This bulletin contains instructions for using the UV additive to find engine oil leaks.
full bulletin at NHTSA ↗2005 Audi S4 engine problems
moderate 4 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Complaints
4
Recalls
0
Avg fix
$3,100
When does it fail?
Of the 4 engine complaints filed for the 2005 Audi S4, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
No new NHTSA engine complaint has been filed on this vehicle in over 8 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This bulletin contains instructions for identifying and mixing factory fill coolants.
full bulletin at NHTSA ↗This informational bulletin contains all the the Audi Oil Quality Standards that should be used when doing an oil change.
full bulletin at NHTSA ↗Supersedes Technical Service Bulletin Group 19 number 15-61 dated July 7, 2015. Discontinuation and mixing of Audi-approved engine coolants. G11, G12, and G12+ coolants have been replaced by an improved version. G12++ coolant (for service available) has been introduced in MY 2005 for all engines. G13 has been introduced in MY 2008 as factory filling and service.
full bulletin at NHTSA ↗Supersedes Technical Service Bulletin Group 19 number 14-50 dated June 20, 2014. Discontinuation and mixing of Audi-approved engine coolants. G11, G12, and G12+ coolants have been replaced by an improved version. G12++ coolant (for service available) has been introduced in MY 2005 for all engines. G13 has been introduced in MY 2008 as factory filling and service.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 2 most recent
The complaint is about the motors losing oil every 1000 miles a 1qt is need each time. The engine is caused and burns oil fast to the motor to lose oil more rapidly. Needs to be replaced. My motor is losing oil! And so do other models havening this problems isnt good.
Car started misfiring and within less than 5 miles in the highway then started to build up smoke inside the cabin, car then stopped and towed to a mechanics who confirm the diagnosis of misfiring of 3 cylinders and found overheating of the passenger side catalytic converter that lead to a melting a connector of the transmission. *tr
Had engine trouble with your 2005 Audi S4?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2005 Audi S4?
It's a documented issue but not catastrophic. 4 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 4 complaints filed, engine issues most often appear around 74,867 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2005/Audi/S4.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.