Odd Strong Vibration at 2500rpm

psilentp · 19-10-2009, 02:00 PM

I was driving in to work today and it seems that my car has developed a bizarre vibration under specific conditions.

The sound is quite loud and difficult to pinpoint, it sounds a bit like the moo of a cow in pitch and is also very similar in sound to when your mobile vibrates on a table

it only occurs when decelerating either with or without brakes, it stops as soon as i hit the thottle again. and it only occurs between 2500 and 2300.

it only does it when the clutch is engaged, does it in all gears. couldn't test neutral cause the engine sweeps through the range too fast i think

I have a 99 BJ Astina 1.6

anyone have any clue as to what it could be?

Rupewrecht · 19-10-2009, 02:06 PM

Might be a broken/torn rear engine mount.

chicaboo · 19-10-2009, 02:06 PM

I had something like that when my flywheel had a bad "hotspot" on it [causes it to become unbalanced]. It happened at about the same revs too. It might be that in conjunction with a buggered driver's side engine mount.

Gav.

project.r.racing · 19-10-2009, 02:09 PM

trust bearing
rear engine mount
inner rhs cv joint

all these cause vibrations when decelerating.

psilentp · 19-10-2009, 04:56 PM

Quote:

Originally Posted by project.r.racing

trust bearing
rear engine mount
inner rhs cv joint

all these cause vibrations when decelerating.

None of these sound cheap or easy to fix :/

psilentp · 19-10-2009, 05:43 PM

at 160000ks it could be any of those hehe or more

project.r.racing · 19-10-2009, 05:48 PM

Quote:

Originally Posted by psilentp

at 160000ks it could be any of those hehe or more

correct.

the bearing tends to make a squeeling sound tho.
the inner cv joint a very light clicking sound.

so maybe it is the rear or drivers side mount???

chicaboo · 19-10-2009, 07:34 PM

Either the driver's side or rear mount will be buggered by 160k kms, but the drivers side mount will move more [but less often] than the rear mount when rooted. Mad Matt has just gone through repairing both of these, so he might have some comments.

When my flywheel was out of balance, I had a distinct whirring sound in addition to the vibrations at certain rev ranges when I used the clutch. This turned out to be the throw-out bearing having worn out from the vibrations.

Gav.

psilentp · 20-10-2009, 10:44 AM

Quote:

Originally Posted by project.r.racing

correct.

the bearing tends to make a squeeling sound tho.
the inner cv joint a very light clicking sound.

so maybe it is the rear or drivers side mount???

Yeah i was thinking similar things in regards to the noises.

will give it a thorough looking over tonight

psilentp · 20-10-2009, 10:47 AM

Quote:

Originally Posted by chicaboo

Either the driver's side or rear mount will be buggered by 160k kms, but the drivers side mount will move more [but less often] than the rear mount when rooted. Mad Matt has just gone through repairing both of these, so he might have some comments.

When my flywheel was out of balance, I had a distinct whirring sound in addition to the vibrations at certain rev ranges when I used the clutch. This turned out to be the throw-out bearing having worn out from the vibrations.

Gav.

hmm i can't say i've noticed any whirring, it strikes me as odd that it went overnight but i guess such is the nature of cars

phildough · 20-10-2009, 10:10 PM

I've had all the engine and gearbox mounts and lower suspension bushes replaced on my car a few months ago.
It made a huge difference to the way the car drives and removed a lot of weird noises and vibrations.
I cant tell you if my car makes any weird noises around those revs as the air intake and exhaust drown out any noises.

psilentp · 21-10-2009, 12:28 AM

i intend to get to that stage

phildough · 21-10-2009, 01:06 AM

Dont buy a cannon for an exhaust. You will regret it
I do.
Every time im in the car.

psilentp · 21-10-2009, 10:18 AM

Quote:

Originally Posted by phildough

Dont buy a cannon for an exhaust. You will regret it
I do.
Every time im in the car.

No chance, i spend too much time laughing at those who have them ;P

19-10-2009, 02:00 PM	#1
psilentp Junior Member Join Date: Apr 2009 Location: Perth West Australia Car: 323 Astina Hatch '99 Posts: 239	Odd Strong Vibration at 2500rpm I was driving in to work today and it seems that my car has developed a bizarre vibration under specific conditions. The sound is quite loud and difficult to pinpoint, it sounds a bit like the moo of a cow in pitch and is also very similar in sound to when your mobile vibrates on a table it only occurs when decelerating either with or without brakes, it stops as soon as i hit the thottle again. and it only occurs between 2500 and 2300. it only does it when the clutch is engaged, does it in all gears. couldn't test neutral cause the engine sweeps through the range too fast i think I have a 99 BJ Astina 1.6 anyone have any clue as to what it could be?

19-10-2009, 02:06 PM	#2
Rupewrecht Administrator Join Date: Mar 2002 Location: melb.vic.au Car: AZ-1, Astina Hardtop Turbo, BJ Protege, Beetle Posts: 16,525 View Photos By: Rupewrecht	Might be a broken/torn rear engine mount. __________________ jdmparts.rupewrecht.com Sourcing your not-quite-overnight parts from Japan WRECHT--\|--SLOWTEGE--\|--BEETLE--\|--SUBSTITUTE--\|--AZ-1

19-10-2009, 02:06 PM	#3
chicaboo Senior Member Join Date: Sep 2004 Location: Logan prefecture Car: Touge monster Posts: 7,585	I had something like that when my flywheel had a bad "hotspot" on it [causes it to become unbalanced]. It happened at about the same revs too. It might be that in conjunction with a buggered driver's side engine mount. Gav.

19-10-2009, 02:09 PM	#4
project.r.racing Senior Member Join Date: Sep 2004 Location: n/a Car: n/a Posts: 10,929	trust bearing rear engine mount inner rhs cv joint all these cause vibrations when decelerating.

19-10-2009, 05:43 PM	#6
psilentp Junior Member Join Date: Apr 2009 Location: Perth West Australia Car: 323 Astina Hatch '99 Posts: 239	at 160000ks it could be any of those hehe or more

19-10-2009, 07:34 PM	#8
chicaboo Senior Member Join Date: Sep 2004 Location: Logan prefecture Car: Touge monster Posts: 7,585	Either the driver's side or rear mount will be buggered by 160k kms, but the drivers side mount will move more [but less often] than the rear mount when rooted. Mad Matt has just gone through repairing both of these, so he might have some comments. When my flywheel was out of balance, I had a distinct whirring sound in addition to the vibrations at certain rev ranges when I used the clutch. This turned out to be the throw-out bearing having worn out from the vibrations. Gav.

20-10-2009, 10:10 PM	#11
phildough Banned Join Date: May 2006 Location: Brisneyland, Queensland Car: 2002 Mazda Frankenstina Posts: 2,868 View Photos By: phildough	I've had all the engine and gearbox mounts and lower suspension bushes replaced on my car a few months ago. It made a huge difference to the way the car drives and removed a lot of weird noises and vibrations. I cant tell you if my car makes any weird noises around those revs as the air intake and exhaust drown out any noises.

21-10-2009, 12:28 AM	#12
psilentp Junior Member Join Date: Apr 2009 Location: Perth West Australia Car: 323 Astina Hatch '99 Posts: 239	i intend to get to that stage

21-10-2009, 01:06 AM	#13
phildough Banned Join Date: May 2006 Location: Brisneyland, Queensland Car: 2002 Mazda Frankenstina Posts: 2,868 View Photos By: phildough	Dont buy a cannon for an exhaust. You will regret it I do. Every time im in the car.