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MG MGF Technical - Engine/exhaust noise

Guys, any ideas about this on a 1996 VVC.
I'm getting a noise from the engine exhaust area. It is a high pitched rattle almost whistling noise, it only occurs at maximum throttle, under acceleration at over about 4k RPM. If you back off a touch and hold steady high revs it goes, but then comes back if floored again. I'm thinking its like something resonating and vibrating when the engine moves under max power. Could it be the Exhaust Flexi pipe, what do they sound like when they have gone ?
Thanks in advance.
Stuart

My flexipipe has gone on my F, haven't replaced it yet. The only noise it makes is a rattle when the engine and weather is cold. As soon as the exhaust heats up it stops. It really is in the early stages of failing though, so if yours is a bit further gone than mine it'll most probably be a lot noiser.

If you get under the car (can just be done without jacking it up) have a look at the flexipipe.

http://www.apttony.co.uk/Servicing/FlexiPipe.html

Emma (Green with Envy ~ S369 FAR)
Emma Jackman

I'm not quite sure when the flexi pipe 'goes' but the webbingg around mine had disintergrated so i've cut it all off. I still get a vibration (sounds like a rattle snake) at 2250 rpm. Once i accelarate past that (or decelerate past) she's fine. I was going to pop to Halfrauds to see if i could find something i could jubilee clip over it to muffle it somewhat until i can afford a new stainless jobbie.

Martin

the flexipipe is made like aly ducting, it is a continious snake of interlocking metal, as such it can flex a little, but it cannot be succesfully clamped over with a jubalie clip - you will either crush it at the split or the clips will be shaken off the split.
Will Munns

It is the engine showing it's appreciation!
Charles

It does run well and revs happily, its just not a pretty sound !!
Stuart

Exhaust manifold leak? I had something similar, and it turned out that one of the exhaust studs had worked its way loose, allowing gas to escape past the gasket. Noticed a drop in power too.
Rob Bell

Doesn't really sound like something blowing, more of a high speed rattle / something vibrating ! I guess it doesn't have to be the exhaust it was just a thought !
Stuart

I think that an inspection of the engine bay is called for. My car suffered a rattle a few years back - it turned out that the remote oil filler neck had separated from the inlet manifold. I don't think that this is a common problem, but if there is something loose, it can be easy and cheap to fix.

Thereafter, you need to determine whether the noise is coming from the engine or not. Which would be a little more worrying - especially for the wallet. :o(
Rob Bell

Check the heat sheild on the CAT they can rust loose and rattle like a goodun.
Steve Ratledge

Stuart, Rob Bell could be right.I had a similar
problem with Exhaust Companies checking out my
exhaust, could find nothing wrong. Then, I opened
the boot, started the engine and looked. Immediately
notice the oil-filler neck was vibrating like crazy
and very simple to fix. Hope this is your problem
rather than the exhaust.

Bill Prearson
W.A. Pearson

Thanks Guys i'll go and have a look at the above
Stuart

Hi Stuart,
I have just had the same problem with my 1999 VVC in that a high pitched noise developed when revved. In the end I took it to a garage and at one piont there was 4 of us trying to detect where the noise was coming from.
Each of us decided that it was the flexy exhaust but still uncertain.
I paid £144 to have it replaced and guess what....the noise has gone, yeepee!! Now revs like a good-un.
I agree with Rob, get it checked out on ramps and hopefully it will be the inexpensive flexy pipe. Good luck. Paul..
Blackers62

Guys, thanks for all the above. Having stood at the back of the car and revved it using the throttle body it seems that the noise is coming from the exhaust, but only one of the pipes !! In view of that I guess its a small hole or a slightly loose baffle on that side that whistles when under full throttle. This is slightly less worrying than having been told it was a sticky valve by my local garage !
Thanks again, helpful to know you're out there !
Stuart

stop trshing the tits out of it!
sam

What's the point in having a vvc and not ?!?! Anyway on a serious note, is the VVC back box the same as the non vvc. and does anyone know where I can get a used one in the Essex/Herts/East London areas, a breaker who does MGF's etc ?
Stuart

There's a breaker in Essex that has a few F's in - chat to the guys in 'Essex Roadsters' - they'll pass on the contact details :o)
Rob Bell

This thread was discussed between 08/06/2006 and 19/06/2006

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