HI All, Can you help? My faithful and reliable twenty year old A4 2.0 TDI has developed a few issues. Lack of power in cruise mode going up hills and major juddering when I am lead footed (not often, but when i need to get out of trouble) which causes the engine to vibrate and judder. The car has full Audi servicing for the first 16 years of its life and more recently local garages in the last fours years and has 126,000 miles on the clock. ( i bought it for long distance driving but was made redundant soon after hence the low mileage.)

I asked Chat GPT for some clues and it said most likely faults were MAF Sensor, EGR Valve, Fuel Filter, Boost Hose Leak and that very common issues with this engine were Tired MAF sensors, EGR carbon build up, Split intercooler hoses, Vacuum Hose deterioration. I took it back to my local Audi dealership who at first found nothing so I told them to T drive it and sure enough they found the car drove as I explained above.

They said they found 'A Vacuum leak at inlet manifold flap actuator, require new actuator, then test after, however there maybe a possible fuel issue."

I also have a large squeaking noise from alternator and they said change the belt and maybe its the alternator pulley clutch seizing so they recommend new pulley and new belt. They said all that work would cost me £3,000 but even then, they could not guarantee to resolve the issue and it may require further work to rectify matters at further cost. The car is book price at around £900 so what to do?? Audi were good enough to give me all the parts serial numbers to deal with those tasks but do you think I should ditch the car or would a local garage be capable of dealing with these issues? I have looked at local VW/Audi credited smaller garages but the feedback on those is indifferent, so your feedback would help. The car goes like stink otherwise, having made two trips to Cornwall and back in March and still returns 50 mpg and looks great.

Your thoughts most welcome, many thanks.

If the Audi dealer found no faults at the first diagnosis how much reliance can you place on his second attempt? Then there is AI which has given you a list of possible faults, but no certainties. Are you going to spend money on that basis?

I suggest you find an independent VAG specialist who can test the car with a decent code reader such as VCDS, and let him do the diagnosis before committing to any expenditure.

Main Audi dealer will be minimum £200 per hour for a technician, not a mechanic. As suggested, find a trusted independent and expect to pay for health report. A 16 year old car, if serviced properly can still be kept on the road, however, except you'll need to budget for some of the repairs. You don't need to do everything at once. What's critical? And what's worth doing, say in 6 months.

Thanks Gents, sometimes you cant see the wood for the trees, but your feedback is valuable thank you.

Do please let us know the outcome.

Thank you, I will do. Based on the advice above I have now booked the car into a local VAG garage with VCDS code readers (as mentioned above) for next Thursday. I emailed them and the garage rang me two hours later for a chat and to confirm a 9 am appointment.

Any update for us Wayne?