help with an irritating rattle somewhere outside the car.

[Charlie Farley]

Well after a couple of weeks after getting the old wagon back all seemed to be going well and problem free until now, well since it came back i think.
There now appears to be a really irritating , and i do mean really irritating, low frequency rattle somewhere outside the car.
had a good look around and nothing seems to be loose , but from previous experience with rattles on my old subaru legacy they were the heatsheilds under the car and around the exhuast, and were a real pain to stop rattling.

The sound i can hear is at low rpm and has a deffinate metallic twang to it, prob between 1500 to 2000 rpm , nothing under load , but allway when the throttle is backed off between gearchanges, i can hear this short twangy/rattle but as soon as rpm increase nothing.
To be honest its doing my head now, any thoughts on a possible starting point to look at, are there any sheild that are known to be problematic etc or is it something more sinister.
any help would be great, i dont mind crawling around underneath but a more closer start point would be ideal.

rob

 

[joinerman]

Could be the CAT starting to break up internally

 

[SDHA4SLine]

Total guess on exhaust side of things but there are (apparently) weights that are attached to the exhaust somewhere, maybe one has worked lose.

I only know about these as audi told me mine were missing on the last on last health check but said don't worry about them being missing.

 

[Charlie Farley]

its really odd, there were no odd noises before it went into dealers for all the work to be done, seems to be since it visited audi.

 

[Gav:in]

What was it in the dealers for?

 

[SDHA4SLine]

What was it in the dealers for?

Everything

 

[Gav:in]

Everything

Haha ah I see.

 

[Charlie Farley]

Everything

Too right, went in for everything and still came back with something else, starting to loose interest with it again, RS4 still ticking away in the back of my greycells.

 

[SDHA4SLine]

With the seriousness of the work you've had done I would get that car back down the dealers just in case an innocent (yet irritating) rattle could be more serious problem lurking.

 

[Charlie Farley]

In all seriousness , if i have take it back again for anything else now , it will be staying there for good, and i'll get a full refund and put it towards something else, just dont need the continual hassle from this car.

 

[gary_a4_quattro]

there are (apparently) weights that are attached to the exhaust somewhere, maybe one has worked lose.

Any idea what the weights are for, did the stealers offer any suggestion ? Sounds like a mad thing to do Audi !?!

 

[Charlie Farley]

i'm starting to think its something else now, the wife was in the car today and could hear it, she didnt think it was a metalic sound , more of an escaping air sound or air being forced out from a pipe.
That made think , could it be the turbo bypass valve or a pipe leak in that area, after listening to it closer, is does sound very similar to a dump valve going off briefly, when the revs drop off.

 

[Joe_Murphy21187]

Did you ever get to the bottom of this Rob? I've developed a similar metallic sort of rattle at low speeds only and don't know what it is!

Be interested to know if you ever identified the cause... Thanks!

 

[Charlie Farley]

yep most certainly did, turned out to be an issue with the turbo and had to have a complete turbo kit inc a load of other parts to go with it, found out it wasnt covered by the warranty so was not a happy bunny, when i had a moan at audi about it they agreed to cover the whole repair parts and labour, been fine ever since.

 

[NotNormal]

Check you door handles

Tom

 

[Charlie Farley]

yep, that was the first thing i did, but it wasnt that sort of noise to be honest and had a deffo connection to engine speed as opposed to forward motion speed etc, anyway found it in the end.
mind you, my avant does appear to suffer from that dreaded drivers side door handle cover rattle, i keep tightening it up using the credit card trick but its starting to get loose again after 2-3 months.

 

[Joe_Murphy21187]

That's slightly worrying... Don't want to fork out for a new turbo but the car is 8 years old and nearly on 150k, so definitely won't be covered under warranty.

What was actually wrong with the turbo? What else did you need to replace?

Thanks for the reply btw!

 

[Charlie Farley]

It was a strange thing really as the car had been in for a completely new steering rack and i'd only had it back a day when the noise started and audi said they had run a diag on the car after the work they had done and all was fine.
I will dig out the file and see what the details were for the repair and let you know.
rob