A6 Very Sluggish after 80mph

**anilpm** · 11-03-2011,01:57 PM

Hi All,

I have an '05 plate A6 2.0 TDI. It recently had a few problems, where the car juddered between 1,800 and 2,200 revs. This has now been fixed by having the Intercooler Radiator replaced along with the Turbo House.

However, when am on the Motorway as soon as I hit about 80mph, the car becomes very sluggish and struggles to take fuel. This will carry on even if I slow down and try to gain speed. Even if floored the accelerator, the car would not response as excepted. I would then need to stop, switch off the engine for a few minutes for it to become back to normal. But soon as I hit 80 mph again, the same problem happens.

Any idea on what could be wrong?

Thanks,

**Crasher** · 11-03-2011,02:03 PM

You need a fault code read but I have had quite a few of those with turbo fault codes (doing what yours is) due to a broken wire to the turbo N75 control valve.

**joshA6** · 14-03-2011,04:39 PM

Originally Posted by anilpm

Hi All,

I have an '05 plate A6 2.0 TDI. It recently had a few problems, where the car juddered between 1,800 and 2,200 revs. This has now been fixed by having the Intercooler Radiator replaced along with the Turbo House.

However, when am on the Motorway as soon as I hit about 80mph, the car becomes very sluggish and struggles to take fuel. This will carry on even if I slow down and try to gain speed. Even if floored the accelerator, the car would not response as excepted. I would then need to stop, switch off the engine for a few minutes for it to become back to normal. But soon as I hit 80 mph again, the same problem happens.

Any idea on what could be wrong?

Thanks,

With your shuddering problem, can you confirm that the answer was a new intercooler (as far as i know there is no separate radiator for this) ANDa new turbo hose? I am having the same problem but not all the time.

YOur new problem seems to be your car going into limp mode to protect the enigne. This is usually becaus eit is overboosting. As per the other post, you need to get it check on diagnostic tools as it sounds like the solenoid valve or turbo.

**anilpm** · 18-03-2011,12:39 AM

Originally Posted by joshA6

With your shuddering problem, can you confirm that the answer was a new intercooler (as far as i know there is no separate radiator for this) ANDa new turbo hose? I am having the same problem but not all the time.

YOur new problem seems to be your car going into limp mode to protect the enigne. This is usually becaus eit is overboosting. As per the other post, you need to get it check on diagnostic tools as it sounds like the solenoid valve or turbo.

Hi,

Sorry for the late reply. I took it to an Audi Specialist in Leicester and they checked it out with the diagnostic software and it came with the fault being an air leak. I then booked in for further investigation. They found the Intercooler to be damaged most likely from a car crash, (previous owner), where the body work repair was carried out, but the Intercooler was not replaced or fixed. I bought the car in Feb '10 and it kept happening intermittently until Jan '11 when it just got worse and never went away. The Turbo Hose was damaged and had a large rip in it (hence the Air Leak), so that is why that part got replaced. Am a novice when it comes to technical stuff with cars, but the way the Specialist explained things, I gathered the damage to the Turbo Hose was because of the damage caused to the Intercooler. I think I had the problem all along and it got worse over a year. The Specialist also showed me both the damaged parts.

I had the Cambelt replaced a month before at the Main Audi dealer, am not sure if they would have noticed, but if they should have noticed then am surprised they did not tell me that the Intercooler and Turbo was damaged.