2006-2010 BMW M5 & M6 S85 V10 Valve Cover Guide: Leaks, Symptoms & Replacement
An in-depth look at the common valve cover and gasket issues on the S85 V10 engine found in the E60 M5 and E63/E64 M6, including diagnosis, replacement tips, and cost.
- The most common failure is the rubber gasket, not the magnesium cover itself, leading to a strong burning oil smell as oil drips on the exhaust.
- When buying a used cover, check for cracks and ensure the inner coating in the gasket channel is not peeling, as this will prevent a proper seal.
- Replacement is a labor-intensive DIY job (4/5 difficulty) due to the need to remove the intake plenum and other components for access.
- Always replace the 34 rubber bolt grommets along with the main gaskets to ensure even clamping pressure and a long-lasting seal.
Known Issues, TSBs, and Recalls
While there are no specific recalls or Technical Service Bulletins (TSBs) for the S85 engine's valve covers or their gaskets, these vehicles were subject to other recalls. One notable recall for the 2006-2010 M5 and M6 models involved an incorrectly attached positive battery cable in the trunk, which could lead to overheating and a potential fire risk. Owners can verify if their vehicle has had this, or any other recall service performed, by contacting a BMW dealer or using the NHTSA's VIN check tool.
Symptoms of a Failing Valve Cover or Gasket
The most common failure point is not the magnesium cover itself, but the rubber gasket that seals it to the cylinder head. Over time, constant exposure to the engine's intense heat causes the rubber to harden, become brittle, and crack. This prevents it from creating a proper seal, leading to oil leaks.
1. Burning Oil Smell
This is often the first and most alarming symptom. The S85's exhaust manifolds are located directly below the valve covers. As oil seeps from the failing gasket, it drips onto the hot exhaust, burning off and creating a strong, acrid smell that is easily drawn into the passenger cabin through the ventilation system. In severe cases, this can be mistaken for an engine fire.
🎬 Watch a breakdown of common failing valve cover symptoms.2. Visible Oil Leaks and Smoke from Engine Bay
You may notice wet, oily patches or active drips on the sides of the engine block, particularly around the seam where the valve cover meets the cylinder head. As the leak worsens, enough oil can burn off the exhaust to produce visible smoke from under the hood, especially after the car has been driven and is idling at a stop.
3. Oil in Spark Plug Wells
The valve cover gasket set includes seals for the spark plug tubes. When these inner seals fail, oil can leak into the spark plug wells, pooling around the ignition coils and spark plugs. This can lead to engine misfires, a rough idle, and a Check Engine Light. If you pull an ignition coil and find its tip coated in oil, a leaking valve cover gasket is the culprit.
🎬 See how oil in the wells causes engine misfires.4. Low Engine Oil Level
A significant leak will lead to a noticeable drop in the engine's oil level over time, potentially triggering the low oil warning light. The S85 engine is known for its oil consumption, but a sudden increase should prompt an inspection for leaks.
Warning: While the primary failure is usually the gasket, the magnesium covers themselves can be a problem. The factory coating inside the gasket channel can peel away, creating a poor sealing surface that a new gasket can't fix. The covers can also crack if bolts are over-tightened or corrode over time.
Buying a Used S85 Valve Cover
For a high-performance, specialized engine like the S85, buying a used OEM valve cover can be a smart move, but careful inspection is critical. New OEM covers are extremely expensive, making a quality used part a great value.
- Check for Cracks: Meticulously inspect the entire cover, especially around the bolt holes and in the corners. Magnesium can be brittle, and a small crack can quickly worsen under engine vibration and heat cycles.
- Inspect the Gasket Channel: This is the most important area. Run your finger along the entire channel where the gasket sits. Look and feel for any peeling, flaking, or bubbling of the internal coating. If the coating is compromised, the cover will likely never seal properly, even with a new gasket.
- Look for Corrosion: Check for white, powdery corrosion (oxidation) on both the inside and outside surfaces. Heavy corrosion indicates the part may have been exposed to the elements or came from a poorly maintained engine.
- Verify Flatness: Place the cover on a known flat surface and check for any warping or rocking. A warped cover will not seal correctly against the cylinder head.
- Part Number Verification: Ensure the part numbers match your requirement. The S85 uses left and right-specific covers. For example, part number 11127891023 is for the right side (cylinders 6-10) and supersedes 11127834622.
Pro Tip: When replacing the valve covers or gaskets, it is highly recommended to also replace all 34 of the rubber bolt grommets/seals. These also harden over time and are crucial for applying correct and even pressure to the cover for a good seal.
Replacement Information
Replacing the valve cover gaskets on the S85 V10 is a labor-intensive job that requires patience and careful attention to detail. While a straightforward process of removing bolts and components, the tight access and number of parts to be removed make it a challenging DIY for beginners. Components like the intake plenum, airboxes, and fuel lines must be disconnected and moved.
- Difficulty: 4 out of 5
- DIY Feasible: Yes, for experienced mechanics.
- Estimated Time: 5-8 hours.
- Key Steps: Disconnect battery, remove intake plenum and airboxes, disconnect fuel line (use caution), remove ignition coils, disconnect sensor wiring, unbolt and carefully remove the covers. 🎬 Watch this step-by-step S85 valve cover gasket replacement guide. Thoroughly clean the cylinder head mating surface before installing the new gasket and cover.
Cost Breakdown
| Part/Service | Estimated Cost |
|---|---|
| New OEM Valve Cover (Each) | $580 - $700 |
| Used OEM Valve Cover (Each) | $150 - $300 |
| New Aftermarket Valve Cover Gasket Kit | $80 - $150 |
| Shop Labor (Gasket Replacement) | $1000 - $2200 |
Frequently Asked Questions (FAQ)
Can I just replace the gasket, or do I need to replace the whole valve cover?
In most cases, the leak is caused by a hardened rubber gasket, and replacing just the gasket set (including spark plug tube seals and bolt grommets) will solve the problem. However, you should replace the entire cover if it is cracked, warped, or if the internal coating in the gasket channel is peeling, as a new gasket will not seal on a damaged surface.
Is this a difficult DIY job for a 2008 BMW M5?
Yes, this is considered a moderately difficult to advanced DIY job. While it doesn't require highly specialized tools, it is time-consuming and involves removing many components to access the covers, including the intake plenum and fuel lines. Patience and organization are key. It is rated a 4 out of 5 on a difficulty scale.
What happens if I don't fix a leaking valve cover gasket?
Ignoring a leak can lead to several problems. The burning oil smell is unpleasant and can fill the cabin. A significant oil leak can damage the alternator if it's located below the leak. Oil leaking into the spark plug tubes can cause engine misfires, poor performance, and damage to ignition coils and catalytic converters. In extreme cases, a severe leak onto a hot exhaust manifold poses a fire risk.
Are the valve covers for the M5 and M6 the same?
Yes, the 2006-2010 BMW M5 (E60) and 2006-2010 BMW M6 (E63/E64) share the same S85 V10 engine, and therefore use the same left and right valve covers.
Helpful Videos
Technical Specifications
OEM Part Numbers: 11127834619 11127834622 11127835173 11127891022 11127891023
Material: Cast Magnesium Alloy
We Have This Part in Stock
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.
- BMW M5:
- BMW M6:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Known Issues, TSBs, and Recalls
- Symptoms of a Failing Valve Cover or Gasket
- 1. Burning Oil Smell
- 2. Visible Oil Leaks and Smoke from Engine Bay
- 3. Oil in Spark Plug Wells
- 4. Low Engine Oil Level
- Buying a Used S85 Valve Cover
- Replacement Information
- Cost Breakdown
- Frequently Asked Questions (FAQ)
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