Loud knocking noise from VP

[baldy2004]

Hi guys I only have just joined this site.

I'm wondering whether ne1 would be able 2 help me!!

I own a VP Calais which i have changed to manual (btw its a V6). Its done a fair few K's on it and recently there was a slight knocking (like a jackhammer noise) coming from the engine bay! It was fairly intermittent at first but now its a lot louder and accompanied by a squeaking type noise lately and is fairly consistent. I'm not sure whether both noises are related but I have taken my car to many mechanics and have had a lot of puzzled looks and "i have no idea" comments.

The strange thing is that if you take the belt off the front u can't hear it at all pretty much and everything is very quiet. But as soon as u put the belt on (by having the tensioner bracket hindged up by a ratchet and letting it drop back down the noise comes back and the more tension you put on the belt the louder the noise seems to be! Also if you rev the motor the knocking noise is still there but just gets faster and the slows down again as revs drop (ie dependent on revs)

I got told it could be that tensioner bracket and pulley and i have changed the bracket with no difference in sound and the pulley has already been changed and is still fairly new and been proved not to be the problem neway. The harmonic balancer is of main interest atm as with the timing chain however there is no visual damage to the balancer (ie rubber is fine/no cracks) and if u get a pipe, put ur ear to it and move it around the pullies on the front all of them sound fine until u get to the harmonic balancer area where u can hear a replica of the original noise.

Can some1 please help me!!?? Has anyone come across this before or heard of it

Cheers
baldy2004

[Emackulation]

To me it sounds like youve done a bit of investigating which is good and helpfull for us. Saying that the noise was intensified around the harmonic balancer tells me that you should take it off and have a look behind there for any obvious issues, since you say the noise is pretty frequent and loud I think you will be able to spot the issue.

[Rhino Racing]

Good info mate.
The fact that it is not there withthe belt off suggests it should not be an internal engine/ lifter/ piston or big end drama.
Have u tried doing this with the air con turned off? Maybe it is air con related.
Could be something hitting the impellor of the water pump??? Or a water pump bearing?
Or the idler bearing could be cactus
Or the power steering pump could be stuffed.
Also check that the big nut in the center of your balancer is tight....
and that the locking bolt for the crank angle sensor is not loose as i have seen one come loose and hit the interupter blades on the inside of the pulley.

[Bz Kn33z]

With the Harmonic balancer the front of it could be fine like no cracks and chucks taken out but the back could be worse, to be it just sounds like a Big end but could be wrong, good luck.

[baldy2004]

Mack that is a good idea and cheers for the reply.

Rhino Racing the noise is being made when the air con is turned off, I have swapped ova the altenator with no difference, changed the idler pulley bracket and just tested out the idler pulley with a spare with also no change to the sound, as for the power steering & water pump I would highly doubt them as being the problem as the noise is definately pin pointed to the bottom around the harmonic balancer area, but cheers for the advice.

Bz Kn33z i highly doubt it being the bottom end bearing correct me if i'm wrong but wouldn't the noise be heard all of the time ie when the belt is not running on the front, but u have also made a good point about the harmonic balancer not necessarily being cracked on the front to be broken!

Also guys I have also noticed that this noise is not as bad when cold its only when the motor warms up it is much louder!!!

Cheers
baldy2004

[PaRaDoX]

sounds like to me you have a shagged bearing somewhere on the fan belt, heres what to do!

grab the biggest screw driver u can find, put the sharp end at the point where u think the noise is comming from, and place the handle against your ear firmly, you should beable to hear the uber workings of your engine place the sharp end at diffrent points till you find the pesky noise

[Just_a_stocker]

water pump?

[greenfoam]

The sounds you describe seems like the balancer, but normally they look obvious and move around

[Bz Kn33z]

H Balancer still spins around when car is on, so the bearing is going around to isnt it. correct me if i am wrong.

[Bz Kn33z]

What oil are you running in it to is it thin?

[burnz]

could it be a midjet with a hammer?

[markovr]

The inner and outer part of the balancer are actually joined to each other by a sealed bearing and bonded with rubber between the outer and inner hub...on the outside of the hub is a large tag that sits very close but does not touch to the outer part that the belt runs on...when the rubber perishes and the balancer gets sideplay and now it allows the tag to hit the outer part and the noise is it hitting as tension is put on that side on every rotation. It sounds like hell has broken loose but it cant come off but should be replaced asap

[baldy2004]

Hey guys, cheers for all the feedback.

I bought a new harmonic balancer the other day (there are two types for a VP) n when i went to sprint auto parts i told em the month and year of my car and they gave me the earlier one bcoz mine was made in Oct 92 and the earlier one when up to the end of 92 only to find out i had the wrong one because the gap in the metal ring at the back was too small for my crank angle sensor to fit, so I had to get the new one,

Anyway after all that i got it changed over and she is quiet as now!! so problem solved! i now have to get used to the motor being so quiet!! looking at the stuffed one there were tiny cracks on the outside of the rubber, but not many tell tale signs!

[Emackulation]

Hey guys, cheers for all the feedback.

I bought a new harmonic balancer the other day (there are two types for a VP) n when i went to sprint auto parts i told em the month and year of my car and they gave me the earlier one bcoz mine was made in Oct 92 and the earlier one when up to the end of 92 only to find out i had the wrong one because the gap in the metal ring at the back was too small for my crank angle sensor to fit, so I had to get the new one,

Anyway after all that i got it changed over and she is quiet as now!! so problem solved! i now have to get used to the motor being so quiet!! looking at the stuffed one there were tiny cracks on the outside of the rubber, but not many tell tale signs!

Glad to hear you got it sorted! I think you had it pretty sussed out in the first place, well done.