Instant boost off idle, a supercharger whine that makes tunnels feel like concert halls, and a V6 that takes a pulley swap like it was expecting one. That is the Audi 3.0T supercharged engine, the EA837 3.0 TFSI that powered everything from the B8 S4 to the Q7. It is also an engine that hides a valley full of plastic cooling parts under its blower. This guide explains Gen 1 vs Gen 2 CREC, which models got which, the failures every owner should plan for, and how our OE Ultimate Under Supercharger Kit for the Gen 1 B8.5 Audi 3.0T fixes them in one job.
If you searched "Audi V6 supercharged," you are in the right place too. Audi only ever put a factory supercharger on this V6 family, so the two terms describe the same engine. (Wondering about the V8? See Audi V8 supercharged.)
What Is the Audi 3.0T Supercharged Engine (EA837)?
The EA837 3.0 TFSI is a 90-degree, direct-injected, all-aluminum V6 with a Roots-type Eaton R1320 TVS supercharger sitting in the valley between the cylinder heads. Two air-to-water intercooler cores live inside the supercharger housing, fed by their own low-temperature coolant loop and front heat exchanger. Audi debuted it in 2008 at 290 hp, dropped compression from the old 3.2 V6's 12.5:1 to 10.3:1 to make room for boost, and then spent a decade tuning the same hardware up and down the lineup.
Why do enthusiasts love it? Because a supercharger is belt-driven, boost arrives with the throttle instead of waiting for exhaust energy. Why do the same enthusiasts curse it? Because the blower sits on top of the thermostat, water pump, PCV valve, and coolant plumbing, so a $60 part can hide under a job that takes a full day of labor to reach.
Where you find it
- B8/B8.5 S4 and S5 (2010-2016 S4, 2010-2017 S5), 333 hp in US trim
- B8.5 Q5 3.0T and SQ5 (2013-2017), with the SQ5 rated at 354 hp
- C6 A6 3.0T (2009-2011) and C7 A6/A7 3.0T (2012-2015)
- D4 A8 3.0T and 4L Q7 3.0T, plus the VW Touareg
- Gen 2 CREC: 2016-2018 C7.5 A6/A7 (333 hp), 2015-2018 A8, and the 4M Q7 until the switch to turbo power
Gen 1 vs Gen 2 CREC: What Changed
Gen 1 covers cars built from 2009 through roughly 2015, plus the B8.5 S4, S5, Q5 and SQ5 models that run to 2016 and 2017. The later CREC engine (Gen 2) looks nearly identical from the fender, still runs the R1320 blower, and still hides its cooling parts in the valley. The differences matter when you order parts, though:
- Engine management: CREC cars moved to a newer Simos 16 ECU, so software and diagnostics are not interchangeable with Gen 1.
- Cooling hardware: Gen 1 uses the 06E121111AL-style thermostat and a plastic heater pipe (06E121065N). CREC uses a different thermostat (06E121111AT) and no plastic heater pipe.
- PCV valve: Gen 1 cars use Hengst 06E103547AC (early), 06E103547AH or Rein 06E103547AK (C7 A6/A7 and 4L Q7), while CREC uses 06E103547AF.
- Seals and gaskets: CREC takes different lower intake manifold gaskets and a different injector seal kit (06E998907F vs 06E998907E).
The fastest way to know? Read the engine code on your build sticker in the spare tire well or owner's manual, or send us your VIN. Ordering by "it's a 3.0T" alone is how people end up with a thermostat that almost fits.
Known Audi 3.0T Supercharged Engine Failures
None of these are secrets, which is exactly why the dealer loves them. Here is the short list, roughly in the order they show up.
1. Thermostat housing
The factory housing is plastic, it lives in the hot valley, and it spends years soaking in coolant. It gets brittle, cracks, and leaks, often into the valley where you cannot see it until the low-coolant light pops on. Symptoms: sweet smell after a drive, slowly dropping coolant, temperature swings. Our billet fix comes in Gen 1 non-Evo and Gen 2 CREC versions, machined from 6061-T6 and pre-assembled with a thermostat.
2. Coolant crossover pipe
The composite crossover and supply pipe (06E121045BB and earlier AA, AJ, AK revisions) heat-cycles itself brittle and weeps at its O-rings. Cheap part, ugly failure. Replace the 3.0T coolant crossover pipe proactively whenever the blower is off.
3. Water pump
Pumps on this engine eventually weep from the seal. Replacing one with another plastic-impeller pump is a very Audi Tax way to schedule the same job twice. The Graf PA1228 water pump uses a metal impeller and is included in our kits.
4. PCV valve
The PCV valve diaphragm tears with age. Expect a whistle or hiss at idle, rough idle, lean codes, oil consumption, and sometimes a hard-to-remove oil cap from crankcase vacuum. The correct Hengst part depends on generation: 06E103547AH for most Gen 1 cars or 06E103547AF for CREC. The companion PCV-to-intake pipe is also a known cracker, so check the 06E103207P/AM PCV pipe while you are there. Owners who are tired of this whole arrangement can relocate the valve with our billet PCV housing adapter.
5. Carbon buildup
Direct injection sprays fuel straight into the cylinder, so nothing washes the backs of the intake valves. Oil vapor from the PCV system bakes on over time, and high-mileage engines can develop rough idle and misfires. The cure is a walnut-blast cleaning, and on this engine that means pulling the supercharger and intake. Translation: combine it with your valley refresh and use fresh intake manifold gaskets, such as our GLT TruSeal intake manifold gasket set.
What to Look For in a Fix
- ✅ Metal where plastic failed: billet thermostat housing, metal heater pipe on Gen 1, metal-impeller water pump.
- ✅ Correct generation part numbers: Gen 1 and CREC differ on thermostat, PCV valve, gaskets, and injector seals.
- ✅ Every gasket you disturb: upper and lower intake manifold gaskets and injector seals, so you are not reusing crushed rubber.
- ✅ OE-supplier brands: Graf, Hengst, Elring, not mystery parts from direct-from-factory listings.
- ✅ One labor bill: the parts are cheap, the blower removal is not.
Vorsprung Kit vs Typical Name-Brand Kit vs Dealer
The dealer usually replaces what failed today with the same plastic part number and bills you again for the next one. Typical name-brand kits are better, but many still reuse a plastic thermostat housing and price each line item with its own markup. Our Gen 1 B8.5 Audi 3.0T under supercharger kit bundles the billet thermostat assembly, aluminum heater pipe, Graf metal water pump, Hengst PCV valve, Elring upper and lower intake gaskets, the 06E103213 PCV adapter pipe, and an Elring injector seal kit for $649.99.
| Vorsprung Under Supercharger Kit | Typical name-brand kit | Dealer / OEM repair | |
|---|---|---|---|
| Thermostat housing | Billet 6061-T6 aluminum | Often plastic OE-style | Plastic, same as failed part |
| Water pump | Graf metal impeller | Varies | OE pump |
| Gaskets and injector seals | Elring, full set | Varies by kit | Only what the job requires |
| Generation-specific | Gen 1 B8, Gen 1 B8.5, C7 and 4L Q7, 2012 C7, Gen 2 CREC kits | Usually | Yes |
| Future repeat labor risk | Low, whole valley refreshed | Moderate | High, piecemeal repairs |
✅ Billet, Graf, Hengst and Elring components ✅ Gen 1 vs CREC fitment help from real 3.0T owners ✅ Fast US shipping
Shop the B8.5 Under Supercharger Kit, $649.99
Recommended Parts by Generation
Pick the kit that matches your engine, then add the extras that make sense while the belt and blower are off.
- 2010-2012 B8 S4, 2010-2012 S5 Cabriolet, 2009-2011 C6 A6: OE Ultimate Under Supercharger Kit, B8 / C6, $574.99.
- B8.5 S4/S5, Q5 3.0T, SQ5, 2013-2014 D4 A8: OE Ultimate Under Supercharger Kit, Gen 1 B8.5, $649.99.
- C7 A6/A7 built from May 2012 through 2015, 4L Q7 2011-2015: OE Ultimate Under Supercharger Kit, C7 A6, A7 and 4L Q7, $639.99.
- 2012 C7 A6/A7 built before May 2012: the dedicated 2012 C7 under supercharger kit, $674.99.
- CREC (2016-2018 A6/A7, A8, 4M Q7): OE Ultimate Under Supercharger Kit, Gen 2 CREC, $649.99.
- Add-ons while it is apart: the billet supercharger tensioner pulley ($64.99-$111.99) and, if you are going for power next, the TruDrive crank pulley ($224.99-$296.99).
Not sure which you have? Browse the full under supercharger kits collection or read our Audi 3.0T under supercharger kit guide.
Install and Maintenance Notes
An under supercharger service is a big day in a well-equipped home garage or a solid shop job. Plan on draining coolant, removing the cowl and intake pieces, pulling the supercharger, doing the valley, and bleeding the cooling system carefully afterward. Tips from people who have done too many of these:
- Label every vacuum and PCV line before it comes off.
- Replace every O-ring and gasket you touch; reusing them is how a fresh job leaks.
- Inspect the crossover pipe, heater pipe, and coolant hoses while you have daylight in the valley.
- Use the correct G13-spec coolant and bleed properly to avoid air pockets.
- Log fuel trims and coolant temps after the job to confirm PCV and cooling are healthy before adding power.
Once the valley is sorted, the fun stuff is on the table. Our Audi supercharger upgrade guide covers pulleys and porting, and the Audi S4 mods roadmap lays out the build order.
Audi 3.0T Supercharged Engine FAQ
Is the Audi 3.0T supercharged engine reliable?
Yes, the core engine is strong. Most problems are plastic cooling parts, the PCV valve, the water pump, and carbon buildup. Refresh those components under the supercharger and the Audi 3.0T supercharged engine is a durable platform, including when modified.
What is the difference between the Audi 3.0T Gen 1 and Gen 2 CREC?
Gen 1 covers cars from 2009 to about 2015 like the B8/B8.5 S4 and C7 A6, plus B8.5 S4, S5, Q5 and SQ5 cars that run to 2016 and 2017. CREC (Gen 2) is used in 2016-2018 A6/A7, 2015-2018 A8, and the 4M Q7. CREC has a newer ECU and different thermostat, PCV valve, gasket, and injector seal part numbers.
Is the Audi V6 supercharged engine the same as the 3.0T?
Yes. Audi's factory supercharged V6 is the EA837 3.0 TFSI, badged 3.0T. Later B9 S4 and SQ5 models switched to the turbocharged EA839, which is a different engine.
What are the symptoms of a failing Audi 3.0T thermostat housing?
Slowly dropping coolant, a sweet coolant smell after driving, coolant pooling in the valley, low-coolant warnings, and fluctuating temperature readings.
How do I know if my 3.0T PCV valve is bad?
Common signs are a whistle or hiss at idle, rough idle, lean fuel trim codes, increased oil consumption, and strong vacuum when you remove the oil cap.
Do you have to remove the supercharger to replace the thermostat on a 3.0T?
On these engines the thermostat, water pump, and PCV valve sit under or around the supercharger, so the blower comes off. That is why replacing everything in the valley at once saves repeat labor.
Which models use the Audi 3.0T supercharged engine?
B8/B8.5 S4 and S5, B8.5 Q5 3.0T and SQ5, C6 and C7 A6, A7, D4 A8, 4L and 4M Q7, and the VW Touareg. Model years and generation determine which parts fit.
Bottom Line
The Audi 3.0T supercharged engine is one of the best-sounding, best-responding V6s Audi ever built, and its weak points are known, boring, and fixable. Figure out whether you have a Gen 1 or a Gen 2 CREC, then fix the valley once with the right Audi 3.0T under supercharger kit (or the Gen 2 CREC version) before you start chasing boost. Reliable first, fast second, smug forever.
Shop the Under Supercharger Kit, $649.99
Drive the difference. Drive Vorsprung.
Prices checked October 19, 2026 and subject to change.
