The Audi S4 supercharged era ran from 2010 to 2016 in the US, and it produced one of the best-loved Audis of the modern age: a 3.0T V6 with instant, belt-driven boost, a proper manual option and quattro grip. It also came with a valley full of plastic parts that crack at the worst possible moment. If you own one or you are shopping for one, this guide covers what is great, what fails, and the order to fix and upgrade it. Spoiler: the first purchase for most cars is our OE Ultimate Under Supercharger Kit for the B8.5 S4.
Why the Audi S4 Supercharged Is Worth Owning
The B8 and B8.5 S4 uses the EA837 3.0 TFSI: a V6 with an Eaton Roots-type supercharger nestled in the V of the engine, rated at 333 hp and 325 lb-ft in US trim. Because the blower is driven by the crank, boost arrives as soon as you touch the throttle. No waiting for a turbo to spool, no lag to manage.
- ✅ Throttle response. Torque shows up low and stays flat, which makes the car feel bigger than its displacement.
- ✅ Gearbox choice. A six-speed manual or the seven-speed S tronic dual-clutch.
- ✅ quattro traction. The B8 S4 uses a mechanical center differential, and the optional sport differential adds rear torque vectoring. Our Torsen vs Haldex guide explains how it differs from other AWD systems.
- ✅ Tunability. Software, a pulley swap and cooling transform the car without touching the internals.
- ✅ The sound. That supercharger whine never gets old.
Wondering how it stacks up against the newer turbo car? Our turbo Audi S4 guide covers the B9 and why most B8 owners should skip the turbo swap idea.
What Fails on the B8 and B8.5 S4
The engine's core is tough. The trouble lives in the parts Audi made from plastic and then buried under the supercharger, where engine heat cooks them year after year.
Under the supercharger
- ✅ Thermostat housing. The plastic housing warps and cracks, and the first sign is often a low coolant warning or a sweet smell after a drive.
- ✅ Coolant pipes and heater pipe. Plastic coolant lines turn brittle with heat cycling and start weeping.
- ✅ Water pump. A known wear item on the 3.0T. Leaks and failing bearings are common as cars age.
- ✅ PCV valve. When the diaphragm tears you get a whistle, a rough idle and lean or idle codes. Read our Audi PCV valve guide for the full symptom list.
Every one of those parts requires the supercharger to come off. The parts are cheap. The labor is not. That is why replacing one and leaving the rest is how people end up paying for the same job twice.
Elsewhere on the car
- ✅ Carbon buildup. The Gen 1 3.0T is direct-injection only, so intake valves collect carbon over time and need periodic cleaning.
- ✅ Supercharger isolator rattle. A rattle at idle from the blower drive is a common complaint on higher-mileage cars.
- ✅ Oil leaks. The oil filter housing and front main seal are frequent seepers. See our oil filter housing gasket guide.
- ✅ Belt drive. Worn tensioner and idler pulleys show up as chirps and belt wear. Our tensioner pulley replacement cost post covers it.
- ✅ Engine mounts. Tired fluid-filled mounts add vibration and a sloppy feel on throttle.
Buying a Used Audi S4 Supercharged: Checklist
- ✅ Service records showing whether the thermostat, water pump and PCV have been done, and when
- ✅ Coolant level, and any crust or residue around the back of the supercharger
- ✅ A cold start: listen for rattles at idle and check for rough running
- ✅ An OBD scan for stored misfire, lean or thermostat codes
- ✅ S tronic cars: proof of transmission fluid services on schedule
- ✅ Signs of tuning, and whether the seller still has the stock software
A car with the valley already refreshed is worth paying more for. A car without it should be priced like it needs the job, because it probably does.
Fix It Once: Vorsprung Kit vs Name-Brand vs Dealer
The fix is a full refresh of the valley while the blower is off. The dealer replaces the failed part with the same plastic part. Typical name-brand kits cover the basics, often at premium prices. Our B8.5 S4 Under Supercharger Kit bundles billet and metal upgrades with OE-supplier parts at $649.99.
| Vorsprung Under Supercharger Kit | Typical name-brand kit | Dealer repair | |
|---|---|---|---|
| Thermostat housing | Billet aluminum | Varies, often OE plastic | OE plastic |
| Water pump | Graf metal-impeller pump | Varies | OE replacement |
| PCV valve | OE Hengst | Usually included | OE |
| Gaskets and injector seals | Elring intake and injector seals included | Sometimes separate | Billed per part |
| Audi Tax | None | Brand premium | Full dealer pricing plus labor |
Shop the B8.5 S4 Under Supercharger Kit, $649.99
✅ OE-supplier parts from Graf, Hengst and Elring plus billet upgrades ✅ S4 fitment help from real 3.0T owners ✅ Fast US shipping
Recommended Parts for the Supercharged S4
OE Ultimate Under Supercharger Kit, Gen 1 B8.5 and C7 ($649.99). Billet thermostat assembly, aluminum heater pipe, Graf metal water pump, OE Hengst PCV valve, Elring upper and lower intake manifold gaskets, the PCV-to-supercharger adapter pipe and an Elring injector seal kit.
OE Ultimate Under Supercharger Kit, B8 ($574.99). The version for 2010-2012 cars, with the correct water pump and PCV part numbers plus the crankcase breather hose and clamp.
While you are in there: the GLT TruSeal PCV diaphragm upgrade ($19.99) for PCV relocation setups, the billet front main seal ($124.99) if yours is seeping, and for S tronic cars the billet DSG oil filter cap kit ($54.99). If your car shudders on throttle, the TruSport engine mounts ($299.99) firm things up.
Shop the whole Audi 3.0T under supercharger kits collection or read our Audi 3.0T under supercharger kit guide.
Fitment: Which S4 Kit Do You Need?
For 2010-2012 B8 S4 (and 2010-2012 S5), use the B8 Under Supercharger Kit. For 2013-2016 B8.5 S4, use the B8.5 Under Supercharger Kit, which also covers B8.5 S5, SQ5, Q5 3.0T, C7 A6 and A7 through 2015. If you have a VIN in hand and still are not sure, ask us before you order.
The Smart Upgrade Order
Once the valley is sorted, the S4 rewards a simple sequence: reliability first, then airflow and software, then pulley and cooling together, then brakes, suspension and wheels to match. Our Audi S4 mods roadmap lays out each stage in detail, and our guide to performance parts for Audi S4 shows what to buy in each category by budget.
Install Notes
- ✅ Budget a full day of shop time for supercharger removal and reinstallation, or a weekend in your own garage.
- ✅ Replace the intake manifold gaskets and injector seals whenever the blower comes off. They are included in the kit for a reason.
- ✅ Bleed the cooling system carefully and recheck coolant after the first few drives.
- ✅ Take the chance to inspect for carbon and plan a valve cleaning if needed.
Audi S4 Supercharged FAQ
What years was the Audi S4 supercharged?
In the US, the supercharged 3.0T S4 was sold from the 2010 to 2016 model years: the B8 from 2010 to 2012 and the facelifted B8.5 from 2013 to 2016. The 2018 B9 S4 switched to a turbocharged V6.
How much power does the supercharged S4 make?
The B8 and B8.5 S4 is rated at 333 hp and 325 lb-ft of torque in US trim from its 3.0 TFSI supercharged V6.
Is the Audi S4 supercharged reliable?
The engine core is strong, but plastic cooling parts, the PCV valve and the water pump under the supercharger are known failure points. Replacing them together with metal and OE-supplier parts makes the car far more dependable.
What is an under supercharger kit?
A bundle of the parts that are only reachable with the supercharger removed: thermostat housing, water pump, PCV valve, heater pipe, intake gaskets and injector seals. Doing them together avoids paying the removal labor twice.
What should I check before buying a supercharged S4?
Look for service records on the thermostat, water pump and PCV, check for coolant residue behind the supercharger, listen for rattles at a cold idle, scan for codes, and confirm S tronic fluid services.
Should I buy a B8 S4 or a B9 S4?
Buy the B8 or B8.5 if you want supercharger response, a manual option and lots of affordable upgrade paths. Buy the B9 if you want the newer turbo platform and an eight-speed automatic.
What is the first mod for an Audi S4 supercharged?
Reliability. Refresh the parts under the supercharger first, then move on to intake, throttle body, software, pulley and cooling.
Bottom Line on the Audi S4 Supercharged
The Audi S4 supercharged is one of the best-driving Audis you can buy for the money, as long as you deal with the plastic under the blower before it deals with you. Refresh the valley once, with parts that won't crack again, and you have a car that is ready for everything on the upgrade list. Start with the OE Ultimate Under Supercharger Kit for the B8.5 S4.
Shop the B8.5 S4 Under Supercharger Kit, $649.99
Drive the difference. Drive Vorsprung.
Prices checked September 25, 2026 and subject to change.
