This 2018 Audi S3 Premium Plus came in with a check engine light on for a faulty thermostat at 53,610 miles. But the thermostat code was just the beginning of what this EA888 engine needed.
What We Found: More Than Just a Thermostat
During previous visits and digital inspections, we had noticed staining and minor traces of oil in the coolant reservoir. That is a telltale sign of a failing oil cooler and/or accessory bracket — the assembly where the oil filter and oil cooler attach to the engine block, passing both oil and coolant through it.
This is a well-known failure point on the EA888 engine. When the contamination between oil and coolant is slight, it is impossible to pinpoint whether the oil cooler itself or the bracket has developed micro fractures. We have seen it before — replace just the oil cooler, and 10,000 to 20,000 miles later the same issue comes back because the bracket was the actual culprit. The bracket is also known to simply start leaking oil from its mounting surface against the block.
The only reliable repair is to replace both the oil cooler and the accessory bracket together.
Smart Timing: One Job Saves Significant Labor
This customer had fortunate timing. The water pump and thermostat housing needed replacement anyway due to the check engine light. The oil cooler and bracket repair overlaps heavily with that job. By doing both at the same time, the labor savings were massive — and with our free loaner cars, the extra shop time is no inconvenience — much of the teardown and access work only had to happen once instead of twice.
Carbon Cleaning: The Smart Add-On
Whenever we replace the water pump and thermostat housing on these engines, we prefer to remove the intake manifold for better access. With the manifold already off, we are looking right at the intake valves — and on a direct-injection engine with 53,000 miles, carbon buildup is inevitable.
Rather than put it all back together and have the customer return later for a separate carbon cleaning, we handle it while everything is apart. The before-and-after photos speak for themselves.
The intake manifold tumble flaps were coated as well:
New Fuel Injectors
With the intake manifold off and the carbon cleaning done, we also recommended new fuel injectors. Whether injectors should be replaced depends on the specific engine code, age, and mileage of the vehicle. On this S3 at 53,000 miles, it was the right call — and with everything already apart, the additional labor is minimal.
All Back Together
This S3 left with a new water pump, thermostat housing, oil cooler, accessory bracket, fuel injectors, and freshly cleaned intake valves and manifold. All OEM parts, all covered by our 3-year/36,000-mile warranty.
This is exactly the kind of job where an independent Audi specialist saves you real money. Overlapping repairs done together means you pay for the labor once, not twice. We see it all the time on these EA888 engines and know exactly what to look for.
If your Audi or VW has a check engine light, coolant warning, or you have noticed anything off with your engine temperature, schedule an appointment or give us a call at (603) 207-4004.