Audi S8 (2012-2021) Engine Oil Pressure Switch: A Complete Replacement Guide
An oil pressure warning on your S8's 4.0T engine is serious; understand the causes and high-labor costs before you replace the switch.
- An oil pressure warning could be a symptom of the critical 21H7 turbo oil strainer recall; investigate this with a dealer immediately.
- Replacement is an extremely expensive, high-labor job because the switch is buried deep in the engine valley.
- Due to the high labor cost, you must use a high-quality OEM or premium aftermarket part (like Vemo or Facet) to avoid a repeat repair.
- Never drive your S8 with a low oil pressure warning light on. Stop the engine immediately and have the vehicle towed to prevent catastrophic damage.
Symptoms of a Failing Oil Pressure Switch
A bad oil pressure switch can be the cause of several confusing and serious warnings. The most common sign is the red oil pressure warning light on your dashboard, which may flicker or stay on constantly. This can happen even if your engine oil level is correct. You may also see the Check Engine Light, often with trouble code P0524, which means "Engine Oil Pressure Too Low". In some cases, the switch itself can fail and leak oil from its plastic body or electrical connector.
Warning: Is It the Switch or the Turbo Oil Strainer?
For 2013-2017 S8 models, an oil pressure warning is a primary symptom of a critical safety recall (Audi Code: 21H7 / NHTSA Campaign: 22V178000). A small mesh oil strainer for the turbochargers can get clogged, starving the turbos of oil and leading to catastrophic failure. Since the warning light is the same for a bad switch and a clogged strainer, you must investigate this recall first. Contact an Audi dealer with your vehicle's VIN to confirm if the recall service has been performed.
Choosing the Right Aftermarket Part
The oil pressure switch is located deep in the valley of the engine, underneath the turbochargers. Replacing it is an extremely labor-intensive job that can take a professional mechanic 8-12 hours. Because the labor cost is so high, the brand of part you choose is critical. Saving a few dollars on a budget part is not worth the risk of having to pay for the same repair twice.
- Premium Aftermarket (Recommended): Brands like Vemo and Facet are known in the Audi community as reliable, high-quality alternatives to OEM. They are engineered to meet original specifications and are a safe choice for this repair.
- Standard Aftermarket: Brands like Walker Products manufacture parts to meet or exceed original standards and can be a reliable option.
- Budget Brands: Given the extreme labor cost, using a low-cost, unproven brand is a significant risk that is not recommended for this specific part.
Pro Tip: Replace It During Other Engine Valley Service
The most cost-effective time to replace the oil pressure switch is when other major work is already being done in the engine valley. If your S8 is having the turbo oil strainer recall performed, or if the PCV / oil separator is being replaced, ask your mechanic to replace the oil pressure switch at the same time. This will save you from paying the high labor cost for this job alone in the future.
Cost to Replace the Engine Oil Pressure Switch on a 2012-2021 Audi S8
| Part Type | Part Cost | Estimated Labor Cost | Estimated Total Cost |
|---|---|---|---|
| New Aftermarket | $13 - $59 | $1400 - $2200 | $1413 - $2259 |
| New OEM | $90 - $120 | $1400 - $2200 | $1490 - $2320 |
Cost estimates are based on industry data and may vary by location and shop. The high labor cost is due to the part's difficult-to-access location.
Frequently Asked Questions (FAQ)
Where is the oil pressure switch located on the 4.0T engine?
The oil pressure switch is located deep in the "V" or valley of the engine, between the cylinder heads. It is underneath the turbocharger assembly and other components, making it very difficult to access.
Can I replace the Audi S8 oil pressure switch myself?
This is not recommended for a DIY project. The replacement requires extensive disassembly of the top of the engine, including the charge air cooler and potentially the turbochargers. This job requires special tools and expert knowledge and should be left to a professional mechanic.
What happens if I ignore a low oil pressure warning?
You should never ignore this warning. Continuing to drive can lead to a complete lack of lubrication, causing immediate and catastrophic engine damage that could require a full engine replacement. This is especially true for the turbochargers, which are very sensitive to oil supply.
Is an aftermarket switch good enough for my S8?
Yes, a high-quality aftermarket switch from a reputable brand like Vemo or Facet is a reliable and safe option. Because the labor for this repair is so expensive, it is critical to choose a premium part to ensure longevity and avoid doing the job a second time.
Technical Specifications
OEM Part Numbers: 079919081A
The Audi S8 4.0T engine uses multiple switches to monitor different pressure stages. The primary low-pressure switch triggers the main dashboard warning. Replacement requires accessing the engine valley.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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- Symptoms of a Failing Oil Pressure Switch
- Warning: Is It the Switch or the Turbo Oil Strainer?
- Choosing the Right Aftermarket Part
- Pro Tip: Replace It During Other Engine Valley Service
- Cost to Replace the Engine Oil Pressure Switch on a 2012-2021 Audi S8
- Frequently Asked Questions (FAQ)
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