Weird Shutter at 3-4k rpm when floored

[Sql_RS4]

Very recently my car has developed a VIOLENT shutter under high load over as near as makes no difference 4k rpm. In all other throttle positions the car runs fine no matter the rpm. MAF says 270g/s according to the vag. The cylinder voltages are all over the map from 9 to 12 or 17 i dont remember. Any ideas what the problem could be?

No warning lights or any other symptoms. Wish i could describe the feel of the drive better. The run starts fine then over 4k when the boost is at the max it gets ugly. It is not subtle it is not hard to notice it is an in your face violent non regular vibration and it last until you take your foot off the gas. Car also feels noticeably slower, like it was in limp mode.

Any ideas guys?

[Nige_RS4]

Maybe an EGT probe down or your spark plugs need changing? Do you get any errors with vag-com i.e. mis-fires?

[Sql_RS4]

No errors but I came to conclusion with my mechanic that it might be a faulty spark plug or spark plug coil.

We will try to find which one it is and we will see.

When I had EGT sensor down it just limped a lot and got back to normal after quick restart but did not shutter at all so I think it is not EGT this time.

I changed oil and all filters today and found out that fuel filter might have not been ever changed as it got extremely rusty - my mechanic could not unscrew it - will have to book like 2 hours with him next week to sort it out as he might need to cut it off. I heard Audi placed it in weird and complicated spot and that you need to get fuel tank down a bit to replace filter...

Anyway I do not think it was caused by clogged filter but we will check that as well.

[Blue_Thunder]

Would a faulty spark or coil not make the engine shudder all the time?

[Nige_RS4]

Is your car std, as I thought even standard RS4's went above 300g/s?

[carlosfandango]

I have had the same problem, changed plugs, serviced changed the exhaust sensors and was still the same, at first I did not have any errors on VAG but then it showed a missfire on 4 so we changed the coil pack and that has made a big difference. The car is still not 100% right so I think I need to change all the coil packs. I also have been wondering about the Fuel filter.

[jimbo1234567]

itll be the maf. dodgy dave had the same problem a long time ago. just try disconnecting the maf plug and going for a run, it wont harm it. also have a read here

http://www.rs246.com/index.php?name=PNp ... highlight=

[AndyC1982]

Hi there

I have been having the exact same problems, I thought it was the coil pack so i changed that out but i still have the same issue, i have came to the same conclusion as Nige, it is the probe down to the spark plug. I have just recieved it from audi and i'm changing it out this weekend so i'll update you if it helps

Regards

Andy

[AndyC1982]

itll be the maf. dodgy dave had the same problem a long time ago. just try disconnecting the maf plug and going for a run, it wont harm it. also have a read here

http://www.rs246.com/index.php?name=PNp ... highlight=

I changed out the MAF as initially i thought the same as Jimbo but your issue sounds alot like mine, i would change out the plugs it should be obvious which one has the issue, then change that coil pack and probey thingy (sorry to get all technical!!! LOL)