Feel a buzz through the seat at every red light, or a thump every time you get back on the throttle? On a B8 or B8.5 S4, that is usually the engine mounts asking for retirement. Audi B8 S4 engine mounts are fluid-filled hydraulic units, and with enough miles (and enough right-foot enthusiasm) they leak, tear and let the supercharged 3.0T move around more than it should. Here are the failure signs, what the job costs, and how to choose between our three replacements, starting with the TruSport DynaCore 65A engine mounts for the B8 S4.
Why Audi B8 S4 Engine Mounts Fail
Each side of the engine sits on a mount bolted to the front subframe. The factory mounts are hydraulic: a rubber spring carries the weight while fluid moving between internal chambers damps vibration. On many B8 and B8.5 cars, each mount also has a solenoid valve (N144 on the left, N145 on the right) that lets the engine computer change how it damps. Clever, comfortable and, unfortunately, mortal.
The rubber neck under the center plate tears, the fluid weeps out, and the mount slowly loses its grip on the engine. Owner reports on the big Audi forums run from the high 30,000-mile range to well past 100,000 miles, and owners say added power speeds that up. Leaks hide behind heat shields, too: one owner's car stored a fault code about 2,000 miles after a leak he never saw.
Signs Your B8 S4 Engine Mounts Are Done
The symptoms owners describe most:
- ✅ Vibration at idle in gear: a buzz through the seat, wheel or shifter that eases off in Park or Neutral.
- ✅ Clunks and thumps: a knock on and off the throttle, on hard shifts or under hard braking.
- ✅ A jerky, sloppy drivetrain: lash on throttle transitions and sloppier shifts.
- ✅ A shaking shifter on manual cars: one owner traced his to a failed passenger-side mount.
- ✅ Dark, oily residue on a mount: leaked damping fluid, often spotted only when the car is on a lift.
- ✅ A stored mount fault: a solenoid valve code for N144 or N145, sometimes with no check engine light.
Quick check: have a helper set the parking brake, hold the brake pedal firmly and shift between Drive and Reverse at idle while you watch the engine from the side, never from the front. A big lurch or clunk points at the mounts.
What B8 S4 Engine Mount Replacement Costs
The parts are only half the bill. Genuine Audi mounts for the 3.0T S4 are sold per side, commonly listed as 8R0199381AD (left) and 8R0199381AE (right), at around $570 list each. That is the Audi Tax in its purest form: premium money for the same fluid-filled design that just failed you. Audi used other numbers by year and transmission, so match your VIN first.
One B8.5 S4 owner was quoted $580 in labor by an independent shop, about $1,000 with parts. Home mechanics report about four hours with an engine support bar.
What to Look For in a Replacement Engine Mount
Hold every option to this checklist:
- ✅ Active mount electronics handled: an emulator or plug for the N144 and N145 connectors, so no stored faults and no coding.
- ✅ A stated rubber hardness: on the Shore A scale, a higher number means harder rubber.
- ✅ A fix for the real failure: no fluid to leak (or a fluid core inside a firmer rubber body) and a shape that does not pile load onto the neck.
- ✅ A matched pair, so both sides share the load evenly.
- ✅ Real fitment support: fitment by chassis and engine, plus a human who will check your VIN.
Vorsprung Mounts vs Name-Brand vs Dealer Parts
The short version: genuine Audi mounts list for around $570 per side and bring back the same fluid-filled design. Typical name-brand performance pairs run about $450 to $680, mostly solid rubber in cast or billet bodies. Our pairs cost $249.99 (TruSport DynaCore 65A) or $299.99 (TruSport 65A and TruComfort 45A), each with a built-in plug-and-play emulator.
| Vorsprung | Typical name-brand mounts | Dealer (genuine Audi) | |
|---|---|---|---|
| Construction | Aluminum housing with void-free 45A or 65A rubber, or 65A around a fluid core | Mostly solid rubber in cast or billet bodies | Hydraulic and fluid-filled, with a solenoid valve |
| Hardness choices | 45A, 65A and 65A DynaCore | Usually a street and a track grade | One factory feel |
| Active mount electronics | Built-in emulator | On many; check each listing | Factory solenoid (N144, N145) |
| Price | $249.99 to $299.99 per pair | About $450 to $680 per pair | About $570 list per side |
| Weak point | Designed around the torn neck and leaks | Varies | Fluid leaks, torn rubber (owner reports) |
For most tuned daily drivers, the TruSport DynaCore 65A engine mount pair is the sweet spot: 65A control, a fluid core for the buzz and the lowest price here.
Shop TruSport DynaCore 65A Mounts, $249.99
✅ Vorsprung-designed mounts with built-in emulators · ✅ Fitment help by VIN at help@vorsprungautowerk.com · ✅ Free US shipping on orders over $425
TruComfort 45A vs TruSport 65A vs DynaCore: Which One Suits You?
All three swap the factory hydraulic design for an aluminum-housed mount with a built-in emulator. The question is how much engine you want to feel.
TruComfort 45A: the daily driver's mount ($299.99)
The TruComfort 45A engine mounts use a void-free 45A rubber element, the softer of our two ratings, tuned for stability without punishing NVH (noise, vibration and harshness). No fluid to leak, no cavities to tear. Pick it for a stock or lightly modified S4 that lives in traffic. Its listing photos show a revised mold with a relief pocket and raised side ribs under the center plate, designed to spread load away from where solid-dome mounts tear.
TruSport 65A: maximum engine control ($299.99)
The TruSport 65A engine mounts use a void-free 65A element that holds its shape under load without packing down. Expect a firmer, more connected feel: less drivetrain movement, cleaner shifts and quicker throttle response. Firmer rubber also passes a little more vibration into the cabin, which is exactly why the 45A exists. Pick the 65A for a tuned car, a manual that sees hard launches, or track days.
TruSport DynaCore 65A: control with a fluid core ($249.99)
The TruSport DynaCore 65A mounts wrap the same 65A structure around a tuned internal fluid chamber (the listing calls it a dynamic isolation core) built to soak up high-frequency vibration. Current stock is discounted for minor cosmetic paint defects on the housing, with the same mechanical function per the listing, making it the value pick for a tuned daily driver.
What's in the Box and Why It Matters
Every listing is a pair, one mount per side. Each has an aluminum housing with a laser-engraved Vorsprung Autowerk logo, the rubber element you chose and a built-in emulator that plugs into the factory harness on cars with active mounts; the listings state zero warning lights, zero coding and zero modification. Bolts are not listed as included, so plan on fresh factory hardware.
While the car is up, add the TruShift transmission mount ($19.99). Its 65 durometer rubber cuts drivetrain slop at the back of the gearbox. Our Audi transmission mount upgrade guide explains the shift-feel gains, and the Audi engine and transmission mount collection has every option in one place.
Fitment: B8 and B8.5 S4, S5, SQ5, A4, A5 and Q5
Per the listings, all three pairs fit the 2008 to 2016 Audi B8 and B8.5 platform: the S4, S5 and SQ5 with the 3.0T supercharged V6 (EA837), plus the A4, A5, allroad and Q5. The TruSport DynaCore 65A fitment table and the TruSport 65A fitment table add the 3.2 V6 A4, A5 and Q5, while the TruComfort 45A fitment table lists the 2.0T and 3.0T. The tables also include some C7 A6 and A7 and D4 A8 models.
Driving a 4.2 V8 S5 (not in the engine mount tables) or a 2017 SQ5? Email your VIN to help@vorsprungautowerk.com before you order.
Install Notes: Time, Tools and Tips
This is a real job, not a lunch-break swap. One mount maker's install guide quotes four to five hours for an experienced tech; owners report about four at home with an engine support bar.
Tools: an engine support bar or hoist (a three-point bar is the owner favorite), jack stands, a breaker bar, a ratchet with 6 and 12 inch extensions, 18, 16, 13 and 10 mm sockets, a T27 Torx and an 8 mm triple-square bit.
- ✅ Pick your route. The factory way does one side at a time with the engine supported from above: the right side is easy, while the left means moving the oil cooler aside and getting the A/C compressor out of the way. Many owners lower the front subframe about an inch (25 to 35 mm) instead and call it far less work.
- ✅ Mark the subframe before lowering it, then get an alignment check, since its position affects alignment.
- ✅ Plan on new bolts. Owners recommend fresh stretch (torque-to-yield) hardware, torqued to factory spec.
- ✅ S tronic cars also have an ATF line bracket to unbolt near the right mount.
- ✅ Plug in the factory N144 and N145 connectors before the engine goes back down.
- ✅ Do both sides and the transmission mount in one visit and pay for access once.
Building the car further? Our B8/B8.5 Audi S4 mods roadmap puts mounts in Stage 0, performance parts for the Audi S4 sorts the rest by budget, and the Audi S4 supercharged ownership guide covers what else wears out.
Audi B8 S4 Engine Mounts FAQ
How do I know if my B8 S4 engine mounts are bad?
Watch for vibration at idle in gear that eases in Park or Neutral, clunks on and off the throttle, sloppy shifts, oily residue on the mounts or a stored N144 or N145 solenoid fault.
How long do Audi B8 S4 engine mounts last?
No fixed interval. Owners report failures from the high 30,000-mile range to well past 100,000 miles, and added power speeds up the wear. Inspect them whenever the car is on a lift.
How much does it cost to replace engine mounts on a B8 S4?
Genuine Audi mounts list for around $570 per side. One B8.5 S4 owner was quoted $580 in labor at an independent shop, about $1,000 with parts. Vorsprung mount pairs cost $249.99 to $299.99.
Will aftermarket engine mounts throw a code on my S4?
They can if the active mount electronics are ignored, since the engine computer watches each mount's solenoid circuit. TruSport and TruComfort mounts have built-in plug-and-play emulators, and the listings state no warning lights and no coding.
Do performance engine mounts make the cabin vibrate more?
Firmer rubber passes more vibration, so a 65A mount feels more connected than a 45A. TruComfort 45A is the comfort pick, TruSport 65A the firmest, and the DynaCore adds a fluid core for high-frequency buzz.
Should I replace both engine mounts at the same time?
Yes. Replacing only one side can cause uneven load distribution, faster wear on the new mount and poor drivetrain alignment, which is why every Vorsprung engine mount listing is a pair.
Can I keep driving on a bad engine mount?
Usually for a short time, but do not let it ride. Extra engine movement strains hoses, belts and exhaust joints, and a mount that lets go can let the engine hit nearby parts.
Should I replace the transmission mount at the same time?
Yes, since you are already under the car. The TruShift transmission mount is $19.99, uses 65 durometer rubber and fits the 2010 to 2017 B8 and B8.5 S4 and S5 per its listing.
Bottom Line on Audi B8 S4 Engine Mounts
Factory Audi B8 S4 engine mounts fail the same way every time: the rubber tears, the fluid leaks and the drivetrain gets sloppy. Replace them as a pair, handle the active mount electronics and choose the hardness you can live with. Comfort first? TruComfort 45A. Maximum control? TruSport 65A. A tuned daily driver that wants both? The TruSport DynaCore 65A engine mounts for B8 and B8.5 Audis at $249.99 are the easy call.
Shop TruSport DynaCore 65A Engine Mounts, $249.99
Drive the difference. Drive Vorsprung.
Prices checked October 21, 2026 and subject to change. Labor figures are owner-reported or typical shop quotes.
