Dreadded 16618 overboost code!!!!

[2006audirs4]

Hey ya"ll
Reletivly new to this forum stuff so please bear with me

My wifes a3 has just brought this code up on vagcom, its a little high on the miles at 120k and is the 2.0tdi 140 model.

Drove thw qcar myself and occasionally goes into limp mode, but also sometimes it seems as theres no boost at all from the turbo.
However but if i drive it hard the turbo boosts fully in all gears. Also the turbo sounds more like a supercharger when its boosting.

AND just today it seems to be smoking abit thro 1st and 2nd (blue smoke)

So... Do i need a new turbo? Or am i missing something here, looked thro loads of differnt forums but still cant seem to find a solid answer.

Please help!!!!

Thanks marc

 

[jonnysimm]

i had the same problem and i had to replace my turbo it might not be the same for you but just letting you know. its very common on these cars i know quite a few ppl whos turbos go pop.

 

[mike foster]

Reconditioned turbo at that mileage. Should be able to get one fitted for about £700. Don't bother getting it cleaned as it will happen again.

Don't drive the car over 2000 rpm because if the turbo does blow you'll need a new engine !

 

[tdi-man]

I have a turbo for sale in the classifieds

i had it recon 2 years ago.

inbox me for more details
ia also on ebay

 

[2006audirs4]

Thankyou all for your quick replies, just got back this minute from my local audi specialist and he says the actuator on the turbo is moving freely so the turbo is fine.
He said its probably all down to the N75 Valve, does this sound right?

Thankyoooo

 

[tdi-man]

He said its probably all down to the N75 Valve ????
well if you buy a new one and it still does it it will probably not be that


Also the turbo sounds more like a supercharger when its boosting - I WOULD SAY TURBO FAULTY

on that milage i would say Turbo

 

[2006audirs4]

Well yeah, but Thats what i thought too and he supposed to know what hes doing!
Well thankyou tdi man
Ill start with the cheap option of that n75, if not ill be inboxing you for a price on that turbo.

 

[tdi-man]

i thought n75 will cause underboost ???

there not cheap to buy.

 

[tdi-man]

FOUND THIS FOR YOU

AUDI A3 2.0 TDI 2005 BOOST CONTROL VALVE DIFFERENTIAL UNIT PA66 PA61/6T GF50 | eBay

 

[tdi-man]

[h=4]Possible Solutions[/h]

• Check Charge Pressure Control System
  • Perform Output Test (to check the Turbo Charger)
  • Perform Basic Setting (to check the Charge Pressure Control)
  • Perform Pressure Test to locate Leaks
• Check/Replace Boost Pressure Control Valve (N75)
• Check/Replace Boost Pressure Sensor (G13)
• Check/Replace Turbo Charger

 

[mike foster]

I agree with tdi-man. With the symptoms you describe your turbo is at (or very near) the end.

It's your choice mate but whatever you do go steady until it's fixed !!

 

[2006audirs4]

Thanks again for all your rapid responses!
Tdi man... You are the man!
Will keep you all posted as im checking everything this week