Who here owns a Renaultsport?

alexisonfire · 2 Feb 2011 at 19:03

Exhaust sounds awesome, but.....

Copied my post straight from CS incase some one here has heard of this before...

Only had the damn car a couple of days and already got problems

Driving over to get my exhaust fitted today the car suddenly started to make a loud noise when accelerating. It sounds like a mixture between a belt slipping and jingling keys. The sound is coming through the vents, and with the window down, it is very easily drowning out the sound from the exhaust (to give you an idea of how loud it is). The sound comes and goes depending on throttle position (not RPM). I can use the entire rev range without any noise, as long as i use less than 15-20% of the throttle. Any more than 20% throttle and the noise starts, regardless of RPM or speed. More throttle = sound much louder.

Any ideas?

EDIT: forgot to say, belts were changed less than 1k miles ago

alexisonfire · 2 Feb 2011 at 19:35

Bit more info after driving it again. It doesn't do it below 3k RPM, and the sound gets higher pitched the higher the RPM which would suggest what ever is making the sound, is getting faster, hence higher pitched. Sound is barely noticeable when reving the car stationary aswell. Heres a quick video i just did.

http://www.msphotography.net/private/IMG_0859.MOV

RSClio · 2 Feb 2011 at 19:39

Ouchhhh! Is that with the new exhaust fitted too?? Sounds exhaust related to me, like something has come loose inside.

Janesy B · 2 Feb 2011 at 19:40

Sounds like the exhaust, I take it you took it easy to let the exhaust paste seal up? Maybe sounds quieter when stationary as the engine isn't under load. You get similar symptoms with a leaky exhaust manifold - not so loud when standing still but when under load you get a pronounced tick tick tick noise.

alexisonfire · 2 Feb 2011 at 19:42

This started PRE new exhaust

RSClio · 2 Feb 2011 at 19:43

Was it a full system? Did you ask the garage what they thought?

Biohazard · 2 Feb 2011 at 19:43

a lot of exhaust sealants these days cure with the heat anyway JB

that does sound a bit farty to me though

alexisonfire said:
This started PRE new exhaust

was the cat replaced?

Janesy B · 2 Feb 2011 at 19:46

Biohazard said:
a lot of exhaust sealants these days cure with the heat anyway JB

that does sound a bit farty to me though

was the cat replaced?

He's fitted a non-silenced decat pipe as well IIRC.

alexisonfire · 2 Feb 2011 at 19:47

RSClio said:
Was it a full system? Did you ask the garage what they thought?

Cat back, i didn't get the decat fitted today because the spring bolts that hold on the cat were looking a bit worse for wear, so he didn't want to damage them and not be able to put the decat or cat back on. Completely skipped my mind to ask him what he thought, excitement blindness

Biohazard · 2 Feb 2011 at 20:04

Janesy B said:
He's fitted a non-silenced decat pipe as well IIRC.

hmmm

what make of exhaust?

Biohazard · 2 Feb 2011 at 20:05

alexisonfire said:
Cat back, i didn't get the decat fitted today because the spring bolts that hold on the cat were looking a bit worse for wear, so he didn't want to damage them and not be able to put the decat or cat back on. Completely skipped my mind to ask him what he thought, excitement blindness

If that is the case then I would be inclined to say partially collapsed cat mesh.

Get the decat on see if it goes, if it doesn't its related to the rotating mass. Ie the engine. (what prize do I get?

)

alexisonfire · 2 Feb 2011 at 20:08

Biohazard said:
If that is the case then I would be inclined to say partially collapsed cat mesh.

Get the decat on see if it goes, if it doesn't its related to the rotating mass. Ie the engine. (what prize do I get? )

I have just been reading loads of different car forums and other people with a problem with the EXACT same description have had collapsed/clogged cats. Replacing the cat made the sound go away. I think it has got louder since i got the new exhaust on, although its hard to say.

Biohazard · 2 Feb 2011 at 20:28

alexisonfire said:
I have just been reading loads of different car forums and other people with a problem with the EXACT same description have had collapsed/clogged cats. Replacing the cat made the sound go away. I think it has got louder since i got the new exhaust on, although its hard to say.

That would make sense.

Try decat. Fingers crossed it fixes it.

melchy · 2 Feb 2011 at 20:49

Possibly joint between manifold to cat leaking, especially if the bolts are looking a bit past it. Mine failed completely (broke the bolts as they were badly corroded) and the car sounded like a jet while i limped to the garage.

Biohazard · 2 Feb 2011 at 21:18

melchy said:
Possibly joint between manifold to cat leaking, especially if the bolts are looking a bit past it. Mine failed completely (broke the bolts as they were badly corroded) and the car sounded like a jet while i limped to the garage.

You would hear that at idle

alexisonfire · 2 Feb 2011 at 21:36

Would the car of passed its MOT last week if the cat had failed like presumed?

D-an-W · 2 Feb 2011 at 21:48

You said the belts were done recently, did it make this noise before that?

alexisonfire · 2 Feb 2011 at 22:00

D-an-W said:
You said the belts were done recently, did it make this noise before that?

I've only owned the car since Sunday, and the noise has only started today.

RSClio · 2 Feb 2011 at 22:45

alexisonfire said:
Would the car of passed its MOT last week if the cat had failed like presumed?

If the noise has just appeared today, it sounds like it has failed today, so may well have being fine MOT time.

Deffo not the belts! Well IMO sounds very much like the exhaust. If and a bif if the belts were done by a none specialist and are out, well be very very careful and get it checked tomorrow asap as it can and will take the engine with it.

BennyC · 3 Feb 2011 at 08:51

For the brief air filter discussion above a test was done by a certain magazine, can't remember which, and the article is on CS (engine & exhausts subsection). They tested a few different filters, put each one on a RR and found that the difference was minimal and quite often resulted in a power/torque drop due to the standard airbox being already well designed. Spend the cash on brakes instead