Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2006 Audi A4 owners, lightly cleaned up (personal details are redacted by NHTSA).
Tl contact owns a 2006 Audi A4. While driving 35 MPH, the contact noticed smoke coming from the front and back of the vehicle. She pulled the vehicle over and turned off the ignition. She then heard a loud explosion underneath the vehicle. She exited and noticed flames underneath the vehicle and from under the hood as well. When the fire department arrived, the front half of the vehicle was completely engulfed in flames. The fire was extinguished, but the fire department was unable to determine the cause of the failure. A fire report was filed. The contact did not notice any failures prior to the fire. The vehicle was inspected by an insurance adjuster, who was also unable to determine the cause of the failure. The vehicle was labeled as destroyed. The contact is in the process of notifying the manufacturer. The failure mileage was 33,000.
Tl* the contact owns a 2006 Audi A4. The contact stated that there was a sweet, burning smell present in the vehicle for two years. The vehicle was taken to the dealer several times and the contact was always advised that nothing was wrong with the vehicle. The radiator failed at one point and the vehicle was taken to a local mechanic. The contact was advised by the mechanic that a plastic piece of the radiator had fractured on and allowed anti -freeze to leak into the vehicle, causing the sweet, burning odor. The vehicle was repaired. The VIN was not available. The failure mileage was 89,000 and the current mileage was 104,000.
Tl* the contact owns a 2006 Audi A4. While driving 40 MPH, the vehicle stalled. The contact was unable to restart the vehicle. The vehicle was towed to an independent mechanic to be diagnosed. The failure was diagnosed as a failed fuel pump, a worn intake camshaft, and a faulty camshaft follower. The vehicle was repaired, but the failure recurred. The manufacturer was notified of the failure. The failure mileage was 140,000.
Car did not show any signs prior to check engine light coming on. Within several minutes of check in light appearing the car begin driving rough and smoke poured from under the hood. My husband quickly cut the wires of the coil pack from the housing to prevent the fire from spreading, as I grabbed the fire extinguisher.
In October 2006, purchased a new 2006 Audi A4 from carousel Audi in golden valley, mn. The car was well maintained and has less than 62,000 miles today. In late summer of 2013, I began noticing that the car jerked heavily when putting it into reverse from a parked position. The car has an automatic transmission and I then began noticing the car not accelerating properly and laboring when nearing 50 MPH on the highway. The motor would rev up and make an unusual sound and it was too dangerous to drive on the highway. I brought the car to the Audi dealer and they advised me that the transmission and computer module were not communicating properly and that it needs a new module at a cost of about $3800. They refused to pay for any of the repairs. …
I have the A4 w/ 3.1 liter v6. Almost immediately after purchase, transmission exhibited bumpy lurching start from stop. Audi diagnose said that's symptomatic of this transmission and engine combination. Nothing could be done to prevent. Within 1st year, the car would stall and completely shut down, necessitating a re-start. Sometimes upon start, and most notably (and the example cited above) when driving at slow speed. (I suspect the stall problems described relates to the lurching transmission problem). On this incident there was no check engine light. Took to Audi, they couldn't identify problem. I took to an independent -- they determined problem as fuel pump. Replaced fuel pump. Most recently the car stalled when initiating a left turn from a slow 10-15 MPH roll. …
Audi issued a technical service bulletin that I found on your website. This bulletin was regarding the exact parts the dealer (Audi) identified as being affected on my car (high pressure fuel pump, cam follower, and corresponding intake camshaft cam lobe). This bulletin (not a recall, but distributed internally to dealerships) clearly states that this is a widespread issue that affected all VIN ranges of specified Audi models from 2005-2007 that included mine. Audi extended drivetrain coverage on these vehicles to 10yr/120K mi. This issue causes a worsening loss of power upon accelerating (making driving at all speeds dangerous) and eventual engine failure if left alone. I am the 3rd owner of this car, so I did not receive the intended letter from Audi stating the specifics of this coverage extension. My vehicle is currently at ~110K miles at the time of this service (~4-5 days ago). …
Audi A4, 2006 convertible : after driving the car 12 miles in stop and go traffic on a 2 lane street I noticed smoke coming from under the hood, not a lot. No warning lights on the dash. Temp outside was 75. So I drove another 2 miles, then I saw a lot of smoke coming from under the hood - I turned on the turn signal to get into the other lane and then the coolant low sign came on the dash. Then a lot more smoke. After letting the car cool in a parking lot, I added the coolant/water mix as called for in the service book ( had the staff at oreilly auto parts look up the correct coolant). As soon as I started the engine all the coolant ran out. I called the tow company to tow the car to the service station. It appears to be a cracked valve. Also 3 radiator hoses all need to be replaced. The car just had a full tune up 2 months earlier.
My 2006 Audi A4 just died on the road the day after I did the 95K services.. Couldn't start up the car after many attempts and finally when I could, it was very loud and shaky.. Got some smells from the front also but I couldn't figure out what was wrong. I sent it back to the dealer right away and going through some diagnosis, we need to replace the engine because the crankshaft inside the engine's got broken sleeves. Prior to this, there were recalls on my car, my service light was on for a while and it was linked to the recall, they replaced the breather, but did not have to replace the turbo pipe.. When my car died on the road, I was lucky that just turning out from dunkin donuts for an very early morning coffee (5 am), because it was so early, there weren't many cars, otherwise there would very likely be a crash.
When I drive my car with the headlights on one randomly turns off and then I get a display in the dash that's says "left headlight dipped" this also happens to the right side. I have to turn the knob kn the dashboard on the off position and turn them back on the on position and they start working again. This is ridiculous and unsafe. Please help. Also my engine is burning oil very fast I just had an oil change and drove the car for 80 miles and the dip stick already shows half way full. I had the head gasket and vacuum pump gasket replaced but it still hasn't fixed the problem.
Engine complaints in other A4 years
Frequently asked questions
How common are engine problems on the 2006 Audi A4?
NHTSA has 21 complaints about the engine & cooling of the 2006 Audi A4, 7% of the model year's 295 complaints. The component named most often is engine (2 mentions).
Is there a recall for 2006 Audi A4 engine problems?
No. NHTSA lists no engine & cooling recall for the 2006 Audi A4, though it has 3 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2006 Audi A4 engine problems start?
Half of the complaints with a recorded mileage happened before about 89,000 miles, and 6% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 3 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.