Noise on boost. 1.8t bex quattro

[tom2]

Hi,

I was driving on country lanes this afternoon and had my window down. I noticed that when the boost comes in there is a high frequency fluttering kind of noise (hard to explain) it sounds like air not a mechanical noise.

Ive noticed too that it no longer pulls hard until around 5krpm, no smoke from exhaust and oil is only 800miles old.

any thoughts?

thanks

 

[madmike01uk]

If the flutter is when you lift off the throttle then it will be turbo flutter due to the dump valve possibly being faulty.

 

[B-J-P]

Maybe pinking, would look at maf and spark plugs. What fuel Are you running it on?

 

[tom2]

Only happens when accelerating hard, I usually run it on shell optimax as I have a fuel card from work, I did fill up on the cheapo tesco stuff when I got called out for work at 2am on Sunday, but it was an emergency so didn't have a choice really.

 

[B-J-P]

I had similar issue, put super unleaded in and it's fine now. Strange as I didn't think it would make that much difference. Might be something that simple, I'd Put some more optimax in and see if it cures it.

 

[madmike01uk]

you should here a whistle when on boost with the window down. I'd check for fault codes and boost leaks if I were you.

 

[Dobermansteve]

I hate tesco fuel! used it once in my old civic and im sure it was the cause for my EML coming on because I got the code cleared, filled up elsewhere and the light never reappeared!

 

[A4sportMrT]

Could be faulty diverter valve, my mates octavia vrs did the same when booting it, he changed it to a forge recirc and fine now

 

[tom2]

Turned out to be a tiny split in a hose

All sorted now,

A lad at work told me to take it round to his dads, I turned up and a doddery old guy hobbled down the drive and it turns out he is a retired rally car mech and worked on the original 1980 quattro rally car, spent 3 hours looking at all his old photos etc then he started the car and got me to rev it while he listened, and within 5 seconds knew exactly what and where it was !! That was this morning and I'm still amazed, I ain't paying audis college drop outs another penny after seeing him !

 

[B-J-P]

Glad you got it sorted, just out of interest which hose was it?