rattling noise under acceleration

[tony08hooper]

Hi everyone,

I have been struggling lately to locate a new noise i have coming from the car,

What it sounds like is a very distinctive rattling sound coming from the front of my car.

What i have noticed is that it only does it under these circumstances :

. when my foot is on the accelerator pedal ( accelerating )

. driving slightly uphill

. high gear with low rev range

. noise always stops when i take my foot off the pedal

I believe the noise started when i had my air suspension fitted, But i cannot be sure, I have located the noise to be coming from behind the dash, untill the other day when i heard it with the window down, and can hear it coming from outside of the vehicle very clearly..

I have been under the vehicle checking for any loose/touching parts and everything seems okay

I am stumped, but desperate to fix it.

Any ideas?

Tony

 

[nd-photo.nl]

Do you have the original downpipe/catalyst?

 

[Bouncerbeater]

Not detonation is it ? Prob not with all the electronics nowadays.

 

[tony08hooper]

hi guys,

yeh the car is completely standard when it comes to the mechanics of the car, the only thing ive changed is the suspension and a dump valve.

dont think its detonation matey no. it only occurs when im going slighlty uphil and with my foot on accelerator. so odd

 

[sockpuppet]

Is it at specific rev range? I had a rattling at 1400 - 1600 revs, but mine was also when stationary. It turned out to be the rubber mounts on the air filter casing had perished. A couple of washers on the 2 bolts secured the filter housing and stopped the rattling.

 

[tony08hooper]

Hi there, thanks for the reply,

No it doesnt do it when stationary, its so difficult to explain when it occurs, its doesnt usually happen at low rev range, its at its loudest when in 3rd gear, it also makes the noise when im going over a rough surface,

I have a specific hill i drive up when i go home from work, a country lane which is uphill

On this road it where its at its worst, the rattling doesnt stop untill ive reached the top...

Another thing ive found today is that if i kick the clutch into biting point it makes the rattling sound once.

I dont think its the clutch though.. my initial thought was something hitting the bulk head but ive been under the bonnet and underneath checking the steering rack and all sorts..nothing seems loose, lower engine mount is solid as well..

im stuck

 

[Alexis27]

Get it up on a ramp and I'd bet you'd find the problem!

 

[Dave_c85]

Might be something on the aux belt if it sounds like it's coming front right hand side, my car is doing this only when under heavy load like you mention. I think my tensioner is the culprit and booked in early next week I'll let you know what it is.

Other thing to check is exhaust heat shield as mine came off at one side and only rattled under high load due to vibrations etc, worth a look too

 

[tony08hooper]

Hi there,

Tnanks for the replys, I have had it on a ramp twice, No joy.. im doing an oil change this week so wil have another look...

slowly giving up on this car... might be time to buy a jap! lol

 

[wisesmurf]

Exhaust heatshield?

 

[Rivva]

Exhuast manifold gasket

 

[tony08hooper]

righty right... i have been under the car again and have had a long look whilst doing an oil change,

i noticed that the exhaust mount just after the cat has snapped off... as well as the mount just before the back box.. in hopes that this was the cause i bought and fitted a Milltek exhaust.. cat back.

I now have a lovely sounding car, with a shiney exhaust tip... and a still, a rattling sound.

So the exhaust heat shields and the exhaust itself is not the cause.

With this in mind, im half thinking its something to do with my air suspension... possibly an air line rattling behind the dash where they have been routed or something. ive got a week off soon so im going to pull the dash centre part out and see if i can locate the noise