car from 1000 - 3000 rpm wuickly, while watching the engine. If hte engine moves excessively, this points to hte bushes also.

#3 gronkjor

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Posted 11 November 2010 - 05:21 PM

The klonk may be top engine steady bushes have worn. With the hand brake on tight, bonnet up, kneel in front of the car, grap the rocker cover, push and pull the engine. Look for movement in the top arm - connects to the left of the cylinder head and connects to the bulkhead. If movement here, replace bushes. One some really bad ones, you can make the same knock noise as you hear when driving. Another test is to get an assistant to rev the car from 1000 - 3000 rpm wuickly, while watching the engine. If hte engine moves excessively, this points to hte bushes also.



Thank you. Tried to find any movement in the rocker cover, but it dos not seems like it is moving. The "klonk" sound is also rare, but the vibrating sound is there almost all the time. Pretty strange the sound just suddenly started a couple of days ago. It´s like the engine is vibrating towards the bodywork, but i am not really sure. It´s worst when i am in 2-3 gear around 2000-3000 rpm. If i am lucky the sound will disappear by itself - you never know with Minis :(

#4 gronkjor

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Posted 15 December 2010 - 10:55 AM

The klonk may be top engine steady bushes have worn. With the hand brake on tight, bonnet up, kneel in front of the car, grap the rocker cover, push and pull the engine. Look for movement in the top arm - connects to the left of the cylinder head and connects to the bulkhead. If movement here, replace bushes. One some really bad ones, you can make the same knock noise as you hear when driving. Another test is to get an assistant to rev the car from 1000 - 3000 rpm wuickly, while watching the engine. If hte engine moves excessively, this points to hte bushes also.


Hi
changed the engine steady bushes and fitted an extra lower steady. That helped on the "klonk" issue O_O
But the vibrating sound is still there. Its when i am driving at around 1900-2100 rpm and it gets even worse if i hit a hole or something. Do you guys have any ideas of what it might be?

#5 Teapot

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Posted 15 December 2010 - 12:59 PM

This vibrating ... is it metallic? Does it vary with engine speed? And it occurs only when you're moving and in gear? Can you and a passenger agree on the direction it's coming from?
It's not a disc dust cover, is it?

#6 gronkjor

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Posted 15 December 2010 - 01:08 PM

This vibrating ... is it metallic? Does it vary with engine speed? And it occurs only when you're moving and in gear? Can you and a passenger agree on the direction it's coming from?
It's not a disc dust cover, is it?


Yes it is metallic. It only occurs when i am moving and in gear and especially at 1900-2100 rpm. We cannot figure out where it is coming from, but somewhere in the front of the car O_O
Disc dust cover? How can i check that?

Appreciate your help :ohno:

#7 minisilverbullet

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Posted 15 December 2010 - 01:09 PM

Forgive me for this post, but ...... I had a vibration form the engine and found it was actually the bonnet stay, I just taped it secure to the bonnet!

#8 Teapot

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Posted 15 December 2010 - 04:12 PM

Disc dust cover? How can i check that?

If you've got them, there's one on the inside of each brake disc. They sometimes come loose or the clamps break and they rattle. You can ditch them since they aren't essential. A quick check may eliminate them as the cause of your rattle.

Edited by Teapot, 15 December 2010 - 08:43 PM.


#9 robnjen

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Posted 15 December 2010 - 05:18 PM

I have the same problem at certain revs - at fast idle it rattles and vibrates. when driving it comes and goes - at fast idle I can stop it by getting out and putting pressure on the bonnet, but can't do this when I am driving!!!

If it vibrates when parked at a certain engine speed, have someone press down on the bonnet - at least you will be able to eliminate this.

#10 Teapot

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Posted 15 December 2010 - 08:45 PM

It's amazing how many more high-frequency noises Huey makes since I got hearing aids. O_O I thought I had them all pinpointed but now I've had to start again.

#11 gronkjor

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Posted 15 December 2010 - 09:25 PM

It's amazing how many more high-frequency noises Huey makes since I got hearing aids. :ohno: I thought I had them all pinpointed but now I've had to start again.


Thanks for your answers lads, will have a look at it tomorrow.

Oh yeah with a Mini it might be better to have poor hearing, it would certainly spare you for a lot of worrying thoughts. O_O

#12 gronkjor

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Posted 25 April 2011 - 09:09 PM

Okay little update on this minor problem : Noise is still there. engine steady bushes where worn and is changed - which removed the "klonk". Wheel bearings where worn and is also changed. I thought that it would solve the rattling noise - but it is still there. The disc covers is also removed. I am pretty sure that it isn't just the bonnet which is vibrating as it can be very noisy. :thumbsup:
Any more ideas?

#13 samsteryfc

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Posted 27 April 2011 - 11:32 AM

I have the vibrating problem on mine aswell... Seems to be coming from R/H bulkhead area behind dash, and mine happens when I press the pedal flat to the floor in top gear at 1900ish... Its just a constant drone when I am crusing along.. Really annoying..

#14 Chris_R

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Posted 27 April 2011 - 11:54 AM

I have the vibrating problem on mine aswell... Seems to be coming from R/H bulkhead area behind dash, and mine happens when I press the pedal flat to the floor in top gear at 1900ish... Its just a constant drone when I am crusing along.. Really annoying..


It's not the plastic steering column surround vibrating is it?

#15 Nu2mini

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Posted 27 April 2011 - 12:12 PM

I have the vibrating problem on mine aswell... Seems to be coming from R/H bulkhead area behind dash, and mine happens when I press the pedal flat to the floor in top gear at 1900ish... Its just a constant drone when I am crusing along.. Really annoying..


Check to see it's not the speedo cable rattling. Best way is to reach underneath steering column, behind the dash and just see if you can move things around behind speedo. No need to be too rough just try to shake the cable and anything else behind there a little. Then take it for a test drive and see if it's changed at all. Sometimes you can sort a rattling speedo cable just by moving it. Othertimes you may have take the dash out to fix whats rattling.




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