A Mechanic's Guide to the Engine Valve Cover Gasket Set for the 2005-2007 Mercury Montego
Leaking oil and smelling burning odors from your Montego? Your valve cover gaskets are the likely cause.
- The correct model years for the Mercury Montego are 2005-2007, not 2003-2007.
- Replacing the rear valve cover gasket is much more difficult and costly than the front one because the intake manifold must be removed.
- A burning oil smell is the most common symptom of a failing valve cover gasket.
- While doing this repair, it is smart to also replace the spark plugs and intake manifold gaskets to save on future labor.
Is Your Montego's Valve Cover Gasket Failing?
The 3.0L V6 engine in your Mercury Montego is generally reliable, but over time, heat and age will cause the rubber valve cover gaskets to become hard and brittle. When this happens, they crack and can no longer hold a seal. The signs of a leak are usually easy to spot.
Common Symptoms of a Leak
- Burning Oil Smell: This is the most common sign. Oil drips from the leaking gasket onto the hot exhaust manifold below, creating a distinct and unpleasant burning smell that you may notice inside or outside the car.
- Visible Oil and Grime: Look at the top of your engine. You will likely see oily residue and caked-on dirt on the valve covers and running down the side of the engine block.
- Low Engine Oil: A steady leak will cause your oil level to drop, forcing you to top it off between oil changes.
- Engine Misfires: If oil leaks into the spark plug tubes, it can foul the spark plugs. This can cause the engine to run rough, hesitate during acceleration, and trigger the Check Engine Light with misfire codes (e.g., P0300-P0306).
Pro Tip: Front vs. Rear Gasket Replacement
Your Montego's V6 engine is mounted sideways (transversely). This means one valve cover is at the front of the engine bay (easy to see and access) while the other is at the back, tucked against the firewall. Replacing the rear gasket is a much bigger job because the entire upper intake manifold must be removed to access it. This significantly increases the labor time and cost. If you are paying a shop to replace one gasket, it is highly recommended to replace both at the same time to save on labor costs in the long run.
Choosing the Right Aftermarket Gasket Set
When shopping for a replacement, you don't necessarily need to go to the dealer. High-quality aftermarket brands offer reliable performance, often at a better price. For this specific repair, you want a complete kit that includes both main gaskets and the spark plug tube seals.
- Victor Reinz: This is a well-regarded brand that manufactures gaskets for many original equipment (OE) suppliers. Their kits are known to be made from quality, pliable rubber that fits correctly and provides a durable seal, making them a trusted choice for this repair.
Aftermarket gaskets from reputable brands like Victor Reinz are a solid choice and can be considered equivalent in quality to the original OEM parts for this application.
Cost of Replacing a Mercury Montego Valve Cover Gasket Set
The total cost depends heavily on whether you are replacing just the front gasket or both. Because the rear gasket requires removing the intake manifold, the labor cost is much higher for a complete job.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Gasket Set | $107 - $142 |
| Shop Labor (Front & Rear) | $250 - $650 |
| Total Estimated Cost (Full Job) | $357 - $792 |
Cost estimates are for both front and rear gaskets and can vary by location and shop.
Frequently Asked Questions (FAQ)
Are there any recalls for the Montego valve cover gaskets?
No. While there were recalls for the 2005-2007 Mercury Montego for issues like door latches and fuel tank straps, none were issued for leaking valve cover gaskets.
Can I replace the gaskets myself?
An experienced DIY mechanic can perform this job. The front gasket is straightforward. However, the rear gasket is challenging due to the need to remove the upper intake manifold, fuel lines, and various connectors. If you are not comfortable with that level of disassembly, it is best to leave this job to a professional.
Should I use sealant (RTV) on the new gaskets?
Yes, but only in specific spots. A small dab of oil-resistant RTV sealant is required where the timing chain cover meets the cylinder head, as these are natural seam points where leaks can occur. Do not coat the entire gasket in sealant.
What else should I replace at the same time?
Since the intake manifold has to be removed for the rear gasket, it is the perfect time to replace the spark plugs and the intake manifold gaskets. If oil was found in the spark plug tubes, the spark plugs should be replaced. This will save you significant money on future labor costs.
Technical Specifications
OEM Part Numbers: 6F9Z-6584-BA 5F9Z-6584-BA
Fits all 2005, 2006, and 2007 Mercury Montego models equipped with the 3.0L DOHC V6 engine. Set should include both valve cover gaskets, spark plug tube seals, and bolt grommets.
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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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