DIY Valve Cover Gasket Replacement: Step-by-Step Guide (Save $150-$400)
On most inline-4 engines, this is one of the best first-time DIY repairs. The valve cover is on top of the engine, fully accessible, and the job requires only basic hand tools. Here is exactly how to do it and how much you will save.
DIY Difficulty by Engine Type
| Engine | Difficulty | DIY Time | Tools | Recommended For |
|---|---|---|---|---|
| Inline-4 (Civic, Camry, Corolla) | 1/5 | 1-2 hrs | Basic socket set, torque wrench | Beginners welcome |
| V6 Front Bank | 2/5 | 1.5-2.5 hrs | Socket set, torque wrench, extensions | Some experience helpful |
| V6 Rear Bank (transverse) | 4/5 | 3-5 hrs | Full set + intake manifold removal | Experienced DIY only |
| V8 (longitudinal) | 2/5 | 2.5-4 hrs | Socket set, torque wrench | Moderate, but two covers |
| Boxer (Subaru) | 3/5 | 3-5 hrs | Socket set, swivel adapters | Awkward angles, patience needed |
| Euro integrated (BMW) | 5/5 | N/A | Specialized BMW tools | Shop only, integrated cover |
Tools and Parts Needed
Tools
- Socket set (10mm, 12mm, 14mm)$20-$40
- Torque wrench (ft-lb, 10-80 range)$25-$40
- Plastic gasket scraper$5-$10
- RTV silicone sealant (Permatex Ultra Grey or Black)$8-$12
- Brake cleaner (for surface prep)$4-$6
- Shop rags / paper towels$3-$5
- Nitrile gloves$5-$8
Total tool cost if starting from scratch: $70-$120. These tools will last decades.
Parts
- Valve cover gasket kit (includes tube seals)$15-$50
- RTV sealant (Permatex Ultra Grey)$8-$12
- Spark plugs (optional, if due)$40-$80
- PCV valve (optional, if accessible)$10-$30
Total parts cost: $25-$120 (gasket + sealant minimum, add spark plugs and PCV if due).
Step-by-Step Replacement (Inline-4)
Disconnect the battery
Remove the negative terminal. This prevents accidental shorts when disconnecting electrical connectors near the valve cover.
Remove the engine cover
Most modern cars have a plastic engine cover held on by clips or bolts. Pull it off and set it aside.
Disconnect electrical connectors
Unplug the ignition coil connectors and any sensors attached to or near the valve cover. Take a photo first so you remember where everything goes.
Remove ignition coils
Each coil is held by one bolt (usually 10mm). Pull them straight up and out of the spark plug wells. Label them so they go back in the correct cylinder.
Remove spark plugs (optional)
If your spark plugs are within 10,000 miles of their change interval, pull them now while you have easy access. You save the labor of removing the coils again later.
Remove valve cover bolts
Usually 8-12 bolts in 10mm or 12mm. Remove them in a reverse-torque pattern (outside edges first, center last). Set bolts aside in order.
Break the valve cover loose
Tap the cover gently with a soft mallet or rubber hammer. Never pry with a metal screwdriver against the aluminum head surface. The cover should pop free after a few taps.
Remove old gasket
Peel the old gasket off the valve cover and the cylinder head surface. Inspect both surfaces for damage.
Clean both mating surfaces
This is the most important step. Use a plastic scraper (never metal on aluminum) to remove all old gasket material. Wipe both surfaces with brake cleaner and a lint-free rag until completely clean. Any residue will cause the new gasket to leak.
Install new gasket
Modern rubber gaskets press-fit into the groove on the valve cover. Seat the gasket into the groove, ensuring it sits flat all the way around. Also install new spark plug tube seals (press them into the valve cover openings).
Apply RTV sealant
Apply a thin bead of RTV at the half-moon areas (where the cam caps meet the head surface) and at any corners or joints where the camshaft bearing caps intersect the valve cover surface. Do not over-apply. A thin bead is better than a thick glob that squeezes into the engine.
Install valve cover
Place the cover on the head and hand-tighten all bolts first. Then torque in a center-outward star pattern to spec (typically 8-12 ft-lbs for most vehicles). Check your vehicle-specific torque spec. Over-torquing is the most common DIY mistake and will warp the cover.
Reinstall components
Reinstall spark plugs (if removed), ignition coils, electrical connectors, and the engine cover. Reconnect the battery.
Start and inspect
Start the engine and let it idle for 5 minutes. Visually inspect the valve cover seam for any oil seepage. Check again after driving for 20-30 minutes. A small amount of smoke from RTV burning off is normal.
Common DIY Mistakes to Avoid
Over-torquing bolts
Use a torque wrench, not your gut. 8-12 ft-lbs feels very light. Over-torquing warps aluminum covers and cracks plastic ones.
Not cleaning surfaces properly
Spend 20-30 minutes on surface prep. Every speck of old gasket or sealant is a future leak point.
Forgetting RTV at joints
The half-moon areas and corner joints need RTV because the gasket alone cannot seal these transitions.
Reusing spark plug tube seals
Always replace tube seals when doing the gasket. They are cheap and included in most kits. Old tube seals leak within months.
Using metal scrapers on aluminum
Metal gouges aluminum and creates low spots that leak. Use plastic scrapers and brake cleaner only.
Not letting RTV cure
Wait 15-20 minutes after applying RTV before installing the cover. This gives it initial tack to stay in place.
Total DIY Cost vs. Shop Cost
| Item | DIY | Independent Shop | Dealer |
|---|---|---|---|
| Parts | $25-$60 | $15-$50 | $30-$80 |
| Labor | $0 | $80-$250 | $120-$400 |
| Total | $25-$60 | $200-$400 | $350-$600 |
| You Save | $150-$540 | baseline | baseline |
When NOT to DIY
- V6 rear bank requiring intake manifold removal (unless you are experienced with engine work).
- BMW, Audi, or Mini with integrated plastic valve covers. The PCV system reassembly is complex and error-prone.
- Any engine where you are not comfortable with the access. If you have to remove the turbocharger or exhaust manifold, consider a shop.
- If you do not own a torque wrench and are not willing to buy one. Over-torquing ruins the job.
Shop Costs
What it costs if you go to a professional.
Cost by Engine Type
Which engine types are easiest to work on.
Related Repairs
What else to replace while the cover is off.
More Savings Tips
9 ways to reduce the repair cost.