Put this to bed!!!

[matt the cat]

The 4 k rattle: I understand that the culprit seems to be exhaust related...now is it that the resonant frequency from the exhaust at approx 4k causes vibration elsewhere(my intermittant noise seems to come from within the dash) or is it something working loose within the exhaust system?

Please bear with me, I,m an engineer and would like to understand the specifics rather thatn just let reno give my some rubbish, or just buy a new system.

If it is down to resonance then there are things that can be done the counter them....

Cheers

 

[KDF]

Something working loose within the exhaust system normally like a baffle. and rattling at 4k

 

[Viv172]

I was told by my dealer that it was loose bafflers in the mid section of the exhaust...a snip at £500 to replace by Renault.

 

[DARKO]

Mines just devloped the 4k rattle after 18k miles.

The fact that it only occurs at 4k would lead me to believe that it is the resonant frequency of a heat shield harmonizing with the exhaust at that point. As to curing it... Alter the shape, mass or material?

Has anyone actually asked renault to explain the particulars about it? Bet that would be an interesting story!

 

[McBunny]

its is the baffle in the centersection working loose nowt to do with anything else at all

 

[DARKO]

Thats sorted that then!

 

[Daipac]

This happened on my old 97 Clio 1.4 Sport and I was told it was the heatshield rubbing against the exhaust ! Unbelievably it still happens on my 02 172 which is going in to get this fixed on Monday under warranty.

 

[Smokey McPot]

While were on the subject, I could do with some advice....

My Cup is coming up for 10,000 miles, its a March 03er....and thus is soon to be due for a service, but I havent seemed to developed the dreaded 4k rattle.

When it goes in for the service is it something that will be looked at by default or will i need to tell them to check it out?

Also is the problem covered by warranty, seeing as its a known fault?

 

[Daipac]

Smokey, it is covered by warranty yes. I am not sure you can ask them to investigate a fault that is not there YET ! You could ask then to check to see if anything is being worked loose and looks like it could cause a problem. Whether they will do that is another thing.

 

[McBunny]

its coverd by warranty but only in first year

they cant look for it as they wont find it as its nothing you can see and only usually happens when very warm

ps its 4k rpm not 4k miles

when you have it trust me you will know about it

 

[Daipac]

It is only covered in the first year but many people on here have had the same problem and had it changed under warranty in the second and third years havent they ?

 

[Smokey McPot]

Ahhh, makes a bit more sense, seemed odd that everyones car would develope the prob at 4k miles! i test it later on me way home from work just in case.

Cheers for ya help peeps.