Megane Cat Rattle

macroman

I'm driving a 99 1.4 Megane RXI (new shape) and just after Christmas it developed a rattle or what seemed to be a blowing exhaust. Sitting in traffic I noticed a rattle on idle which dispersed when I released the cluth and accelerated a kind of a louder rattle/knock from the exhaust appeared.

I've concluded that it could be the heat shield or the cat itself (~€250 for a replacement). Anyone had any similar experiences with Meganes/Clios/Scenics? What turned out to be the problem/cost?

As an aside - the back box of the exhaust was replaced before I bought it about a month ago, so I'm thinking that maybe it was misaligned and is knocking against the rear suspension arm but from sitting in the cab the noise is coming from what appears to be right underneath me.

YraggarY

I had a similar problem with my exhaust on my Toyota Sera; developed a rattle at the backbox over Christmas. I brought it to a garage and they welded a loose section of piping back together near the backbox, but after 5 minutes of driving the sound came back.
The loose piping wasn't actually the problem. One of the rubbers that holds the exhaust to the car was overstretched, and the exhaust was hanging down and rattling off various parts of the underbody. If your problem turns out to be similar, you can just cable-tie it back up as a temporary fix.
Jack your car up onto axle stands, and have a poke around the back of the exhaust. If you're not comfortable doing it yourself, make sure you get your mechanic to check the rubbers before he starts removing or replacing parts. The garage I went to should have noticed it but didn't. Perhaps they would have if I'd mentioned it to them, so maybe just tell them you think one of the rubbers might be gone, and ensure they check all that out first. This should cost very little to replace!

macroman

I've lifts in work I can use after hours so will have a poke around when I get a chance. I did notice that the cat is hanging down about 4 inches when I had a quick look under it tonight in the dark so it could be that rattling. Just praying it isn't the cat itself which needs replacing.

Frankie Lee

9 times out of 10 on them it is a heat shield hitting off the exhaust which can be easily pulled back.

macroman

Could be it as there is no rattle when making a hill-start only when on level ground firstly when idle there is a small rattle but when moving off it becomes more of a bangie rattle.

Frankie Lee

Well hopefully for your sake, the heat shields tend to make a terrible racket altogether.

Big Nasty

Frankie Lee wrote: »

Well hopefully for your sake, the heat shields tend to make a terrible racket altogether.

Failing that it will be the Death Rattle!

bostoncommon

look under the car and you will be able to see it just bend it back/

John mac

Frankie Lee wrote: »

9 times out of 10 on them it is a heat shield hitting off the exhaust which can be easily pulled back.

yep i would concur, i had a 00 one and it used to happen occasionally ,

slight tweek of heatshield cured it ,

also check the rubbers while you are at it.

kasper

as in your first post you say the back box is not lined up properly and knocking against something if this is the case the whole exhaust system will be stressed and strained causing the rattle up front ,ideally if you put car on ramps loosen all connections and work from the front to the back it migt fix all your poblems